Proniosomes as a Carrier System for Transdermal Delivery of Clozapine.

The current study aimed to formulate the clozapine (CLZ) loaded proniosomal gel (PN) and evaluate it's release, permeation and gel properties. CLZ is a BCS class II drug with low bioavailability of 27% and severe adverse drug reactions (ADRs) due to frequent dosing. Proniosomes offer a versatile pro-vesicular approach with potential in transdermal drug delivery. PN-CLZ gel was prepared by the coacervation phase separation method utilizing span-60, cholesterol and lecithin. Optimization of PN gel was done by hit & trial method and the formulations were characterized for particle size, entrapment efficiency (EE), polydispersity index (PDI) and zeta potential (ZP). The optimized formulation had the highest entrapment efficiency of 90% and the average particle size of approx. 325 nm. PDI reflected homogeneity in the formulation. ZP was -59.76 mV, high enough to indicate a stable formulation. The release studies manifested a sustained release behavior of clozapine from the proniosomal gel. The permeation showed noteworthy permeation of the drug through stratum corneum with a steady state flux of 18.26 ug/cm/hr. The optimized gel was analyzed for pH, spreadability, bioadhesion and rheology. The results suggested that clozapine could be effectively loaded into proniosomal gel for administration through skin.