DICLOFENAC SODIUM-CONTAINING OILY PLASTER PREPARATION FOR EXTERNAL USE

摘要

PROBLEM TO BE SOLVED: To obtain the subject plaster preparation capable of efficiently percutanously absorbing diclofenac sodium and free from problem of irritation to skin by formulating diclofenac sodium with a specific fatty acid. SOLUTION: This oily plaster preparation for external use is obtained by formulating a tacky base for preparation with a 10-18C fatty acid which is liquid at ordinary temperature and isostearic acid. Caprylic acid, oleic acid, linoleic acid or linolenic acid is preferable as the fatty acid. A composition comprising 30-50 wt.% styrene-isoprene-styrene block polymer, 25-50 wt.% tackiness-providing resin and 0.1-2 wt.% antioxidant is preferable as the tacky base. The formulation ratio of diclofenac sodium is preferably 0.5-6 wt.% and formulation ratio of a mixture of isostearic acid with the fatty acid is preferably 2-15 wt.% and mix ratio of isostearic acid to the fatty acid is preferably (8:2) to (4:6).