KR20010006195A - Blood-pool carrier for lipophilic imaging agents - Google Patents

Abstract

Surface-modified lipoprotein-type oil-in-water emulsions useful as blood-pool selective delivery vehicles for lipophilic or lipophilic derivatives of water-soluble phase forming agents. Blood-pool selective delivery vehicles are present in the blood for several hours and exhibit very little initial liver sequestration and clarify within 24 hours from the blood. The average diameter of the oil phase is 150 nm or less to minimize sequestration by the screening endothelial system. The surface of the oil phase is modified with polyethyl glycol-modified phospholipids to inhibit normal interaction with hepatocyte receptor sites. In radiographic imaging, radioactive or stable, synthetic or semi-synthetic polyhalogenated triglycerides, for example 2-oleoylglycerol-1,3-bis [7- (3-amino-2,4,6-tri Iodophenyl) heptanoate] or a fat soluble derivative of a traditional water soluble contrast agent such as aliphatic esters of ipananoic acid, ditrizoic acid and acetrizoic acid may be incorporated into the lipophilic core of lipoprotein type emulsion particles.

Description

BLOOD-POOL CARRIER FOR LIPOPHILIC IMAGING AGENTS}

Conventional water soluble contrast agents for x-ray computed tomography (CT) and magnetic resonance imaging (MRI) diffuse out of the blood rapidly after injection. Thus, angiogenesis relies on, for example, invasive intraarterial injection of a large amount of contrast agent at or near the expected disease site. Despite administration of the pill dose of contrast agent, the buildup lasts only a few seconds. In CT angiography, as a specific example, large amounts (more than 200 ml) of conventional water soluble urethography agents are administered directly to the arteries at rates up to 5 ml / sec. Such rapid administration can cause nausea and vomiting. Since conventional urethragraphers are rapidly distributed throughout the blood space prior to rapid kidney removal, CT scanning should be achieved within 30 seconds while the agent is in the circulation merchant. Intravascular contrast agents are rapidly lost because the agent diffuses into the extravascular space and is nonspecifically distributed throughout the body. Therefore, there is a need for a transport vehicle for CT scanning that can be administered less invasive and prolongs the presence of the agent in the blood.

Several experimental CT agents, including high molecular weight carboxymethyl dextran and microcrystalline granules, were produced to provide extended circulation time in the blood. The iodide version of dextran makes the blood opaque for up to 20 minutes, but noticeably delayed cleansing (more than a day) from the liver. In one example microcrystalline granules comprising solid ethyl ditrizoate having a particle size in the range from 200 to 400 nm are very slowly purified by the reticulum endothelial system (RES) of the liver and spleen. Thus, there is a need for a transport vehicle that circulates for extended periods of time in the blood but will metabolize and cleanse from the whole body within an acceptable time.

In addition to the experimental formulations described above, the formation of several liposome oil-in-water emulsions that have been found to contain phospholipid polyethylene glycol (PEG) or PEG derivatives reduce RES uptake and parenterally administered transport vehicles and prolong the blood half-life of the vehicle. It became. Although liposomes and lipoproteins share some common structural lipid components and significantly overlap in particle size, there are significant differences in the particle structure and the segregation mechanism of the two particulates by their respective target tissues.

Liposomes artificially prepared from lipid vesicles formed by single or multiple polar lipid bilayers consisting primarily of phospholipids and cholesterol surrounding the aqueous compartment are essentially granular and therefore have the potential to deliver the agents contained therein to the RES. The investigator attempted to load liposomes with ionic and nonionic water soluble urography imaging contrast agents. However, stabilization of the resulting liposomes against contrast agent loss from the bilayer proved to be a major problem. In addition, the incorporation of the natural lipophilic formulation into the bilayer is limited by the low dose of lipophilic formulation to be incorporated into the membrane matrix and the limited loading capacity of liposomes.

Lipoproteins, on the other hand, are natural oil-in-water emulsions composed of a monolayer of polar (bilateral) lipids surrounding the neutral lipid core consisting of cholesteryl esters and triglycerides. Various apolipoproteins are associated with polar monolayers of these lipid-transporting particles. Each apolipoprotein plays a role in the enzyme-mediated metabolism of various classes of lipoproteins or as a recognition factor for tissue-selective receptor-mediated uptake. Liposomes deficient in these specific surface recognition proteins are rapidly sequestered by macrophages of RES in lungs, liver (Camper cells), spleen and bone marrow. Liposomal biodistribution can be somewhat tuned by alteration of surface charge, particle size and chemical modification of surface components, although much of the modified liposome material is still sequestered by macrophages. The problem with RES-mediated particulates, for example the liposomes described above, is toxic. The glandular imaging agent of the macrophasic dose is associated with the expansion of the hepatic champfer cells causing the synergistic dense of the macrophages releasing toxic mediators and their resulting activation.

Thus, there is a great need in the art for less toxic delivery vehicles or compositions that include diagnostic contrast-producing oil-in-water emulsions that have extended blood circulation time but are clarified within a suitable time from the whole body.

It is therefore an object of the present invention to provide lipophilic derivatives of water-soluble preparations such as delivery vehicles, more particularly blood-pool selective surface-modified oil-in-water emulsions or radiocontrast agents for the transport of lipophilic preparations.

Another object of the present invention is to provide a lipoprotein type oil-in-water emulsion which achieves prolonged retention in circulation by avoiding sequestration by blood-pool selective delivery vehicles, in particular RES.

It is another object of the present invention to provide a blood-pool selective delivery vehicle that is substantially free of liposome contamination.

Another object of the invention is to select a delivery vehicle, specifically intravenous administration (versus invasive arterial catheter insertion) followed by blood-pool selective maintenance for extended periods of time (belonging to 1-2 hours versus seconds) in the blood. It is to provide a surface-modified oil-in-water emulsion.

The above and other objects are achieved by the present invention, which is a surface-modified synthetic oil-in-water emulsion similar to endogenous lipoproteins for use in biological natural transport systems. The surface-modified oil-in-water emulsions of the present invention induce phospholipids by interfering with the binding of apophospholipids and / or opsonins and emulsion particles, which mediate cellular uptake and circulation elimination of the vehicle to prolong the retention time in the blood. Modified to polyester glycols or polyethylene glycol derivatives. Diagnostically, therapeutically or biologically active or inactive lipophilic agents or lipophilic derivatives inserted into the lipid core of the emulsion are retained in the blood.

According to the invention, the average oil phase particle size is 50 to 150 nm (weighted number), has a narrow size distribution (50 to 250 nm), and up to 2% of the particles fall outside of the range (ie More than 250 m). The emulsion should not have detectable particles having a diameter of 1 μm or more. In addition, the emulsion should not be contaminated with liposomes.

In a composition aspect of the invention, the synthetic oil-in-water emulsion of the invention has the following form:

1. lipophilic component 50% or less (w / v);

2. emulsifier 10% or less (w / v);

3. Cholesterol 5% or less (w / v);

4. up to 5% (w / v) of PEG or PEG-derivatives of phospholipids;

5. osmotic modifier 5% or less (w / v);

6. optionally, 1% or less antioxidant (w / v); And

7. Water to final volume.

Types of formulations that can be administered by incorporation of the synthetic oil-in-water emulsion of the invention into the lipophilic core are lipophilic contrast agents and / or lipophilic derivatives of conventional water soluble contrast agents. The lipophilic core component may comprise up to 50% (w / v) of the emulsion, preferably about 10% to 40% (w / v). The lipophilic core may comprise pharmaceutically acceptable fats or oils of natural, synthetic or semi-synthetic origin, which are pharmacologically inert nonpolar lipids that will be located in the lipophilic core of an oil-in-water emulsion. Specific examples include triglycerides, such as triolein, high purity natural triglycerides (obtained from various sources such as Sigma Chemical Company, St. Louis, Missouri) or oils of animal or plant origin, such as soybean oil, Safflower oil, cottonseed oil, canola oil, fish oil and other biocompatible oils.

In a preferred embodiment, the lipophilic core includes lipophilic contrast agents or lipophilic derivatives of water soluble contrast agents that can be used for diagnostic purposes. For diagnostic purposes, exemplary agents include halogenated triglycerides such as iodide or fluorinated triglycerides; Perfluorinated lower alkyl; Or aliphatic esters of conventional water soluble contrast agents, such as, but not limited to, aliphatic esters of ipananoic acid, these formulations may contain stable or radioactive isotopes of halogen. The term "contrast agent" or "imaging agent" is used herein to denote a formulation that is generally useful for an imaging modality.

In a particularly preferred embodiment, the lipophilic core comprises a mixture of at least one pharmaceutical inert (or inert) oil with a molar ratio in the range of 0.1 to 3 contrast medium. Based on weight / weight (w / w), the ratio of inert oil to contrast agent is from 0.1: 1.0 to 2: 1, more preferably 1: 1. Preferably, the lipophilicity of each core component corresponds to ensuring proper blending of the lipid component.

In the iodide embodiment, iodine containing lipids of the type known in the art can be used. Such lipids include iodide fatty acids in the form of glycerol or alkyl esters. In a particularly preferred embodiment, however, the iodine containing lipid is a synthetic aromatic compound of known purity stabilized against in vivo degradation of iodine bonds in vivo. Illustrative examples of radioactive or nonradioactive halogenated triglycerides useful in the practice of the present invention include US Pat. No. 4,873,075, filed Oct. 10, 1989; US Patent 4,957,729, filed March 3, 1992; And iodide triglycerides of the type described in US Pat. No. 5,093,043, filed March 3, 1992. Examples of iodide triglycerides include 2-oleoylglycerol-1,3-bis [7- (3-amino-2, such as described in WO 95/31181, filed Dec. 14, 1995, which is incorporated herein by reference. 4,6-triyodophenyl) heptanoate] (DHOG) and 2-oleoylglycerol-1,3-bis [4- (3-amino-2,4,6-triyodophenyl) butanoate] ( DBOG).

Clinically, ¹²³ I, ¹²⁵ I and ¹³¹ I are the most frequently used iodine isotopes with the scanning instruments currently used. Of course, ¹³¹ I-labelled triglycerides can be used for therapeutic purposes as is known in the art. However, any radioisotope of iodine is within the contemplation of the present invention. A list of all iodine isotopes is available (for example, pages Misc. 47-49 of the Merck Index, 11 ^th Edition, and at pages 11-68 to 11-70 of the Handbook of Chemistry and Physics, 72d Edition , CRC Press, 1991-1992). ^{It should be noted that 127} I is a natural stable isotope and is not considered "radioactive".

In fluorinated embodiments, certain examples include stable ( ¹⁹ F) or radioactive ( ¹⁸ F) fluorinated triglycerides, such as glyceryl-2-oleoyl-1,3-bis (tri), similar to the above iodide triglycerides. Fluoromethyl) phenyl acetate. In an alternative embodiment of the invention, the fluorine-containing lipids are esters or triglycerides of perfluoro-t-butyl-containing fatty acid compounds as described in US Pat. Nos. 5,116,599 and 5,234,680, for example 7,7. , 7-trifluoro-6,6-bis (trifluoromethyl) -heptanoic acid or 8,8,8-trifluoro-7,7-bis (trifluoromethyl) octanoic acid. Other examples include perfluorinated low molecular weight hydrocarbons useful as ultrasonic imaging agents as described in US Pat. No. 6,716,597.

In another aspect of the invention, the contrast agent may comprise brominated compounds, such as brominated ethyl esters or monobrominated perfluorocarbons of fatty acids. Of course, these examples are merely illustrative of many specific examples of lipophilic compounds suitable for use in the practice of the present invention and are not intended to be excluded or limited in any way.

Although the invention is described in the sense of delivery of diagnostic contrast agents, it should be understood that therapeutic agents, in particular radiopharmaceuticals, may be included in the lipophilic core of the synthetic oil-in-water emulsions of the invention.

The monolayer surrounding the nonpolar lipophilic core comprises up to about 10% (w / v) of an amphoteric lipid monolayer which may be an emulsifier. Phospholipids of natural, synthetic or semi-synthetic origin are suitable for use in the practice of the present invention. Traditional lipid emulsions for the delivery of contrast agents use natural phospholipids such as soy lecithin and egg phosphatidylcholine (eg, vaginal). In a preferred embodiment of the invention, the emulsion component is a synthetic, semi-synthetic and / or naturally occurring component of known origin, purity and relative concentration. Inappropriate use of egg lecithin (a mixture of phospholipids) and / or crude oil (cotton seeds, poppy seeds, etc.), as in typical prior art emulsions, can produce variable non-renewable compositions.

In certain advantageous embodiments, dioleoylphosphatidylcholine (DOPC) is used as emulsifier or monolayer surfactant. DOPC is a semi-synthetic high purity chemically defined phospholipid emulsifier (available from Avanti Polar Lipids, Alabama, USA). Of course, other surfactants suitable for parenteral use may be substituted for all or part of the polar lipid monolayer component. Natural phospholipids are advantageous because these phospholipids are biocompatible and have a suitable phase transition temperature, ie they are liquid at physiological temperature.

In addition to the foregoing, polyethylene glycol-binding lipids are incorporated into a monolayer. Derived polyethylene glycols having a molecular weight of about 1000 to 6000, for example methoxy polyethylene glycol (MPEG) and / or polyethylene glycol-derived lipids such as phosphatidylethanolamine or distearoyl phosphatidyl Preference is given to MPEG bound to ethanolamine. The PEG component should comprise about 0.1 to 30 mole percent monolayer components to achieve a reduction in the retention time of the contrast medium carried in the blood.

In a preferred embodiment, the synthetic MPEG-linked phospholipids may contain fatty acyl groups, including but not limited to myristoyl, palmitoyl, steroyl, oleyl or combinations thereof. MPEG may be covalently linked to phospholipid residues by succinate, carbamate or amide bonds or by other covalent bonds known in the art. MPEG-bound phospholipids are commercially available from Matreya, Inc., Pleasant Gap, Pennsylvania, USA and Avanti Polar Lipids, Inc., Alabama, Alabama, USA. Preferred MPEG-modified phospholipids include MPEG-linked phosphatidylethanolamine; MPEG-2000-1,2-distaroyl; And MPEG-2000-1,2-dioleoylphosphatidylethanolamine. Of course, other polysaccharides modify the surface of monolayers to inhibit the binding of apolipoproteins and / or opsonins to emulsion particles, thereby preventing receptor-mediated absorption and prolonging residence time or residence time of lipid emulsions in the blood. Phospholipids or other stable membrane lipid residues.

The composition also contains sterols, preferably cholesterol in an amount of up to 5% by weight, preferably 0.4 to 0.5% by weight (w / v), in order to stabilize the emulsion. According to a preferred embodiment of the present invention, the molar ratio of sterol to emulsifier, which can be natural, synthetic or semi-synthetic phospholipid, has been found to directly affect particle diameter and size stability. The preferred molar ratio of sterol to phospholipid to achieve the desired size of emulsion is in the range of 0.05 to 0.70, more specifically 0.40 for the transport of iodide triglycerides.

The remainder of the emulsion formulation comprises bulk or aqueous phase containing up to 5% (w / v) USP glycerol. In practicing a preferred embodiment of the present invention, the aqueous phase is a grade of deionized water suitable for parenteral administration. For example, the inclusion of salts (NaCl), such as by the use of 0.9% saline or ionic buffers in the water phase, results in unstable emulsions having an average particle diameter of twice the salt-free emulsion. In addition, the presence of salts in the formulation adversely affects the ability of the emulsion to survive despite the autoclave sterilization and the transient stability of the autoclaved emulsion without significant change in average particle size. Ionic species in the formulation adversely affect the long term stability of the emulsion.

Other conventional additives such as antioxidants, buffers, preservatives, viscosity modifiers and the like can be included in the composition. In particular, 1% or less of an antioxidant such as α-tocopherol, flavinoids, BHT or BHA is recommended. However, additives should not adversely affect the physical and biological properties of the emulsion, such as particle size, storage stability and biodistribution.

The techniques used to formulate oil-in-water emulsions of the invention are important in achieving small particle sizes, uniform size distribution, lack of liposome contamination, and the like.

In accordance with the process of the present invention, the lipophilic components of an oil-in-water emulsion comprising nonpolar core lipids, polar lipid emulsifiers and other lipophilic components such as contrast agents are blended together to form a premixed lipid phase. . The aqueous component is combined and added to the premixed lipids. The premixed lipid phase and aqueous components are homogenized to form a crude oil in water emulsion. Crude oil-in-water emulsions are subjected to ultra-high energy emulsification to produce fine oil-in-water emulsions with an average particle size of 50 to 150 nm and 98% or more particles of 250 nm or less. In a preferred embodiment of the invention, the fine oil-in-water emulsion is subsequently filtered.

In a preferred method embodiment of the invention, the lipid component is initially a Polytron homogenizer (Kinematica GmbH, Lucerne, Switzerland) or Ultra Turrax (operated at 12,500 rpm for at least 5 minutes at 55 ° C. under a nitrogen atmosphere). IKA-Works, Cincinnati, Ohio) is used to blend or homogenize with USP glycerol. The aqueous component is then added to anhydrous glycerol-lipid emulsion and emulsified by high speed mixing or homogenization at 25,000 rpm under the same or similar conditions to form a crude oil-in-water emulsion. The final treatment is an ultra high energy mixing device such as a MicroFluidizer high pressure homogenizer (Model 110S, Microfluidics Corp., Newton, Mass., USA), or US Patent No. 4,533,254, or 10,000 to 30,000 psi, preferably at 35 to 60 ° C. Equivalent devices, such as Emulsiflex (Avestin, Inc., Ottawa, Ontario, Canada) or Manton-Gaulin (APV Gaulin Rannie, St. Paul, Minn.), Preferably operating in a recirculation mode for about 20 minutes or less at about 14,700 to 23,000 psi. Is achieved. After treatment, the emulsion is subsequently passed through sterile water 0.45 μm to 0.22 μm sterile filter. Subsequent filtration removes large particles and provides the potential for endpoint sterilization of the product.

The temperature of the high energy mix is explanatory and should be chosen for the contrast agent. That is, the temperature must be at or above the phase transition temperature or the melting point of the contrast agent or emulsifier (phospholipid or MPEG-linked phospholipid). However, the above range is determined by whether the temperature causes decomposition and dissolution of the components in the composition.

The use of ultra high pressure homogenizers ensures a small particle size with a narrow size range distribution. Conventional systems for forming emulsions, such as homogenizers, sonicators, mills, and stirring systems, provide shear forces to the liquid components, while ultra-high energy mixing devices place the emulsion components under pressure and through small openings. Reduce particle size. Size distribution can be measured by submicron laser photon correlation spectrophotometry (PCS) in a Nicomp 370 dynamic laser light scattering autocorrelator (Nicomp Particle Sizing Systems, Santa Barbara, Calif.) Or similar device. Lipid emulsions suitable for the practice of the present invention will have an average particle size of about 250 nm or less, preferably in the range from 50 to 150 nm, as determined by Nicomp numerical weighted analysis. The particles must have a narrow size distribution and about 98% of the particles fall between 50 and 250 nm. Particles should not be detected with diameters greater than 1 μm.

In the method of the use aspect of the present invention, the oil-in-water emulsion of the present invention containing a contrast enhancer is administered to a mammal and the mammal has reached a stable blood level, i.e. 1 to 30 minutes after injection and at that level. X-ray computed tomography imaging is used before decay. An alternative method of use is to visualize and / or have a suitable oil-in-water emulsion containing a contrast agent suitable for other diagnostic modalities, such as proton magnetic resonance imaging (MRI), ¹⁹ F-MRI, ultrasonography, or scintograms. It can be administered for detection.

The present invention relates generally to oil-in-water emulsions, and more particularly to oil-in-water emulsions, which act as blood-full selective carriers or delivery vehicles for lipophilic phase forming agents, or fat-soluble derivatives of water-soluble phase forming agents incorporated therein.

Understanding of the invention is facilitated by reading the following detailed description in conjunction with the accompanying drawings:

1 is an explanatory diagram of a series of fluorinated or iodide triglycerides, in particular 1,3-disubstituted triacylglycerols, suitable for use in the practice of the present invention.

Figure 2 shows the molecular formula for lipophilic triacylglycerols useful in the practice of the present invention.

3 is a graph of blood radioactivity to% dose / organ versus time in minutes after in vivo administration of DHOG-LE or DHOG-PEG to female Sprague-Dawley rats (n = 3).

4 is a graph of CT density in Hounsfield units (HU) versus time (minutes) after administration of DHOG-LE or DHOG-PEG in the blood of female New Zealand white rabbits.

5 is a graph of pulmonary arterial pressure and heart rate as a function of time (minutes) after administration of a contrast agent containing emulsion of the invention to pigs.

The oil phase particles of the invention have a lipophilic lipid core surrounded by a monolayer of phospholipids, stabilizers such as cholesterol, polyethylene glycol-derived components which may be. The lipid core contains pharmaceutically inert fats or oils such as triglycerides (eg triolein) and / or lipophilic agents such as radioactive or lipophilic derivatives of water soluble contrast agents. . The monolayer's polar moiety (eg, the polar head of the phospholipid emulsifier) is directed out to the bulk water phase while the monolayer's nonpolar moiety (tail of the phospholipid emulsifier) is oriented towards the lipid core. Purely lipophilic compounds carried in accordance with the principles of the present invention are almost all present in the core of the lipid particles below the monolayer.

Examples of lipophilic contrast agents include agents of the type reported by Weichert et al., Weichert, et al., J. Medicinal Chemistry (1986, 29: 1674-82); (1986, 29: 2457-65); and (1995, 38: 636-36)], but also include, but are not limited to, fat soluble derivatives of other traditional water soluble contrast agents [Principles of Medicinal Chemistry (4 ^th edition), edited by William Foye, Chapter 43. Aliphatic esters of yopanoic acid, ditrizoic acid and acetrizoic acid, as described in RE Counsell and JP Weichert authors, Williams and Wilkins, 1995.

US Patent No. 4,873,075 to October 10, 1989, which is incorporated herein by reference in its entirety as illustrative examples of radio or nonradioactive polyhalogenated triglycerides that are particularly suitable for use in the practice of the present invention; US Patent No. 4,957,729, filed September 18, 1990; And US Patent No. 5,093,043, filed March 3, 1992. The iodide arylaliphatic triglyceride homologues of this patent have a triglyceride backbone structure, i.e., 1,3-disubstituted with 3-substituted 2,4,6-triiodophenyl aliphatic chains or monoiodophenyl aliphatic chains or 1,2,3 -It is substituted for three. In a preferred embodiment, all aliphatic chains are saturated or unsaturated aliphatic hydrocarbon chains of the type found in natural fatty acids, whether iodide residues or open positions on the triglyceride backbone structure. Natural fatty acids include those containing about 4 to 20 carbons, such as palmitic acid (16), palmitoleic acid (16: 1), oleic acid (18: 1), linoleic acid (18: 2), arachidonic acid (20: 4) and the like.

Specific examples include glyceryl-2-palmitoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) iophanoate; Glyceryl-2-palmitoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) dodecanoate; Glyceryl-2-palmitoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) acetate; Glyceryl-2-palmitoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) propionate; Glyceryl-1,2,3-triyophanoate; Glyceryl-1,2,3-tri-12- (3-amino-2,4,6-triyodophenyl) dodecanoate; Glyceryl-1,3-di-17- (3-amino-2,4,6-triyodophenyl) heptadecanoate; Glyceryl-1,2,3-tri-3- (3-amino-2,4,6-triyodophenyl) propionate; Glycerol-2-palmitoyl-2-palmitoyl-1,3-di-15- (p-iodophenyl) pentadecanoate; Glyceryl 2-oleoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) butyrate; Glyceryl-2-oleoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) -pentanoate, glyceryl 2-oleoyl-1,3-di- (3- Amino-2,4,6-triyodophenyl) -hexanoate; Glyceryl 2-oleoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) -octanoate; Glyceryl 2-oleoyl-1,3-di- (3-amino-2,4,6-triyodophenyl) -heptanoate (DHOG) and the like. A detailed description of the 1,3-disubstituted triacylglycerol preparation described above is described in co-pending patent application No. 08 / 243,596 dated May 16, 1994.

In the studies reported herein, iodide triglycerides are synthesized and radioiodized to ¹²⁵ I by isotope exchange in the melt of pivalic acid according to methods known in the art. Of course, radioiodination of either iodide triglycerides or intermediates in the synthetic route can be accomplished by various techniques known to those skilled in the art.

The following specific examples illustrate some of the many possible lipophilic contrast agents that can be delivered to the blood-pool in oil-in-water emulsions prepared according to the principles of the present invention.

Example 1:

With reference to FIG. 1, the general reactivity is iodide or fluorinated triglycerides, in particular 1,3-disubstituted triglycerol or ω- (3-amino-2,4,6-triiodophenyl suitable for use in the process of the invention. Alkanoate is shown. In an illustrative embodiment of Example 1, compound (22) is 2-monoolein (compound 21) and the corresponding ω- (3-amino-2,4,6-triyodophenyl) alkanoic acid ( Compound 20) is synthesized by two equivalents of dicyclohexylcarbodiimide / 4-dimethylaminopyridine (DCC / DMAP) coupling.

Preparation of ω- (3-amino-2,4,6-triyodophenyl) alkanoic acid:

Synthesis of ω- (3-amino-2,4,6-triyodophenyl) alkanoic acid (Compound 20) has been described by Weichert, et al., J. Med. Chem., Vol. 29, p. 1674 and 2457 (1986)]. Yopanoic acid is commercially available and sold from CGC Organics, Atlanta, Georgia, USA.

Preparation of 2-Oleoylglycerol-1,3-bis- [3-amino-2,4,6-triyodophenyl) alkanoate]:

Alcohol (2-monolein; 1,2,3-trihydroxypropane 2-oleate; 1.0 equiv) in anhydrous CH ₂ Cl ₂ (5 ml / mmol of alcohol), carboxylic acid (ω- (3-amino- A rapidly stirred suspension of 2,4,6-triyodophenyl) alkanoic acid; 1 to 2.1 equivalents) and a catalytic amount of DMAP (0.1 equivalents) is treated with DCC (1.1 equivalents of acid). The resulting mixture is stirred overnight at room temperature under N ₂ , diluted with CH ₂ Cl ₂ and filtered to remove precipitated dicyclohexyl urea. The filtrate is washed with 0.5 N HCl, saturated with aqueous NaHCO ₃ , H ₂ O and brine and then dried (MgSO ₄ ). The solvent is removed in vacuo and the remaining residue is purified by column chromatography to provide the desired ester, compounds 31 to 33 shown in FIG. Compound 31 is a specific example of Compound 22 in FIG. 1.

2-Oleoylglycerol-1,3-bis [7- (3-amino-2,4,6-triyodophenyl) heptanoate] (Compound 31):

DCC (3.62 g, 17.5 mmol) was added to 7- (3-amino-2,4,6-triyodophenyl) heptanoic acid (10.0 g, 16.7 mmol) in anhydrous CH ₂ Cl ₂ (120 ml) following the above procedure. , Stirred for 24 hours with a stirred suspension of 2-monolein (2.83 g, 7.9 mmol) and DMAP (180 mg). After operation, the residue (14.7 g) was obtained and purified by column chromatography on silica gel (10 × 25 cm) eluted with hexanes / EtOAc / CHCl (80: 15: 5) to yield crystallization as a pale yellow oil. Compound 31 shown in FIG. 2 is obtained: yield 9.45 g (79%); IR (CHCl ₃ ) 3450, 3359 (amine), 2915, 2840 (aliphatic CH), 1740 (ester C═O) cm; ¹ H NMR (360 MHZ, CDCl ₃ ), 8.03 (s, 2H, aryl 5-H's), 5.30 (m, 3H, CH = CH, and glycerol 2-H), 4.79 (s, 4H, NH ₃ ), 4.31 (m, 2H, Glycerol OCH _A H _B CH (O) CH _A H _B O), 4.16 (m, 2H, Glycerol OCH _A H _B CH (O) CH _A H _B O), 3.00 (m, 4H, PhCH ₂ 's, 2.32 (m, 6H, O ₃ CCH ₂ 's and oleate O ₃ CCH ₂ ), 2.00 (m, 4H, allyl CH ₂ 's), 1.72 (m, 4H, PhCH ₂ CH ₂ 's), 1.61-1.26 (m, CH ₂ envelope), 0.88 (t, 3H, CH ₃ ), analyte (C ₄₇ H ₄₈ O ₄ N ₂ I ₆ ) C, H.

Ethyl Ipananoate (Compound 32):

DCC (401 mg, 1.9 mmol) was subjected to the above procedure with ipananoic acid (1.02 g, 1.79 mmol) in anhydrous CH ₂ Cl ₂ (30 ml), anhydrous ethanol (75 mg, 1.6 mmol) and DMAP (24 mg) Is added in a stirred suspension for 24 hours. After operation, the residue (900 mg) was obtained and purified by column chromatography on silica gel (6 × 25 cm) eluted with 1% EtOAc / CHCl ₃ to give ethyl iopanoate (75% yield) as pale yellow oil (75% yield). Compound 32) yields 801 mg.

Butyl Ipananoate (Compound 33):

DCC (476 mg, 2.3 mmol) was subjected to the above procedure with ipananoic acid (1.21 g, 2.1 mmol), n-butanol (143 mg, 1.9 mmol) and DMAP (28 mg) in anhydrous CH ₂ Cl ₂ (30 ml). ) Is stirred for 24 hours. After operation, the residue (1.6 g) was obtained and purified by column chromatography on silica gel (6 × 25 cm) eluted with 1% EtOAc / CHCl ₃ to give butyl iphanoate (91% yield) as pale yellow oil (91% yield). Compound 33) yields 1.08 g.

The iodide triglyceride of Example 1 is incorporated into the lipid core of an oil-in-water emulsion by the formulation technique according to the invention as described more fully in the Examples below.

Example 2:

The general format for blood-pool oil-in-water emulsions according to the invention is as follows:

10% (w / v) total lipid (inert oil + contrast agent)

For example, triolein (TO) + DHOG

TO: DHOG (w / w) = 1: 1

0.5% PEG Ingredient

Methyl Polyethylene Glycol (2000) -Distearoylphosphatidylethanolamine

(DSPE)

2.4% (w / v) total phospholipid

For example, DOPC [1.9% (w / v)] + MPEG-DSPE [0.5% (w / v)]

0.4% (w / v) sterols

For example, cholesterol

DOPC + MPEG-DSPE (Molar Ratio) = 0.4

5% (w / v) USP Glycerol

0.6% (w / v) α-tocopherol

Parenteral grade, deionized water as bulk aqueous phase

In a particular example embodiment, Compound 31 and Compounds 32 and 33, which are DHOG, are formulated in an oil-in-water emulsion according to the following method.

Emulsion Example 1:

Subsequently weighed with DHOG (0.7507 g), triolein (0.7509 g), cholesterol (0.0613 g), α-tocopherol (0.0900 g) and MPEG-DSPE (0.0757 g) in a weighed tube, ethanol DOPC (0.2850 g) is introduced. The solvent is removed in a rotary evaporator at 37 ° C. in vacuo and the process is stopped once to rinse the tube with 1.5 ml of additional CHCl ₃ . After completion of solvent removal, the tube is weighed and anhydrous glycerol (0.7530 g) is added to the lipid mixture. The tube is placed in a Polytron homogenizer for 5 minutes preemulsification at 12,5000 rpm under nitrogen atmosphere at 50-55 ° C. 10 ml aliquots of sterile water are added with continuous mixing and then emulsified at 25,000 rpm for 5 minutes under the same conditions. The volume of the crude emulsion is adjusted to 15 ml final volume with additional sterile water. The preparation is transferred to a Model 110-S MicroFluidizer for final emulsification at 18-5200 psi for 10 minutes at 54-55.8 ° C. The emulsion is then passed through a sterile 0.45 mm and 0.2 mm filter unit into a sterile multi-dose vial. The emulsion is equilibrated at room temperature and then the average particle diameter is measured by submicron laser photon correlation spectrophotometry (PCS). The average particle diameter is 74 nm.

Emulsion Example 2:

Ethyl Ipananoate (0.5044 g), Triolein (0.5042 g), Cholesterol (0,0410 g), α-Tocopherol (0,0619 g) and MPEG-DSPE (0.0500 g) in a weighed tube Was weighed and DOPC (0.1900 g) in ethanol solution was added. A 4 ml portion of CHCl ₃ is added to the tube to dissolve the lipid mixture. The solvent is evaporated in vacuo at 37 ° C. as described in Example 1. After solvent evaporation, anhydrous glycerol (0.5014 g) is added to the lipid mixture and emulsified for 5 minutes at 12,5000 rpm in Polytron under a nitrogen atmosphere. A 6 ml aliquot of sterile water is added with continuous mixing and emulsified at 25,000 rpm for 5 minutes at a temperature of about 55 ° C. The crude emulsion is diluted and transferred to the MicroFluidizer to a final volume of 10 ml with sterile water. Final emulsification is performed at 18.200 psi for 10 minutes at 49.2 to 50.9 ° C. The emulsion is passed through a sterile filter into a sterile vial as described in Example 1. The average particle diameter measured by PCS sizing in Nicomp 370 is about 80 nm.

Emulsion Example 3:

n-butyl iphananoate (0.5037 g), triolein (0.5025 g), cholesterol (0,0416 g), α-tocopherol (0,0620 g) and MPEG-DSPE (0.0503 g) Weigh and add DOPC (0.1900 g) in ethanol solution. 5 ml volume of CHCl ₃ is added to the tube to dissolve the lipid. The solvent is evaporated in vacuo at 37 ° C. as described in Example 1. After solvent evaporation, anhydrous glycerol (0.5009 g) is added to the tube containing the lipid mixture. The mixture is emulsified as described in Example 1. The emulsion is diluted and transferred to the MicroFluidizer to a final volume of 10 ml with sterile water. Final emulsification is performed at 18,200 psi for 10 minutes at 50.8 to 51.5 ° C. The emulsion is filtered through sterile multi-dose vials and equilibrated at room temperature. The average particle diameter is about 83 nm as measured by PCS sizing.

Emulsion Example 4:

20% blood-full emulsion is prepared by the following method. DHOG (1.6507 g), Triolein (1.6507 g), Cholesterol (0.0996 g), α-Tocopherol (0.0994 g) and MPEG-DSPE (0.1245 g) were weighed in a weighed tube, DOPC in ethanol solution (0.4700 g) is introduced. 5 ml volume of chloroform is added to the tube to dissolve the lipid mixture. The solvent is evaporated in vacuo at 37 ° C. as described in Example 1. After solvent evaporation, the tubes are weighed before adding anhydrous glycerol (0.8266 g) to the lipid mixture. The tube is placed in Polytron to emulsify the mixture at 12,5000 rpm for 5 min at 55 ° C. under a nitrogen atmosphere. 10 ml aliquots of sterile water are added with continuous mixing and emulsified at 25,000 rpm under the same conditions. The emulsion is diluted and transferred to the MicroFluidizer to a final volume of 16.5 ml with sterile water. The final emulsification is performed at 18,600 psi for 5 minutes at 42.4-51.4 ° C. The emulsion is filtered through sterile multi-dose vials and equilibrated at room temperature. The average particle diameter measured by PCS sizing is about 66.8 nm.

Emulsion Example 5:

Radiolabeled forms of 10% blood-full emulsions are prepared as follows: DHOG (0.5003 g), triolein (0.5008 g), cholesterol (0.0403 g), α-tocopherol (0.0604 g) and MPEG-DSPE (0.0501 g) is weighed into a weighed tube and subsequently weighed to introduce DOPC (0.1900 g) in ethanol solution. 5 ml volume of chloroform is added to the tube to dissolve the lipid component. The solvent is evaporated as described in the examples. A 0.25 ml aliquot of ¹²⁵ I-DHOG in CHCl ₃ is added to the tube and then washed with additional CHCl ₃ (1.2 ml). Chloroform is evaporated as before. Weigh the tube and add anhydrous glycerol (0.5008 g) to the tube and place in Polytron. The mixture is emulsified at 12,500 rpm for 5 minutes at about 55 ° C. under nitrogen. 6.5 ml aliquots of sterile water are added with continuous mixing and then emulsified at 25,000 rpm for 5 minutes as above. The emulsion is delivered to MicroFluidizer 110-S for final emulsification at 18.200 psi at 54.5-55.5 ° C. for 10 minutes. The emulsion is filtered through a sterile multi-dose vial through a sterile filter unit. The activity of the emulsion is 15.2 mCi / ml.

For comparative purposes, radioactive lipid emulsions containing no PEG residue (DHOG-LE) are as follows:

Emulsion Example 6 (prior art):

A radiolabeled form of 10% DHOG emulsion is prepared as follows: DHOG (0.5004 g), triolein (0.5003 g), cholesterol (0.0472 g) and α-tocopherol (0.0601 g) in a weighed tube followed by The product is weighed in an aliquot, and DOPC (0.2400 g) in ethanol solution is introduced. 4.8 ml volume of ethyl acetate is added to the tube to dissolve the lipid component. The solvent is evaporated as described in the examples. A 0.25 ml aliquot of ¹²⁵ I-DHOG in CHCl ₃ solution is added to the tube and washed with 1.0 ml ethyl acetate: ethanol (2: 1, v / v). The solvent is evaporated as before. Weigh the tube and add anhydrous glycerol (0.5012 g) to the tube and place in Polytron. The mixture is emulsified at 12,500 rpm for 5 minutes at about 55 ° C. under nitrogen. 6.5 ml aliquots of sterile water are added with continuous mixing and then emulsified at 25,000 rpm for 5 minutes as above. The emulsion is delivered to MicroFluidizer 110-S for final emulsification at 18.200 psi for 10 minutes at 33.5-36.4 ° C. The emulsion is filtered through a sterile multi-dose vial through a sterile filter unit. The activity of the emulsion is 15.7 mCi / ml.

Emulsion Example 7:

30% blood-full emulsions are prepared as follows: DHOG (2.4751 g), triolein (2.4756 g), cholesterol (0.1321 g), α-tocopherol (0.0995 g) and 1,2-distearoyl- sn-glycero-3-phosphoethanolamine-N- [poly (ethylene glycol) -2000] (MPEG-DSPE 2000; 0.1657 g) was subsequently weighed in a weighed tube, DOPC in ethanol solution (0.6262 g) is introduced. 5 ml volume of chloroform is added to the tube to dissolve the lipid component. The solvent is evaporated in vacuo at 37 ° C. as described in Example 1. After evaporating the solvent, the tube is weighed before anhydrous glycerol (0.8265 g) is added to the lipid mixture. The mixture is placed into Polytron to emulsify at 12,500 rpm for 5 minutes at about 55 ° C. or less under a nitrogen atmosphere. A 9 ml aliquot of sterile water is added to the anhydrous emulsion with continuous mixing and then emulsified at 25,000 rpm for 5 minutes under the same conditions. The emulsion is diluted to 16.5 ml total volume and then transferred to the MicroFluidizer. The final emulsification is carried out at 43.1 to 55.2 ° C. for 17,000 for 5 minutes. The emulsion is filtered through a sterile multi-dose vial through a sterile 0.45 μm to 0.2 μm filter assembly and equilibrated at room temperature. The average particle diameter measured by PCS sizing is about 96 mn.

Example 3:

Biodistribution Research

Radioactive emulsions of iodide triglycerides DHOG are prepared by the techniques described in the corresponding hepatocyte-selective forms of emulsion example 5 (DHOG-PEG) and emulsion example 6 (DHOG-LE).

The emulsion is administered intravenously (tail vein) into normal female Sprague-Dawley rats at a radiation dose of 50 mg I / kg bioweight for biodistribution studies. Blood samples are taken and analyzed for radioactivity before and after a predetermined interval after in vivo administration of the formulation. 3 shows the results of this pharmacokinetic study in FIG. 3, which is a graph of blood radioactivity to% dose / organ versus time in minutes after in vivo administration of DHOG-LE or DHOG-PEG to female Sprague-Dawley rats (n = 3). Is shown.

Liver cleansing of DHOG-LE from blood is rapid and by 60 minutes, about 5% of the injected dose is present in the blood. There is a slight increase in blood levels associated with liver repackaging with other lipoproteins from 1 to 3 hours and subsequent release is released back into the bloodstream. Blood radioactivity remains elevated for up to 2 hours after administration of DHOG-PEG under the same conditions. One hour after administration, for example, at least 56% of administered DHOG-PEG is present in the blood as compared to 4.2% of hepatocyte-selective DHOG-LE emulsions alone.

In another study, tissue distribution results are obtained by administering radiolabeled DHOG-PEG of emulsion Example 5 (17 μCi / ml, 5 μCi / animal) to female Sprague-Dawley rats (178-218 g). Rats are bled at predetermined time points (n = 3 for each time point) after injection of the radiolabeled emulsion into the tail vein. A total of 13 tissues are excised, the low-measure weight is weighed and the radioactivity analyzed by a gamma counter. Results are expressed as% infusion dose / gram (concentration) or% infusion dose / organ (blood, liver, spleen) at 5 minutes, 30 minutes, 1 hour, 3 hours and 24 hours.

The results shown in Table 1 show that the surface-modified emulsions of the present invention are present in the blood for at least 3 hours. However, by 24 hours, the blood radioactivity of DHOG-PEG reaches baseline. This is in sharp contrast to the hepatocyte-selective version that is sequestered and cleared after 30 minutes or less from the blood (FIG. 3 and Table 2, showing the results of similar tissue distribution studies conducted with DHOG-LE). The differences between blood, plasma, liver and spleen in water are significant. These results indicate that PEG surface-modification affects the pharmacokinetics of iodide triglyceride molecules.

In vivo imaging

Computed tomography studies are performed in normal female New Zealand white rabbits using the DHOG-PEG and DHOG-LE of Emulsion Example 1 and the corresponding non-radioactive forms of Emulsion Example 6. The results are shown in FIG. 4, which is a graph of CT density in Hounsfield units (HU) versus time (minutes) after administration of DHOG-LE or DHOG-PEG in the blood of female New Zealand white rabbits. Blood levels are elevated in up to 2 hours after administration. However, follow-up CT studies completed 24 hours after the initial administration show that blood levels drop essentially to baseline.

Pulmonary Hypertension Research

To assess the effect of blood-pool selective oil-in-water emulsions on hemodynamic parameters, the emulsion of Example 1, which is a 10% emulsion of iodide DHOG (60 mg I / kg), is administered to pigs. Swine has a very high number of RES cells in the lung and thus serves as an indication of granular-induced pulmonary hypertension.

The pressure transducer is placed in the right pulmonary and abdominal aorta of the female pig (21 kg). Heart rate is monitored by EKG. Anesthesia is initially induced with telazole (7 mg / kg) / xylazine (2.2 mg / kg) IM and subsequently maintained with halotane. The emulsion is administered intravenously over a 5 minute time through the ear vein at a rate of 10 ml / min, followed by a 10 ml normal saline flush. Pressure and heart rate are measured every minute for the first 15 minutes after injection and then every 5 minutes until 90 minutes after injection. The results are shown in FIG. 5, which is a graph of pulmonary arterial pressure and heart rate versus time after infusion.

With respect to FIG. 5, the arrows indicate the start and end points of the injection. The heart rate is not affected and the lung pressure simply rises temporarily (4-5 mm Hg) during the infusion phase and immediately returns to the baseline level. This indicates that the emulsion of the present invention does not affect the hemodynamic parameters.

Example 4:

In a particularly advantageous embodiment of the invention, the hepatocyte selective oil-in-water emulsion is co-administered with the blood-pool preparation of the invention. Liver-selective granules (hepatocyte-selective or Kupffer cell-selective) rapidly purify from blood and result in low density for liver tissue surrounding the blood. Isolation of small tumors is very difficult and also appears to be low density areas from small vasculature in the size range below 5 mm. To compensate for this problem, DHOG-PEG (Example 1) and hepatocyte selective DHOG-LE (emulsion Example 6, non-radioactive form) are co-administered with the rabbits that produce VX2 tumors.

Rabbits (average weight 2.5 kg) are inoculated directly into the liver parenchyma with VX2 carcinoma to produce a total of eight plastic lesions (2-10 mm). After 10 days, the rabbits are scanned using iodide microgranular emulsion (200 mg I / kg) after 24 hours with a number of techniques including spiral in vivo enhanced non-contrast (600 mg I / kg iohexol). Tissue density measurement (HU) consists of liver, lesions and blood (lower aorta). Tumor morphology is evidenced by gross pathological examination.

Hemodynamic analysis and CT studies indicate that the blood-pool formulations of the present invention remain on the blood-pool for at least 2 hours after in vivo administration. In fact, the blood density in normal rabbits is 95.1 ± 5.8 HU at 120 minutes compared to 90.7 ± 6.1 HU immediately after injection.

Normal liver enhancement to the emulsion results in a pattern that is slightly more granular than yohexolo. Intrahepatic vascular system is well enhanced (aorta = 127.4 HU at 64 minutes after injection). Tumors are significantly enhanced with iohexol (+40.1 HU) in contrast to emulsion (+2.3 HU, p <0.051). Enhancement of liver tissue is greater for iohexol (+66.8 HU) than for emulsion (+31.6 HU), but liver-to-lesion differences encourage emulsion due to lack of tumor enhancement (31.8 vs 28.8). The lesions are optionally better described using emulsions due to the sharp edge definition.

Technology Lesions <1 cm Lesion ＞ 1 cm all Non-contrast 33.3 83.3 51.5 In vivo Yohexol 49.3 97.6 67.6 Just ITG Blood-Pool 68.5 87.5 75.6 combination 72.2 95.2 80.7 ^{* *} p <0.05 vs. iohexol

The results listed in Table 3 indicate that the formulation makes it opaque to improve sensitivity and reliability upon detecting very little tumors in both hepatocytes and blood. It should be noted that receptor-mediated hepatocyte-selective emulsion DHOG-LE significantly enhances the liver within 15 to 30 minutes after infusion. Blood-pool enhancement occurs temporarily after in vivo administration of the hepatocyte-selective formulation, and then rapidly decreases as the agent is sequestered into the liver. The blood-pool formulations of the present invention do not enhance the liver for the first two hours after infusion. Therefore, simultaneous administration of hepatocyte-selective lipid emulsions and blood-full lipid selective emulsions of the invention advantageously results in enhancement of normal liver parenchyma and liver / systemic vascular system without significant tumor enhancement.

Although the above embodiments relate to vehicles and / or contrast agents useful for CT imaging, lipophilic or lipophilic derivatives of water soluble preparations useful in other imaging modalities, such as MRI preparations, ultrasound preparations or radiopharmaceuticals are It is considered within the invention.

Oil-in-water emulsions of the invention are typically suitable for parenteral administration to a mammalian subject by intravenous administration. However, intramuscular, subcutaneous, intraperitoneal and other delivery routes are contemplated within the present invention. In addition, oil-in-water emulsions of the invention can be administered by other routes, such as oral. It is a particular advantage of the oil-in-water emulsion of the present invention that it can be administered to the intravenous aorta, at a dose low and sufficiently slow to be well-resistant. The dose level administered is 20 to 250 mg I / kg body weight.

In a method of use of the invention, blood-pool hyperplasia not only provides diagnostic potential for virtually all vascular diseases, including atherosclerosis and an aneurysm, but also has the potential to exhibit organ perfusion defects. In addition, new advances in CT scanner technology, namely the introduction of ultra-fast electron-beam CT scanners, can make these formulations directly useful for cardiovascular imaging without the need for invasive and costly catheterization procedures.

It should also be noted that the animal models selected and used in the studies presented above herein, in particular rats and rabbits, are well known to have liver physiology that closely resembles human liver physiology. In addition, the blood-paste selective for the oil-in-water emulsion of the present invention does not have any adverse effect on the model of swine pulmonary hypertension.

Although the present invention has been described in the sense of particular embodiments and applications, those skilled in the art may, in light of this teaching, create additional embodiments without departing from the scope of the invention and without departing from the spirit of the claimed invention. Accordingly, the drawings and descriptions herein are to be understood as preferred to facilitate an understanding of the invention and should not be construed as limiting the scope of the invention.

Claims (48)

At least one lipophilic or water soluble agent which is surrounded by a monolayer of amphoteric or polar lipids, including emulsifiers, derived polyethylene glycols or polyethylene glycol-binding lipids and sterols, as a component and which is diagnostically or therapeutically active or inactive A surface-modified lipoprotein-type oil-in-water emulsion having a lipophilic core containing a lipophilic derivative of, having an average particle diameter of an oil phase of 50 to 150 nm and having at least 98% of particles of 50 to 250 nm. The oil-in-water emulsion of claim 1, wherein the lipophilic core comprises up to 50% (w / v) of the total emulsion composition. The oil-in-water emulsion of claim 2, wherein the lipophilic core comprises about 10% to 40% (w / v) of the total emulsion composition. The oil-in-water emulsion according to claim 1, wherein at least one lipophilic substance or lipophilic derivative of the water-soluble agent is a pharmaceutically acceptable nonpolar lipid. The oil-in-water emulsion according to claim 4, wherein the pharmaceutically acceptable nonpolar lipid is triglyceride. 6. The oil-in-water emulsion of claim 5, wherein the triglyceride is a biocompatible oil of animal or plant origin. 6. The oil-in-water emulsion according to claim 5, wherein the triglyceride is a synthetic or semi-synthetic lipid. 8. The oil-in-water emulsion according to claim 7, wherein the synthetic or semi-synthetic lipid is triolein. 8. The oil-in-water emulsion according to claim 7, wherein the triglyceride is a halogenated triglyceride. The oil-in-water emulsion of claim 1, wherein the lipophilic core comprises a contrast agent that is a lipophilic substance or lipophilic derivative of at least one pharmaceutically inert nonpolar lipid and a water soluble contrast agent. The oil-in-water emulsion of claim 10, wherein the lipophilic core is a contrast agent that is at least one pharmaceutically acceptable inert nonpolar lipid and a halogenated triglyceride. The oil-in-water emulsion of claim 10, wherein the ratio of pharmaceutically acceptable inert nonpolar lipid to contrast agent ranges from about 0.1: 1.0 to 2: 1 by weight. 13. The oil-in-water emulsion of claim 12, wherein the ratio of pharmaceutically acceptable inert nonpolar lipid to contrast agent is 1: 1 by weight. The oil-in-water emulsion according to claim 1, wherein up to 10% (w / v) of the emulsion is an amphoteric or polar lipid. The oil-in-water emulsion according to claim 14, wherein the amphoteric or polar lipid is an emulsifier. 15. The oil-in-water emulsion of claim 14, wherein the emulsifier is a natural, synthetic or semi-synthetic phospholipid. The oil-in-water emulsion of claim 16, wherein the phospholipid is synthetic or semi-synthetic. 18. The oil-in-water emulsion of claim 17, wherein the phospholipid is dioleoylphosphatidylcholine. The oil-in-water emulsion according to claim 1, wherein 5% (w / v) or less of the emulsion is sterol. 20. The oil-in-water emulsion according to claim 19, wherein the sterol is cholesterol. 20. The oil-in-water emulsion of claim 19, wherein about 0.4 to 0.5% (w / v) of the emulsion is sterol. 22. The oil-in-water emulsion according to claim 21, wherein the molar ratio of cholesterol to emulsifier is from 0.05 to 0.70. The oil-in-water emulsion according to claim 1, wherein the emulsion further comprises 5% (w / v) osmotic agent. The oil-in-water emulsion according to claim 23, wherein the osmotic regulator is anhydrous glycerol. The oil-in-water emulsion of claim 1, further comprising an amount of antioxidant sufficient to prevent oxidation of the emulsion. The oil-in-water emulsion according to claim 25, wherein the antioxidant is α-tocopherol. Claim 26 The oil-in-water emulsion of claim 1, wherein the emulsion comprises up to about 5% (w / v) derived polyethylene glycol or polyethylene glycol-binding lipids. 27. The oil-in-water emulsion of claim 26, wherein the derived polyethylene glycol or polyethylene glycol-binding lipid comprises from about 0.1 to 30 mole percent monolayer components. The method of claim 26, wherein the derived polyethylene glycol or polyethylene glycol-binding lipids are MPEG-linked phosphatidylethanolamine, MPEG-2000-1,2-distearoyl and MPEG-2000-1,2-dioleoyl An oil-in-water emulsion selected from the group consisting of phosphatidylethanolamine. 27. The oil-in-water emulsion of claim 26, wherein the derived polyethylene glycol or polyethylene glycol-binding lipid is methoxy polyethylene glycol having a molecular weight of about 1000 to 6000. a) 50% (w / v) or less of a lipophilic core, which is a lipophilic derivative or radiopharmaceutical of a pharmaceutically inert fat or oil and a lipophilic contrast agent or radiopharmaceutical or water soluble contrast agent of natural, synthetic or semi-synthetic origin; b) up to 10% (w / v) phospholipid emulsifier; c) up to about 5% (w / v) cholesterol; d) up to 5% (w / v) polyethylene glycol derivatives of derived polyethylene glycol or phospholipids; d) up to 5% osmotic modifier (w / v); e) optionally 1% or less antioxidant; f) Oil-in-water emulsion comprising the rest water suitable for parenteral administration. 31. The oil-in-water emulsion of claim 30, wherein the lipophilic contrast agent or radiopharmaceutical or lipophilic derivative or radiopharmaceutical of the water soluble contrast agent is a polyhalogenated triglyceride. 31. The oil-in-water emulsion of claim 30, wherein the lipophilic contrast agent or radiopharmaceutical or lipophilic derivative or radiopharmaceutical of the water soluble contrast agent is an aliphatic ester of a water soluble contrast agent. 33. The oil-in-water emulsion according to claim 32, wherein the aliphatic ester of the water-soluble contrast agent is selected from the group consisting of aliphatic esters of ipananoic acid, ditrizoic acid and acetrizoic acid. 34. The oil-in-water emulsion according to claim 33, wherein the aliphatic ester is selected from the group consisting of ethyl iphananoate and butyl iphananoate. a) 10% to 50% of pharmaceutically inert triglycerides and polyhalogenated triglycerides having a molar ratio of pharmaceutically inert triglycerides to polyhalogenated triglycerides from 0.1: 1 to 2: 1 (w / w) v); b) about 9.9% (w / v) or less of phospholipid including dioleoylphosphatidylcholine and MPEG-linked phospholipids; c) no more than 4.8% (w / v) in the molar ratio of cholesterol to total phospholipids ranging from 0.05 to 0.70; d) 5% cholesterol (w / v); e) 0.1-0.6% of α-tocopherol; And f) Oil-in-water emulsion comprising water as the remainder of the emulsion, the emulsion having an average particle diameter of an oil phase of 50 to 150 nm and at least 98% of the particles being 50 to 250 nm. 36. The oil-in-water emulsion of claim 35, wherein the molar ratio of pharmaceutically inert triglyceride to polyhalogenated triglyceride is 1: 1. 36. The oil-in-water emulsion according to claim 35, wherein the amount of cholesterol is in the range of 0.4 to 0.5% (w / v). 38. The oil-in-water emulsion of claim 37, wherein the molar ratio of cholesterol to total phospholipid is 0.4. 36. The arylated arylaliphatic triglyceride homologue of claim 35 wherein the polyhalogenated triglyceride is a 1,3-disubstituted triglyceride backbone having a 3-substituted 2,4,6-triiodophenyl aliphatic chain or a monoiodophenyl aliphatic chain. Oil-in-water emulsion, a lipophilic diagnostic agent selected from the group consisting of: 40. The oil-in-water emulsion of claim 39, wherein the polyhalogenated triglyceride is 2-oleoylglycerol-1,3-bis [7- (3-amino-2,4,6-triyodophenyl) heptanoate]. 40. The oil-in-water emulsion of claim 39, wherein the polyhalogenated triglyceride is 2-oleoylglycerol-1,3-bis [4- (3-amino-2,4,6-triyodophenyl) butanoate]. 32. The oil-in-water oil according to claim 31, wherein the polyhalogenated triglyceride is a 1,2,3-trisubstituted triglyceride skeleton having a 3-substituted 2,4,6-triyodophenyl saturated or unsaturated aliphatic chain or a monoyodophenyl aliphatic chain. Emulsion. 36. The oil-in-water emulsion according to claim 35, wherein the polyhalogenated triglyceride is fluorinated triglyceride. a) administering to the mammal an amount of an imaging phase of the oil-in-water emulsion of claim 35 containing a computed tomography imaging agent; b) performing computed tomography imaging of the site when the amount of imaging of the oil-in-water emulsion reaches the site to be imaged. A biological treatment method requiring treatment comprising administering an oil-in-water emulsion of claim 1 containing a therapeutically active lipophilic agent or a lipophilic derivative of a water-soluble agent. a) administering to the mammal an amount of an imaging phase of the oil-in-water emulsion of claim 35 containing a computed tomography imaging agent; b) performing computed tomography imaging of the site when the amount of imaging of the oil-in-water emulsion reaches the site to be imaged. (a) preblending an oil-in-water emulsion comprising nonpolar lipids, polar lipid emulsifiers and other lipophilic components to form a premixed lipid phase; (b) homogenizing the crude oil-in-water emulsion by homogenizing the premixed lipid phase and the aqueous component; (c) subjecting the oil-in-water emulsion to ultra-high energy mixing to produce a fine oil-in-water emulsion having an average particle diameter of 50 to 150 nm in oil phase and at least 98% of the particles are 250 nm Process for preparing oil-in-water emulsion. 48. The method of claim 47, further comprising introducing a fine oil-in-water emulsion with subsequent filtration.