The elimination peculiarities of perfluorocarbon emulsions stabilized with egg yolk phospholipid.

In order to examine the elimination rate of Perfluorodecalin (FDC) emulsions stabilized with different emulsifiers--yolk phospholipid (EYP) and procsanol P-268 (analog of Pluronic F-68)--we performed controlled trials on excretion of FDC in exhaled air, elimination from blood and accumulation in the liver. Adult Wistar rats were injected intravenously with FDC emulsions stabilized with different emulsifiers at a dose of 11.5 g FDC per kg body weight. The concentration of FDC in blood, exhaled air and liver tissue was examined by means of the gas chromatography method. The circulation time in blood for the emulsion stabilized with EYP was much longer comparatively to the emulsion containing the synthetic emulsifier procsanol P-268. The injection of EYP dispersions prolonged the circulation time of lipid-stabilised FDC emulsions. The rate of PFC elimination in exhaled air from such an emulsion and the rate of its accumulation in liver during the initial period after injection are reduced compared to the procsanol-stabilized emulsion. These data are interpreted as the result of a reduction of phagocytic activity of blood monocytes toward the lipid-coated particles of the emulsion. The circulation time of PFC emulsion can be prolonged by using lipid emulsifier and additional injections of EYP dispersion.

Effect of perfluorochemical emulsion on lipoproteins of plasma blood.

The effect of perfluorocarbons (PFC, Perfluorodecalin/Fogalin) on the lipoprotein level in plasma was studied. The PFC emulsion (FCE) was injected i.v. at a dose of 6 g PFC per kg of body weight into male Wistar rats weighing 250-280 g. The lipoproteins were separated by preparative centrifugation. It was found that PFCs influence the metabolism of lipoproteins. The greatest depletion of cholesterol level occurs in the HDL fraction of lipoproteins 3 and 24 hrs after injection. There is no relationship between the level of cholesterol in plasma and cholesterol lipoproteins. The content in lipoproteins, however, amounts to half the level of the cholesterol of plasma 72 hrs after injection. Based on these facts it is possible to conclude that when PFCs leave the cells of organs, they are carmed in the blood stream as a complex which contains at least PFCs, cholesterol and triglycerides.

Effect of lipid absorption by perfluorochemical emulsions in the bloodstream and perspectives of its clinical application.

Studies concerning lipid absorption by perfluorochemical particles (PFC) during circulation in the blood stream have been reported in experimental animals. We studied the cholesterol absorption from high density lipoproteins (rats) and erythrocyte membrane [1] and composition of the absorbed lipids [2]. The aim of present investigation is to clarify the influence of the PFC chemical structure and synthetic emulsifier on the composition of the absorbed lipids. The perspectives of clinical application of the effect of the lipid absorption by PFC particles is discussed.

Some aspects of perfluorochemical emulsion's interaction with blood.

FDC/FTPA (7:3) emulsions stabilized by procsanol (Emulsion 1) and by procsanol with yolk phospholipids (Emulsion 2) were incubated with the donor plasma. After the incubation during 6 hours of Emulsions 1 and 2 with plasma the 36% and 50% decrease of the cholesterol content in plasma was found. Analysis of the lipid content of lipoproteins after the Emulsion 2 administration to rats (2.5 ml/100 g of weight) revealed the 50% decrease of the cholesterol amount in the HDL fraction at 3 and 24 hours posttransfusion. The ratio cholesterol/total phospholipids in the erythrocyte membrane diminished up to 50% as well. The equal degree of the cholesterol adsorption by emulsion from plasma, HDL of rats and erythrocyte membrane is an evidence of nonspecific interaction of PFC particles with the blood components containing cholesterol.

[Perfusion protection of ischemic liver using perfluorocarbon emulsion]. / Perfuzionnaia zashchita ishemizirovannoi pecheni s ispol'zovaniem perftorugliarodnoi émul'sii.

Several concentrations of Fluorocarbon emulsion as means for anti-ischemic protection of the liver were studied in experiments on 47 rabbits with hypothermic perfusion of isolated liver exposed to 90 minute ischaemia. the best concentration of Fluorocarbon emulsion for perfusion of isolated liver was 12%.

[Various aspects of production of a therapeutic form of liposomal cytarabine]. / Nekotorye aspekty sozdaniia lekarstvennoi formy liposomal'nogo preparata tsitarabina.

In the process of preparation of the liposomal cytostatic drug cytarabine for intravenous injection, the influences of the lipid composition of liposomes, the cryoprotector, and the technique of its administration on the liposome intactness were studied by HPLC. It was shown, that under certain conditions the use of definite components allows for preparing a dosage form of lyophylized sterile liposomal cytarabine capable of being stored for a year.

[Effect of lipid emulsifiers on the properties of organoperfluorine emulsions]. / Vliianie lipidnykh émul'gatorov na svoistva émul'sii perftor- organicheskikh soedinenii.

The preparation and application of a new type of organoperfluorine (OPF) emulsions with lipids serving as emulsifiers, their biological and physicochemical properties are discussed. The first-generation emulsions with the nonionic emulsifier, ethylene and propylene oxide blockpolymer, were found to be complementary active and to affect the system's biological properties. Interactions between OPF and phospholipids are analysed. The compositions of the new type OPF emulsions are given, of which perfluoroctyl bromide and perfluoromethyl adamantine emulsions are shown to be currently of most interest, since they are stable at room temperature and exhibit somewhat superior physicochemical and biological parameters. A conclusion is derived that the developed lipid-based OPF emulsions have good clinical prospects.

[Anti-ischemic protection of the liver using perfluorocarbon emulsion]. / Protivoishemicheskaia zashchita pecheni s primenenium perftoruglerodnoi émul'sii.

Anti-ischemic effectiveness of a Soviet perfluorocarbon emulsion (PFE) was studied in 43 experiments on rabbits with 90-min constriction of the hepatoduodenal ligament and under hypothermic perfusion of the liver during ischemia in the open contour. It has been established that PFE perfusion to a great extent promotes the retention of the ischemized liver function.