Alteration of Skin Hydration and its Barrier Function by Vehicle and Permeation Enhancers: A Study using TGA, FTIR, TEWL and Drug Permeation as Markers

Nehicles andperineation enhancers (I'Es) used in transdermal drug delivery (TDD) ofa drug can qffect skin hYdration, integrill; andpernleation ofthe solute administered. This investigation was designed to study the effect ofthe most commonlY used vehicles and PEs on rat skin hi,dration, barrier./unction andpermeation ofan amphiphilic drug, imipramine Indrochloride (LUH). An arrqv ofit,ell-establishedlechi7iqtie.v were usedto confirm thefindings ofthe studv Thermograipimetric anahsis (TGA) and Fourier transform infrared (FTIR) spectroscopy were used to determine changes in skin 1wdration. Alteration of the stratum corneum (SQ structure was investigated using FTIR studies. To monitor the harrierfimclion alteration, transepidermal water loss (TE WL) measurement and permeation studies were petformed. Out- findings indicate that with hYdration, there, was an increase