Preparation and Evaluation of Mefenamic Acid Transdermal Patches Prepared from Pressure Sensitive Adhesive

Abstract

The pressure sensitive adhesive is interesting to apply in pharmaceutical and medical products. It composed of STR 5L block rubber which has high uniformity and very low impurity. Thus, it was used to prepare the transdermal patches for mefenamic acid delivery. The mefenamic acid powder was loaded in pure STR 5L block rubber and pressure sensitive adhesive. The pressure sensitive adhesive was the STR 5L block rubber mixed with hydroxyethyl cellulose and white oil which were used as tackifier and softener, respectively. The preparation of mefenamic acid loaded in transdermal patches were crushed by melt blending technique with two-roll mill machine. The mefenamic acid could be mixed into pure STR 5L block rubber and pressure sensitive adhesive to be the homogeneous transdermal patches. The percentages of moisture uptake and swelling ratio were less than 5% and 15%, respectively. The mefenamic acid was entrapped in the range of 75-90%. However, the content of mefenamic acid from transdermal patches was a low cumulative release (less than 60% of cumulative drug release). Therefore, this preparation of mefenamic acid loaded in transdermal patches might be developed to increase the release of mefenamic acid from transdermal patches in further study.