Formulation of Transdermal Drug Delivery System: Matrix Type, and Selection of Polymer- Their Evaluation

Goatskin is used instead of rat-skin to study the permeation and the results are compared. The percentage of permeation is double in goatskin. We have five different oils to study, how they influence permeation and all of them have improved permeation when used on goatskin. To analyze further two parameters-percentage and rate of permeation are used. When these five oils are used with salicyclic acid on goatskin the following results are obtained. The percentage of permeation is as follows [Caraway oil (48%) > Lemon oil (36%) > Peppermint oil (29%) > Lemon Grass oil (22%) > Citronella oil (19%)]. The caraway oil has the highest percentage of permeation whereas citronella oil has the lowest percentage of permeation. Caraway oil has three times more permeation than that of citronella oil. The selection of polymer for the formulation of TDDS was done basing on a comparative study of five polymers and their various combinations using such parameters as uniformity of weight, thickness and content and percentage and rate of diffusion counted. Results show that methylcellulose and hydroxy propyl methyl cellulose record more control release of salicyclic acid than the other polymers. Except HPMC all other polymers follow zero order kinematics. Basing on this experimental evidence transdermal patch of salicyclic acid was formed with HPMC, MC polymer incombination with caraway oil has permeating enhancer and evaluated using goatskin. Comparative study shows that there is two fold increases in the percentage of permeation.