METHOD FOR ADJUSTING HARDNESS OF STICK-SHAPED SUBSTRATE CONTAINING LIPID-PEPTIDE-TYPE COMPOUND

There is provided a method for adjusting hardness of a stick-shaped base material comprising a lipid peptide compound. A method for adjusting hardness of a gelled solid base material for skin external application including a surfactant, water, and a lipid peptide compound including compounds of formulae (1) or the like, wherein R 1 is a C 9-23 aliphatic group, R 2 is a hydrogen atom or the like, and R 3 is a -(CH 2 )n-X group, n is a number from 1 to 4, and X is amino group, and the method characterized by comprising adding a pH adjuster to a solution in which the solid base material for skin external application is dissolved, or a solution including a surfactant, water, and a lipid peptide compound including at least one of compounds of formulae (1) to (3) or pharmaceutically usable salts of the compounds, to adjust the pH of the solution to a weak acidic to neutral range, and subsequently, causing gelation of the solution to form a solid base material for skin external application.