Accession Number : ADA134411

Title :   An Investigation of Membrane-Encapsulated Trypanocides.

Descriptive Note : Annual rept. 16 Jan 79-15 Jan 80,

Corporate Author : WASHINGTON UNIV SEATTLE

Personal Author(s) : Hwang,Karl J

PDF Url : ADA134411

Report Date : 15 Jan 1980

Pagination or Media Count : 28

Abstract : A new method which is capable of entrapping 111 In 3+ in any types of liposomes with an efficiency of 80% about 90% has been developed. There are no differences in the physical properties and biodistribution between the liposomes encapsulating 111 In 3+ by this new loading method and that by the conventional method of encapsulation. Hepatic degradation of sphingomyelin:cholesterol (2/1; M/M) unilamellar liposomes is investigated by the combined approaches of perturbed angular correlation of gamma radiation and kinetic modeling. The hepatic degradation of the SM:CH(2/1; M/M) unilamellar liposomes in vitro at 37 C follows the first order kinetics with a half-life of 3.5 + or - 0.2 hours. However, the rate of the in vivo degradiation of liposomes in the liver of a mouse is found to be 4.3 + or - 0.2 hours. The rate of release of the liposome-encapsulated agent, indium-111, in the liver, is not constant and reaches a maximum at about 8 hours after the administration of liposomes. The potential carrier application of serum protein-lipid vesicles is found to be limited. However, the SM:CH (2/1; M/M) unilamellar liposomes is found to be an excellent carrier with a blood clearance half-life of about 16.5 hours. This is by far the longest clearance time ever reported for liposomes of natural sources.

Descriptors :   *Trypanocides, *Quinolines, Blood circulation, Physical properties, Biological absorption, Kinetics, Degradation, Cells(Biology), Transport properties, Encapsulation, Liver, Mice, Tissues(Biology), Distribution, Tables(Data), Labeled substances, Hydroxyl radicals

Subject Categories : Medicine and Medical Research
      Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE