Design and Development of a Proniosomal Transdermal Drug Delivery System for Captopril

Purpose: The aim of the study was to develop a proniosomal carrier system for captopril for the treatment of hypertension that is capable of efficiently delivering entrapped drug over an extended period of time.
Method: The potential of proniosomes as a transdermal drug delivery system for captopril was investigated by encapsulating the drug in various formulations of proniosomal gel composed of various ratios of sorbitan fatty acid esters, cholesterol, lecithin prepared by coacervation-phase separation method. The formulated systems were characterized in vitro for size, vesicle count, drug entrapment, drug release profiles and vesicular stability at different storage conditions. Stability studies for proniosomal gel were carried out for 4 weeks.
Results: The method of proniosome loading resulted in an encapsulation yield of 66.7 - 78.7%. Proniosomes were characterised by transmission electron microscopy. In vitro studies showed prolonged release of entrapped captopril. At refrigerated conditions, higher drug retention was observed.
Conclusion: It is evident from this study that proniosomes are a promising prolonged delivery system for captopril and have reasonably good stability characteristics.

Keywords
Proniosomes, Captopril, In vitro release, Transdermal delivery, Stability studies.