[Preparation and structural determination of lyotropic lamellar liquid crystalline systems of pharmaceutical importance]].

Lamellar lyotropic liquid crystalline systems are thermodynamically stable, optically isotropic continuous compositions composed of particles of a few nanometeres in diameter which are formed spontaneously or with a low energy input in the definite proportions of the given components [8, 27]. New possibilities for the development of controlled drug delivery systems are inherent in these systems in consequence of their stability and special, skin friendly structure [3]. The present aim was to formulate and study two- or multicomponent compositions with a relatively low surfactant content, composed of materials official in the pharmacopoeia and suitable for therapeutic purposes.

Structure and drug release of lamellar liquid crystals containing glycerol.

Lamellar lyotropic liquid crystalline (LLC) systems are thermodynamically stable, optically isotropic systems, which are formed with low energy input. New possibilities for the development of controlled drug delivery systems are inherent in these systems due to their stability and special skin-similarly structure. The present aim was to formulate multicomponent LLC systems with a relatively low surfactant content, composed of materials official in the European Pharmacopoeia 4th.

Incidence of hepatitis B surface antigen (HBsAg) in some areas of Romania.

The incidence of HBsAg in several areas of Romania was studied by 253,460 routine determinations performed from 1973 to 1975. HBsAg incidence was of 1.5% in blood donors and reached the highest value in acute viral hepatitis patients undifferentiated according to the clinical form.

Hepatitis B antibodies in hospital personnel.

Sera from 544 hospital personnel members with different degrees of exposure to the agent of hepatitis B were tested for HB8Ag and anti-HB8 by counterelectrophoresis, radioimmunoassay and passive hemagglutination. The laboratory staff and persons having direct contact with patients exhibited a significantly higher prevalence of anti-HB8 (16.2%) as compared with the other groups: administrative staff (4.

[Distribution of subtypes of viral hepatitis B antigen in areas of Rumania].

The results of subtyping the B antigen in 551 sera from patients with viral hepatitis, chronic evolutive hepatitis and cirrhosis, chronic carriers, donors and healthy subjects, were confirmed as positive HBAg by diffusion in agar, counterelectrophoresis and radioimmunology, and characterized by the d-y and w-r determinants by rheophoresis. The high incidence of the y determinant in all nine counties investigated probably reflects the prevalence of this serotype in Romania, recalling the distribution of subtypes observed in the south of Europe.