Gemcitabine hydrochloride (GEM) is a potential anticancer drug but it has certain limitations like short biological half life, low therapeutic index, rapid metabolism to the inactive metabolite & non-selectivity towards cancer cells resulting into common side effects of chemotherapy. The purpose of the study was formulation and evaluation of GEM loaded PEGylated liposomes to increase the residence time in systemic circulation & study its in-vivo performance. The liposomes were prepared by thin film hydration method using various phospholipids and were characterized for various parameters. The conventional & PEGylated liposomes were compared with free drug for its in-vivo performance, blood toxicity & in-vitro anticancer activity. Optimized formulations were subjected to stability studies for up to 2 months. Stable GEM loaded PEGylated liposomes having size and entrapment efficiency 400-800nm and 45-52% respectively and was obtained. In-vitro drug dissolution studies showed sustained release confirming long circulation of PEGylated liposomes. Blood toxicity studies reflected reduced toxicity of formulations than free drug. The pharmacokinetic parameters have demonstrated increased plasma half life of PEGylated formulation than conventional and free drug. In vitro anticancer activity in human lung cell lines showed many fold increase in the cyto-toxicity compared to pure drug. The study demonstrates efficient tumour targeting of GEM loaded PEGylated liposomes due to improved pharmacokinetics and residence time, reduced blood toxicity and enhanced in-vitro anticancer activity
