Drug substance, drug product, and diluent
ICH
The validation test was conducted to prove that the HPLC (high-performance liquid chromatography) method could provide consistent measurement results of LL-37 levels in accordance with the established and well-documented specifications based on AOAC (Association of Official Analytical Chemists) and ICH (International Conference on Harmonization) criteria [The LL-37 cream contained purified LL-37 substance from Isca Biochemicals, Exeter, UK. An LL-37 solution containing 50 mg of LL-37 and 20 g of purified water was added to 100 g of base cream to reach an LL-37 concentration of 0.5 mg/g. The cream formulation consisted of 7 g of stearic acid, 2 g of cetyl alcohol, 0.5 g of TEA (triethanolamine), 20 g of paraffinum liquidum, 10 g of glycerin, purified water (until the formulation reached 100 g), and 5% citric acid to reach a pH of 6.28 in room temperature. The creams were then distributed and packed in 20 jars, so each contained 5 g of LL-37 cream. The placebo cream was exactly 100 g of base cream without the LL-37 solution. It was also distributed and packed in 20 jars. The placebo cream was matched to the LL-37 cream for volume, color, consistency, and smell.