<![CDATA[Cutibacterium acnes (C. acnes) is a bacterium that causes acne. To address acne caused by C. acnes, Cinchonine (CN) has been explored as a potential anti-acne agent. The research began by determining the optimal concentration of CN in ointment, cream, gel, and emulgel formulations. Evaluation of the quality of the dosage form includes homogeneity, spreadability, stickiness, viscosity, pH, stability of the preparation, irritation test, and activity test. The optimum concentration of CN was found to be 1.5%; the characterization of the ointment dosage form revealed good homogeneity, with spreadability of 5.03±0.15cm, stickiness measured at 6.96±0.54 seconds, viscosity of 27,100.0±180.28cPs, and pH of 5.19±0.18; the cream exhibited good homogeneity, with a spreadability of 6.10±0.20cm, stickiness of 3.41±0.52seconds, viscosity of 2,850.0±264.58cPs, and pH of 6.38±0.05; the gel showed good homogeneity, with a spreadability of 5.27±0.15cm, stickiness of 12.01±0.43seconds, viscosity of 3,730.0±40.00cPs, and pH of 6.03±0.06; and the emulgel demonstrated homogeneity good, with a spreadability of 6.23±0.15cm, stickiness of 8.81±0.57seconds, viscosity of 6,538.3±524.39cPs, and pH of 5.78±0.03. Antibacterial activity, measured by the zone of inhibition at 18 hours and 24 hours, is as follows: ointment (9.29±0.62 mm and 6.01±0.71 mm), cream (7.17±0.42 mm and 5.96±0.46 mm), gel (8.75±0.22 mm and 5.93±0.38 mm), and emulgel (10.42±0.62 mm and 7.39±0.50 mm). All dosage forms are non-irritant (primary irritation index of 0.00), and emulgel shows better dosage stability. The optimal CN concentration for Cutibacterium acnes as an antibacterial is 1.5%. The emulgel dosage form is superior. Emulgel offers high flexibility, effectively accommodating hydrophilic and lipophilic drugs, with optimal ease of use, stability, and superior drug delivery compared to single-dose forms such as ointments, creams, or gels.]]>
