Abstract: The present invention relates to a method of administering a compound of Formula I: wherein R1 is hydrogen or C1-6-alkyl; R2 is C1-6-alkyl or adamantyl; R3 is C1-6-alkyl or hydroxy; or R2 and R3 taken together are —(CR6R7)n—; R4 is C2-8-alkyl, C2-8-alkenyl, C2-8-alkynyl, —OCH2R5 or C2-8-alkanoyl, or hydrogen when R3 is hydroxy; R5 is C1-6-alkyl, C2-6-alkenyl or C2-6-alkynyl; R6 and R7 are hydrogen or C1-6-alkyl; Y is oxygen or sulfur; and n is 3, 4, or 5, or a pharmaceutically acceptable salts of carboxylic acid of formula I, wherein said method comprises the step of admixing said compound in solid form with a topical carrier to form a topical formulation within seven days prior to first topical administration of said compound.