Study on Drug Release from 25 Products of NSAIDs for External Use (4 Components) Using the Franz Diffusion Cell

Abstract

Objective: An evaluation index for drug release was measured in 25 currently used non‐steroidal anti‐inflammatory drugs (NSAIDs) for external use (4 components: indomethacin, diclofenac sodium, ketoprofen, and suprofen).

Methods: All release tests were performed using the Franz diffusion cell with phosphate buffered saline (PBS) as the receptor phase and an artificial membrane to maintain uniform measurement conditions.　The receptor phase was collected over time and measured using high performance liquid chromatography (HPLC) to calculate the release rate.　The measurement time points were set over 0-4 h based on clinical use.　Furthermore, the additives were compared among the products.

Results: The release profile of diclofenac sodium was similar among all 8 products.　On the other hand, the release rate of IN‐E (15.0% after 4 h) from indomethacin was higher than that from the other 6 products (6.2-9.1% after 4 h).　The release rate of KE‐D (39.2% after 4 h) from ketoprofen was higher than that from the cream, KE‐C (30.6 % after 4 h).　For suprofen, the release rate of SU‐E from the cream (18.1% after 4 h) was 1.6-1.7‐times higher than that of the other 2 products (10.9-11.3 %).　No release was detected from 3 suprofen ointments.

Conclusion: Differences in the additives may have been a cause of the observed differences in release over 0-4 h.　This study may serve as a useful index for pharmacists to propose and select appropriate drugs.