K K Chakraborty1, S R Naik. 1. Research and Development Division, Hindustan Antibiotics Ltd., Pimpri, Pune, India. kkchakrabor@yahoo.com
Abstract
PURPOSE: The objective of this study was to evaluate therapeutic and haemolytic effects of liposomal preparation derived from proliposome entrapping inclusion complex of amphotericin B (AmB) with the chemically modified beta-cyclodextrin (beta-CD). METHODS: a series of liposomal AmB formulations with varying beta-CD i.e. Hydroxy propyl beta-CD (HPBCD) and Sulfo butyl ether beta-CD (SBEBCD) having similar AmB content (0.5 mg/kg) were prepared and their effect compared with conventional liposomal amphotericin B (L-AmB) and free AmB on erythrocyte lysis and antifungals activity in experimental aspergillosis- and Cryptococcosis- mice model in-vivo. RESULTS: the liposomal AmB - HPBCD and AmB - SBEBCD found to be 6 times less toxic than free AmB or conventional liposomal AmB. Experimental findings indicate that infected animals treated with L-AmB entrapped inclusion complexes significantly reduced CFU values (fungal counts), whereas infected animals treated with conventional liposome or free AmB showed insignificant reduction in CFU. A marked increase in the percent survival was observed in the case of animals treated with liposomal AmB formulation (HPBCD/SBEBCD). Furthermore, the in-vitro toxicity (haemolysis) of the proliposome-based liposomal vesicles (PBLV) entrapped AmB-SBEBCD/HPBCD at 37 degrees C was approx. 50% at maximum of the conventional liposomal AmB at a dose of 118 microg/ml as measured after 1 hr. incubation. CONCLUSIONS: the results of these experiments permitted us to conclude that the stabilization of liposome derived from proliposome entrapping inclusion complex of amphotericin B (AmB) with beta-CD could serve an alternative approach to enhance the therapeutic window of AmB in clinical medicine.
PURPOSE: The objective of this study was to evaluate therapeutic and haemolytic effects of liposomal preparation derived from proliposome entrapping inclusion complex of amphotericin B (AmB) with the chemically modified beta-cyclodextrin (beta-CD). METHODS: a series of liposomal AmB formulations with varying beta-CD i.e. Hydroxy propyl beta-CD (HPBCD) and Sulfo butyl ether beta-CD (SBEBCD) having similar AmB content (0.5 mg/kg) were prepared and their effect compared with conventional liposomal amphotericin B (L-AmB) and free AmB on erythrocyte lysis and antifungals activity in experimental aspergillosis- and Cryptococcosis- mice model in-vivo. RESULTS: the liposomal AmB - HPBCD and AmB - SBEBCD found to be 6 times less toxic than free AmB or conventional liposomal AmB. Experimental findings indicate that infected animals treated with L-AmB entrapped inclusion complexes significantly reduced CFU values (fungal counts), whereas infected animals treated with conventional liposome or free AmB showed insignificant reduction in CFU. A marked increase in the percent survival was observed in the case of animals treated with liposomal AmB formulation (HPBCD/SBEBCD). Furthermore, the in-vitro toxicity (haemolysis) of the proliposome-based liposomal vesicles (PBLV) entrapped AmB-SBEBCD/HPBCD at 37 degrees C was approx. 50% at maximum of the conventional liposomal AmB at a dose of 118 microg/ml as measured after 1 hr. incubation. CONCLUSIONS: the results of these experiments permitted us to conclude that the stabilization of liposome derived from proliposome entrapping inclusion complex of amphotericin B (AmB) with beta-CD could serve an alternative approach to enhance the therapeutic window of AmB in clinical medicine.