Effect Of Plasticizers On The Permeability And Mechanical Properties Of Eudragit Films For Transdermal Application
The present investigation was taken up to prepare and evaluate Eudragit RS100 films as rate controlling membrane for transdermal use and to study the effect of different concentrations of various plasticizers on the permeability and mechanical properties. Drug free films of Eudragit RS100 were prepared by the casting method on mercury surface employing chloroform as a solvent and dibutyl phthalate (DBP) and polyethylene glycol-400 (PEG) as plasticizers. These films were evaluated for thickness uniformity, tensile strength, percentage of elongation and water vapor transmission. Permeability characters of these films were studied using verapamil hydrochloride (VPH) as a model drug. The thickness of the films was found to be uniform. Tensile strength of the films prepared using DBP as plasticizer was high compared to the films plasticized with PEG. Water vapor transmission and drug diffusion through films followed a pattern closed to zero order type and it was decreased with increase in the film thickness. Films plasticized with PEG showed higher permeability to verapamil hydrochloride. The permeability of the drug was decreased as the concentration of dibutyl phthalate was increased. Whereas increase in the concentration of PEG enhanced the permeability characteristics of the films.