The effect of formulation factors on the release of oxybutynin hydrochloride from transdermal polymeric patches

The aim of the present study was to formulate oxybutynin in a relatively stable and more acceptable and bioavailable dosage form. Gels and patches were formulated according to the standard methods. The prepared formulations were tested for their hygroscopicity, content uniformity, weight variation and tensile strength. Also the release profile and the stability of patches were determined. The results showed that the amount of humidity absorbed by and F19 was 9.21±0.199 and 9.51±0.306 respectively. The results of tensile strength measurement showed 1.97 and 2.55 g. cm-2 for formulation F5 and F19, respectively. Statistical analysis showed that F5 was significantly more flexible than F19. Regarding their content uniformity, there was the maximum value for both formulations and no significant difference was shown. The results presented in the present study suggest that transdermal patches containing oxybutynin HCl may produce acceptable systemic concentration for therapeutic effect.