Formulation by design based risperidone nano soft lipid vesicle as a new strategy for enhanced transdermal drug delivery: In-vitro characterization, and in-vivo appraisal.

The present study was designed to formulate and optimize transdermal risperidone soft lipid vesicles. The formulation optimized with phospholipid, safranal and ethanol were incorporated as permeation and absorption enhancers. The optimized risperidone soft lipid vesicle was further evaluated for skin irritation study, in-vivo pharmacokinetic study and locomotor activity. Three factor three level Box-Behnken design (BBD) was used to statistically optimize soft lipid vesicle using safranal (A), ethanol (B)and phospholipid (C) as independent variable, while their effect was observed for vesicle size (Y), entrapment efficiency (Y) and flux (Y). The optimized risperidone soft lipid vesicle (Ris-opt) showed nanometric vesicle size, high entrapment efficiency and marked enhancement in transdermal flux. The extent of absorption from Ris-opt was greater when compared to oral suspension with relative bioavailability of 177%. The histopathological evaluation revealed developed formulation did not showed skin irritation compared to standard irritant. The significant findings presented here encourage further studies with risperidone soft lipid vesicles for treatment of schizophrenia.