Résumé
OBJECTIVE: To determine the optimum amount of humectant (glycerin) in eczema cream to solve the water loss and cracking problem during storage. METHODS: Eight eczema cream samples with different dosages of glycerol were prepared. The percentage of water loss was determined, and the dynamic equations at different temperatures for different times were established. The constant of water loss rate was calculated, the speed of water loss was compared for the eight samples with the method of test for grade consistency, and the optimal amount of humectant (glycerin) was determined. RESULTS: The mathematical expressions for the samples at different temperatures all complied to power function model, and the constant of water loss rate was the slope of the equation. The rating tended to be consistent, which indicated that there were significant differences in the water loss rate constants of the samples at different temperatures (P < 0.05). The grade summation of Ri and moisturizing effect tended to top when the dosage of moisturizer (glycerin) was 13.6% in eczema cream. CONCLUSION: The optimal amount of glycerol in eczema cream is 13.6% with the lowest water loss in the temparature range of 25-65℃.