LASER PHOTOCHEMICAL TARGETING OF LIPOSOME ENCAPSULATED DRUG

Abstract

The aim of the present work was to evaluate in vitro oxytetracyclin drug (as a drug model) release from liposome encapsulated oxytetracylin drug and incorporated a lipophilic photosensitizer hypericin. A brief review on methods of liposome as a drug delivery system was presented. General review on hypericin structure, exited states, photosensitization mechanism and its role in photodynamic therapy was given. Also structure, metabolism ofvitamin-E and its role as an antioxidant function was presented. Four samples of liposomes were prepared and encapsulated oxitetracyclin as a model dtug and incorporated with hypericin as a photosensitizer. Two of these samples incorporated with vitamin-E as an antioxidant. Drug releases was measured befor and after irradiation with the same laser dose. Also liposome stability was measured using DSC and FT-IR for all samples. In the present work, irradiated sample without vitamin-E has higher drug release than irradiated sample with vitamin-E indicating that hypericin released free singlet oxygen which damaged intermolecular bonds which results in drug releases but this release was lower for irradiated sample with vitamin-E indicating that vitamin-E captured free oxygen and hence stabilizing liposomal membrane. While unirradiated sample without hypericin has lower drug release than unirradaited sample with vitamin-E as vitamin-E increases the space between acyl chains. From these results, photo-targeting of liposome encapsulated drug is a promising technique for drug delivery.