HPMC & EC based formulation and in vitro & ex vivo evaluation of atorvastatin transdermal patch
Sujatha P Muchalambe, A Geethalakshmi, Amar Kumar Gupta
Transdermal therapeutic systems have been designed to provide controlled continuous delivery of drugs via the skin to the systemic circulation. Advantages of transdermal delivery include convenience, comfort, by-pass the first phase hepatic metabolism, and control over drug absorption. Atorvastatin undergoes high intestinal clearance and first-pass metabolism, which is the main cause for the low systemic availability (30%). Food has been shown to reduce the rate and extent of atorvastatin absorption. Administration of atorvastatin with food produces a 25% reduction in Cmax (rate of absorption) and a 9% reduction in AUC (extent of absorption). In present work was designed to develop suitable transdermal matrix type of Atorvastatin calcium, using Hydroxypropyl methylcellulose (HPMC), Eudragit RS 100 and ethyl cellulose (EC) with PEG 400 (as plasticizer) and propylene glycol (as penetration enhancer). The solvent casting technique was employed for the preparation of Atorvastatin calcium transdermal patches. The dry films were evaluated for weight variation, thickness uniformity, moisture content, moisture uptake, folding endurance and % drug content. In-vitro release studies were performed using Franz’s diffusion cell and permeation studies were carried out by using rat skin. The concentration of diffused drug was measured using UV- visible spectrophotometer at λ max 246.2 nm. FT-IR studies revealed that the drug and polymer were compatible with each other and all the batches prepared and evaluated, F1, F4 and F5 showed promising results. It was concluded that HPMC and ethyl cellulose are useful in formulating sustained release Atorvastatin transdermal patches.
Keywords: Transdermal Drug Delivery, Atorvastatin Calcium, HPMC, EC, Eudragit, PEG 400.