Objective: Mefenamic acid (MFA) is an NSAID that exhibits anti-inflammatory analgesic and antipyretic activity. Peak plasma levels are attained in 2-4 h and the elimination half-life approximates 2 h, repetitive administration of tablets for 3-5 times a day is desired. It is supplied only in the form of tablets for oral administration. In acute conditions drug administered parenterally could give rapid relief from severe symptoms like pain. Thus, formulation of injectable formulation of MFA could be better alternative compared to conventional tablet dosage form. The low aqueous solubility of MFA precludes its use in parenteral formulation development.
Methods: In this work attempt were made to enhance the aqueous solubility of mefenamic acid using mixed solvency technique. For that different hydrotropic agents such as Urea, Sodium acetate, sodium benzoate, sodium citrate and their blends were evaluated. Optimal concentration of hydrotropic agent in blend was determined using D-optimal mixture experimental design. The optimized bled was used to develop the aqueous injection of mefenamic acid. The developed injection was subjected for various quality control tests and stability of developed formulation was also evaluated.
Results: The aqueous solubility in optimized blend of hydrotropic agent batches (U: SA: SB: SC, 4:4:23:9 %w/v) showed 835.71-fold compared to MFA solubility in distilled water. The quality control tests for parenteral formulation and accelerated stability study were found to be within prescribed limits and stable.
Conclusion: The inadequate solubility of MFA was overcome, and aqueous injection was successfully developed which can be serve as cost effective treatment in various indications
