The objective of the present study is to explore the efficient chemical penetration enhancer among the various enhancers available in overcoming the stratum corneum barrier in transdermal delivery of Alfuzosin hydrochloride (AH). The different enhancers were incorporated in 2% Carbopol gel which was selected as a control and evaluated by in vitro diffusion studies through dialysis membrane and permeation through the rat abdominal skin using Keshary-Chien diffusion cells. All the enhancers increased the release rate through the dialysis membrane when compared with control except oleic acid which decreased the release rate but showed maximum solubility of the drug. Among the various enhancers Transcutol 20% and tween-20 (2%) showed the highest cumulative amount (Q24) of 702.28 ± 6.97？μg/cm2 and 702.74 ± 7.49？μg/cm2, respectively. A flux rate of 31.08 ± 0.21？μg/cm2/hr by Transcutol 20% and 30.38 ± 0.18？μg/cm2/hr by tween-20 (2%) was obtained. Transcutol 20% showed decreased lag time of 0.13 ± 0.05？hr. The lowest skin content of 342.33 ± 5.30？μg/gm was seen with oleic acid 2.5%. Maximum enhancement of flux by 3.94-fold was obtained with transcutol 20%. Primary skin irritation studies were performed with rabbit. Histopathological studies of transcutol 20% showed marked changes such as degeneration and infiltration of mononuclear cells in dermis indicating the effect of transcutol on the skin. Among the different enhancers transcutol is efficient in enhancing transdermal delivery of AH. 1. Introduction Alfuzosin hydrochloride (AH), the -adrenoreceptor antagonist, is used for treating benign prostatic hyperplasia. It is indicated for long-term therapy in place of surgery. It undergoes extensive first pass metabolism, has a bioavailability of 60%, half-life (3–5 hour), (1.6), molecular weight (425.9 Daltons) and dose (10？mg per day) [1]. Its physicochemical properties suggest that transdermal drug delivery would be beneficial, but the challenging aspect in transdermal delivery route is permeation through stratum corneum [2]. Several technological approaches have been attempted to overcome this challenge. They are physical approaches, chemical approaches, formulation approaches, and so forth [3]. Chemical approach is the most widely implemented. Chemical enhancers based on their physico-chemical properties enhance permeation through the skin by different mechanisms such as creating diffusion pathways for drug by extracting lipids from the skin, disrupting highly ordered lipid lamellae by partitioning into lipid bilayers, fluidization of lipids, and enhancing the
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