Enhanced transdermal delivery of an anti-hypertensive agent via nanoethosomes: Statistical optimization, characterization and pharmacokinetic assessment

The aim of the current investigation is to develop and statistically optimize nanoethosomes for transdermal valsartan delivery. Box-Behnken experimental design was applied for optimization of nanoethosomes. The Independent variables were phospholipids 90G (X-1), ethanol (X-2), valsartan (X-3) and sonication time (X-4) while entrapment efficiency (Y-1), vesicle size (Y-2) and flux (Y-3) were the dependent variables. The optimized formulation obtained was then tested in rats for an in vivo pharmacokinetic study. Results indicate that the nanoethosomes of valsartan provides better flux, reasonable entrapment efficiency, more effectiveness for transdermal delivery as compared to rigid liposomes. Optimized nanoethosomal formulation with mean particle size is 103 +/- 5.0 nm showed 89.34 +/- 2.54% entrapment efficiency and achieved mean transdermal flux 801.36 +/- 21.45 mu g/cm(2)/h. Nanoethosomes proved significantly superior in terms of, amount of drug permeated in the skin, with an enhancement ratio of 43.38 +/- 1.37 when compared to rigid liposomes. Confocal laser scanning microscopy revealed an enhanced permeation of Rhodamine-Red loaded nanoethosomes to the deeper layers of the skin as compared to conventional liposomes. In vivo pharmacokinetic study of nanoethosomal transdermal therapeutic system showed a significant increase in bioavailability (3.03 times) compared with oral suspension of valsartan. Our results suggest that nanoethosomes are an efficient carrier for transdermal delivery of valsartan. (C) 2013 Elsevier B.V. All rights reserved.