Bioavailability of indomethacin in liposomes.

The research concerned the influence of the liposomally-entrapped indomethacin on its absorption after intragastric administration to rats. It was found that the indomethacin entrapped in liposomes has a favorable influence on the bioavailability in comparison to sole indomethacin suspension.

[Bioavailability of griseofulvin in the form of liposomes]. / Bioverfügbarkeit von Griseofulvin in Form von Liposomen.

Liposomes containing griseofulvin have been prepared by shaking method. Lecithin and cholesterol were used to compose phospholipid bilayer of liposomes. The suspension of liposomes in 0.9% sodium chloride and the suspension of griseofulvin in 0.25% iostonic methylcellulose solution were used in the comparative study in vivo. Both suspensions were administered intragastricly to rats. Parameters of bioavailability have been found on the basis of the changes in griseofulvin plasma concentrations versus time. Intragastric administration of griseofulvin in liposomes suspension demonstrates ca. 40% higher Cmax and AUC when compared to these of griseofulvin suspension which indicates a better bioavailability.

[The effect of entrapment of procaine hydrochloride in liposomes on its local anesthetic action]. / Zum Einfluss des Einschlusses von Procainhydrochlorid in Liposomen auf die lokalanästhetische Wirkung.

The study has shown the effect of liposomally entrapped procaine hydrochloride on local anaesthesia and its intensity after intradermal administration. The experiments of anaesthetic infiltration have been carried out on guinea pig skin applying mechanical stimulus. Liposomes were prepared by the shaking method followed by suspending in phosphate buffer pH 7.2, 0.5% methylcellulose in phosphate buffer or 5% glucose solution. The results of the study were compared with those of procaine hydrochloride in analogous solutions. The study has shown significant influence of liposomally entrapped procaine hydrochloride on the prolongation of local anaesthesia and its intensity. It has also been shown that local anaesthesia was influenced by the composition of the solutions in which liposomes were suspended. The longest effect (55 min) has been observed after administration of liposomes in phosphate buffer with methylcellulose.

[The bioavailability of dipyridamole in the form of liposomes]. / Bioverfügbarkeit von Dipyridamol in Form von Liposomen.

Liposomes containing dipyridamole have been prepared by evaporating-shaking method. Phospholipid bilayer consisted of lecithin and cholesterol in three varying molar rations: 5:2, 7:2, 10:2. According to lipid layer composition the obtained liposomes varied in size and amount of dipyridamole entrapped. The suspension of liposomes in 0.9% sodium chloride prepared with lecithin and cholesterol in molar ratio 7:2 was chosen to the study in vivo. A suspension of dipyridamole in 0.9% sodium chloride was used comparatively. Particle size of dipyridamole was similar to that of liposomes with entrapped substance. Both suspensions were administrated to guinea pigs orally or intraperitoneally. The study has shown that liposomally-entrapped dipyridamole has essential and advantageous effect on its absorption after oral or intraperitoneal administration when compared with dipyridamole itself. The best bioavailability has been demonstrated by the suspension of liposomes after intraperitoneal administration.

[Liposomes as drug vehicles in percutaneous therapy]. / Liposomen als Wirkstoffträger in der percutanen Therapie.

Liposomes may be utilized as favourable drug-carriers also in ointments. The experiments on men have demonstrated that triamcinolone entrapped in liposomes consisted of egg lecithin and cholesterol, put on the forearm skin in form of the ointment, was absorbed in three times greater amount than from the ordinary ointment.

In vitro study of (2S, 2'S) N,N'-dimethyl-N, N'-bis [1(3', 4', 5'-trimethoxybenzoyloxy) butyl-2] ethylenediamine salts and their bioavailability.

The aim of this study was to improve the oral dosage form of the title compound. The study include base, dihydrochloride and dimaleate. In vitro study was carried out on rat intestine, in vivo on rats and rabbits. The low absorption of the M-71 salts has been shown in both in vitro and in vivo studies. To increase bioavailability in men the tablets or enteric coated tablets should be made according to the results of clinical trials.

The attempts of retarding the release of nitroglycerin from granules.

The effect of Eudragit S, RL, or RS and ethylcellulose on the rate of release of nitroglycerin from granules has been studied. It was shown that Eudragits (acryl resins) and ethylcellulose decrease the rate of release of nitroglycerin from granules. The retarding effect depends on the amount and the kind of a retarding agent. Eudragit RS was the most effective one.

The study of the bioavailability of coated acetylsalicylic acid in suppositories after rectal administration.

The rate of release of acetylsalicylic acid (ASA) coated and uncoated from suppositories in vitro, and the bioavailability of ASA in vivo were examined. The coating reduces the rate of release of activite drug from suppositories. In vivo the coating delays the obtention of the maximum concentration of salicylates in urine, but doesn't have any essential effect on cummulative amount of salicylates in urine.