Abstract

DESIGN, DEVELOPMENT AND IN VITRO INVESTIGATION OF WATER IN OIL NANOEMULSION FOR TRANSDERMAL DELIVERY

Sonal Setya*, Poornima Negi,Dr. B.K.Razdan,Dr.Sushama Talegaonkar

ABSTRACT

The objective of the study was to investigate the potential of w/o nanoemulsion prepared by high energy method for transdermal delivery of hydrophilic drug. Tacrine hydrochloride was selected as a model drug for the study. Coarse emulsions prepared by oil phase titration method were subjected to sonication for 30 minutes to produce nanosized droplets. In vitro skin permeation of optimized nanoemulsions showed significant increase (p < 0.05) in steady state flux (Jss) and permeability coefficient as compared to controls. Maximum value of permeation flux (6.172±2.94 μg/cm2/h) was obtained with formulation TD7 comprising of 7 mg of tacrine hydrochloride dissolved in 10% w/w of distilled water, 30% w/w surfactant mixture (Labrafil M and Transcutol P in ratio of 1:4) and 60 % Capryol 90 as continuous phase. Effective permeation of w/o nanoemulsion is attributed to its components which themselves acted as permeation enhancers. Optimized formulation showed least droplet size of 156.4 ±0.48 nm with poly dispersity index of 0.36 ± 0.4. Reduced droplet size as a result of sonication was directly related to the permeation profile of nanoemulsions. TD7 had pH of 6.1 ± 0.28 and viscosity of 20.24± 0.24 cps. The refractive index was found to be 1.412 ± 0.22. Transmission electron microscopy & scanning electron microscopy images showed spherical shaped aqueous droplets dispersed in oily phase with size ranging from 97 to 267 nm. Optimized nanoemulsion was converted to nanoemulsion gel by using ethyl cellulose (20cps) as thickening agent. Slow release of drug was due to w/o nanoemulsion acting as a reservoir. Nanoemulsion gel permeation was 4.4 times more than hydrogel of tacrine hydrochloride. (p < 0.05) Results suggest that w/o nanoemulsion prepared by sonication has a promising role in transdermal delivery of water soluble drugs.

Keywords: w/o nanoemulsion, sonication, tacrine hydrochloride, nanoemulsion gel, permeation.