Determination of required hydrophilic-lipophilic balance of Amesiodendron chinense (Merr.) Hu oil and development of stable cream formulation

Amesiodendron chinense (Merr.) Hu oil is reported to use for the treatment of skin disease by Thai folk medicine. Its hydrophilic-lipophilic balance (HLB) value is very important for developing a stable cream formulation. This study aimed to determine the required hydrophilic-lipophilic balance (rHLB) value of Amesiodendron chinense (Merr.) Hu oil and to develop a stable cream formulation. Herbal cream containing Amesiodendron chinense (Merr.) Hu oil was prepared by phase inversion temperature technique using water, Tween80, and Span60. The first series of 11 emulsions with HLB values ranging from 5.0 to 15.0 and the second series of eight emulsions with a smaller interval in HLB values from 5.0 to 7.8 were prepared. rHLB of coconut oil was also determined for validation of methodology. Creaming index is the established parameter to determine rHLB and to develop stable emulsion. Emulsions with optimum emulsifier concentration resulted in less percentage-creaming index. Utilizing determined rHLB, Amesiodendron chinense (Merr.) Hu cream was formulated and evaluated for different physical parameters including viscosity, color, odor, texture, and pH. Finally, the results showed the rHLB value of coconut oil and Amesiodendron chinense (Merr.) Hu oil was 5.4 and 6.2, respectively. The stable creams were developed with a 3% emulsifier. Physical parameters were found to be consistent over 6 cycles of accelerated stability test under 4 and 45○C. Physical properties of cream evaluation ensure the stability of the developed cream. rHLB value of Amesiodendron chinense (Merr.) Hu oil was exhibited, and the stable creams were successfully formulated by utilizing determined rHLB.