Design, Formulation and Evaluation of Transdermal Drug Delivery System of Budesonide

Budesonide is a highly potent synthetic, nonhalogenated corticosteroid. The mechanism of action of corticosteroids in allergic rhinitis remains unknown, but may involve reductions in number of various mediator cells such as basophils, eosinophils, T-helper cells, mast cells, and neutrophils. In the nasal mucosa, nasal reactivity to allergens, and release of inflammatory mediators and proteolytic enzymes. Budesonide is very effective and quikly acting as it is rapidly and almost completely absorbed after oral administration, but has poor systemic availability (about 10%) due to extensive first-pass metabolism in the liver, mainly by the cytochrome P450 isoenzyme CYP3A4.. The major metabolites, 6-β- hydroxybudesonide and 16-α-hydroxyprednisolone have less than 1% of the glucocorticoid activity of unchanged drug with a terminal half-life of about 2 - 4 hours. Polymeric films containing Eudragit RL 100: Eudragit RS: drug (7:3:1, 7: 2:1) and Ethyl cellulose: PVP: drug (7:3:1, 7:2:1) were selected for transdermal administration based on evaluation studies. These polymeric films were prepared by mercury substrate method employing PEG-400 as plasticizer. Two different penetration enhancers Urea and Dimethyl sulphoxide (DMSO) were employed in the study. The patches in each group were uniform in drug content, thickness. In Vitro drug permeation, moisture absorption and WVTR studies were carried out on these test patches. It was found that at all humidity condition the absorption increases which were linear to the moisture absorbed. In PVA and EUDRAGIT RL 100 patches the water vapor transmission rate was found to be higher at 75% RH, RT conditions. Therefore at both % RH, RT condition the PVA and EUDRAGIT RL 100 patches provides the best resistance to water vapor. Therefore, when applied to animals (in further studies) these patches may provide more occlusion to water vapor loss from skin thus making atmosphere beneath the skin more humid that aid in drug permeation.