Formulation of Creams Containing Active Fraction of Cassia fistula L. Barks and its Antibacterial Activity against Propionibacterium acnes and Pseudomonas aeruginosa

Background: Cassia fistula L. has been traditionally used to cure skin diseases. That disease can be caused by various bacteria, such as Propionibacterium acnes and Pseudomonas aerugniosa. Objective: the objective of this research was to formulate cream containing active fraction of Cassia fistula bark and to study the antibacterial activity as well as physical stability of the active substance after formulation. Materials and Methods: The cream base were oilin- water (O/W) and water in oil (W/O) type. Antibacterial activity test had been performed by using agar diffusion method. Determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were conducted by microdilution method. The active fraction was formulated into creams with concentration of 4 -6x MIC. Physical evaluation of creams including organoleptic, pH, viscosity, TLC (Thin Layer Chromatography) profiling and antibacterial activity against both tested bacteria were evaluated during 28 days of storage. Results: The results showed that ethyl acetate fraction was the most active, having MIC and MBC values of 175 and 350 ppm respectively against P. acnes, while those against P. aeruginosa were 400 and 800 ppm. Optimation on creams using different type of cream bases showed that either O/W or W/O creams remained stable during 28 days of storage in terms of organoleptic and pH. The viscosity increased in O/W and decreased in W/O type. Qualitative analysis by TLC profiling showed that the ethyl acetate fraction of Cassia fistula as chemical compounds in creams was relatively stable as the profile remained the same after 28th day of storage. Result of antibacterial activity test on cream with O/W base was unchange after 28 day, while that with W/O revealed no activity which may due to poor diffusion within the cream base as media. Conclusion: active fraction of Cassia fistula can be formulated into cream with O/W cream base system.