Design and evaluation of liposomal delivery system for L-Asparaginese

Despite of its effective anti-tumour activity,L-Asparaginase has limited clinical application due to the high rate of clinical hypersensitivity. In an attempt to develop a liposomal drug delivery for L-Asparaginase, enzyme loaded liposomes were formulated using soy lecithin, cholesterol and charge inducers by thin film hydration method. The effect of various components of the liposomes including the concentration of lecithin and cholesterol with or without the charge inducers on the entrapment efficiency and short term invitro cytotoxicity study was systematically investigated. The average particle sizes of the vesicles were found to be 43.2, 35.6 and 65.8 µm respectively for neutral, positive and negative liposomes. The percentage of drug loading was found to be 1.95, 2.39 and 2.35 % respectively for neutral, positive and negative liposomes.The invitro release study of L-Asparaginase was carried out using normal saline as dissolution medium and the release was found to be 86.88, 78.29 and 82.04 % respectively for neutral, positive and negative liposomes. The release of L-Asparaginase from liposomes was followed first order kinetics obeying non-Fickian diffusion. A short term cytotoxicity study was carried out using Ehrlich Ascites Carcinoma cells (EAC cells) which revealed that the cytotoxicity concentration CTC50 for pure drug was found to be 64 mcg as compared to liposomal formulation of 50 mcg.