Formulation and evaluation of liposomes of natural phospholipids for the treatment of inflammatory conditions

Abstract

Liposomes is an attractive therapeutic strategy to overcome the hindrances presented by the conventional therapies. Liposomes composed of natural and/or synthetic phospholipids differ in phase transition temperatures which determines most of the properties associated with liposomal drug delivery system. In the present study we attempted the formulation and evaluation of conventional liposomes of anti-inflammatory agent, diclofenac sodium and phospholipase inhibitor, cilostazol for the treatment of anti-inflammatory conditions.Considering the impact of components on the physical and functional properties, liposomes were prepared using phospholipids of natural [phospholipon 90H (LDH-1 to LDH-3); phospholipon 90 (LD90-1 to LD90-3); egg yolk phosphatidylcholine (LDE-1 to LDE-3)] by thin film hydration method. The spherical morphology of vesicular liposomes was observed under microscope with average mean diameter ranging between 100-200 nm. The nanometric size and spherical shape of vesicular liposomes was confirmed by the TEM analysis. Zeta potential values of all the formulations were found to be negative. The increase in phospholipid concentration increased the surface charge negativity.Phospholipid content in liposomal formulations was found to be increased with increase in cholesterol concentration. The extent of ex vivo permeation of liposomal formulation found to be dependent on size of vesicle drug release decreases with increased cholesterol. The phospholipid/cholesterol at molar ratio of 2:1 (with 33.3 % cholesterol content) was found to be most flexible formulation with acceptable characteristics and allowed fastest drug release among the tested formulation.