FIELD : medicine.SUBSTANCE : invention relates to medicine and chemical-pharmaceutical industry, namely to a transdermal agent for treating and preventing joint and soft tissue diseases, containing a pharmaceutically required amount of cartilage protector, a non-steroid anti-inflammatory agent, an antioxidant for a cartilage protector, a gelling agent capable of forming gels in an acidic medium, mixtures of non-ionic emulsifiers of genus 1 and 2 and a mixture of solvents, where the chondroprotector is glucosamine or a pharmaceutically acceptable salt thereof, the non-steroid anti-inflammatory agent is ketoprofen, characterized in that the mixture of solvents contains N-methylpyrrolidone, polyethylene glycol 400 and water, and the antioxidant for the chondroprotector is sodium metabisulphite, wherein the pH of the medium is in range of 3 to 2.EFFECT : invention provides higher stability of the preparation, which consists in considerable reduction of formation of glucosamine decomposition products and modification of ketoprofen, as well as increase in storage life of at least up to 2 years.6 cl, 7 tbl, 12 dwg