LIPOSOMAL DRUG DELIVERY SYSTEM FOR ZIDOVUDINE: DESIGN AND CHARACTERIZATION

Zidovudine is an antiretroviral drug with activity against Human Immunodeficiency Virus (HIV) Type 1.However, only temporary and limited benefits are observed in HIV infected patients treated with zidovudinealone or in combination to decrease viral burden, the rapid development of resistance have limited their longterm ef icacy. Hence, in the present work an attempt is being made to provide for stable drug delivery systemwith or having improved therapeutic index for zidovudine in form of lyophilized liposomes. Liposomes havebeen loaded by zidovudine (AZT) as a model drug using thin film hydration technique for targeted delivery ofthis drug. Four dif erent formulations were prepared with various concentrations of egg phosphatidylcholine(EPC) and dipalmitoyl phosphatidylcholine (DPPC). A series of tests have been carried out to characterize thecarrier vesicles in vitro, including loading parameters, drug release kinetics, particle size distribution, SEManalysis. Liposomes having acceptable loading parameters, released their drug content according to zero-orderkinetics were selected for in vivo tissue distribution study. The AZT-loaded liposomes showed preferential drugtargeting to liver followed by lungs, kidney and spleen. Totally, AZT-loaded liposomes seem to be a promisingdelivery system for targeting the drug to reticuloendothelial system (RES)