Use of Benzene-Free Carbomer 980 in the Formulation of Metronidazole Gel 0.75

The U.S. FDA currently recommends avoiding carbomer grades that contain benzene and recommends benzene-free alternatives (USFDA. Guidance for Industry: reformulating drug products that contain carbomers manufactured with benzene. Center for Drug Evaluation and Research (CDER), Pharmaceutical Quality/CMC. Published in December 2023. Available at: https://www.fda.gov/media/175083/download ). This means that if a finished product is authorized with a carbomer grade containing benzene, it needs to be replaced with a non-benzene carbomer grade. Such an update would also require detailed comparative studies—covering structure, performance, stability, and biological equivalence—to confirm consistent product quality and effectiveness. The current study attempted to replace Carbomer 940 (C940) with Carbomer 980 (C980) in 0.75