A topically applied cream containing glucosamine sulfate along with a number of other ingredients has proven to be effective in pain reduction for osteoarthritis of the knee. Several studies have shown that glucosamine sulfate and chondroitin sulfate administered orally are effective in reducing pain associated with osteoarthritis of the knee. Glucosamine, however, is subject to degradation in the liver and is also taken up by non-joint tissue. The amount actually reaching the affected knee joint is thus only a small percentage of the original oral dose. Chondroitin sulfate is known to be poorly absorbed from the gastrointestinal tract. In order to overcome these problems researchers at Monash University have evaluated a proprietary cream designed to be applied topically directly to the affected area. The cream contains 30 mg/gram of glucosamine sulfate, 50 mg/gram of chondroitin sulfate, 140 mg/gram of shark cartilage (a source of chondroitin sulfate), 32 mg/gram of camphor, and 9 mg/gram of peppermint oil in a water-soluble cream. The randomized, double blind, placebo controlled trial of the cream involved 59 men and women diagnosed with osteoarthritis of the knee. Thirty of the participants were given the proprietary cream to apply to the affected area as needed while the remaining 29 were given a placebo cream. All participants evaluated their pain daily on a visual analog scale running from 0 to 100 mm. Baseline pain score was 62 mm. The pain score began decreasing on day one in the active cream group and after 8 weeks had dropped to 28 mm as compared to 46 mm in the placebo group. The participants applied the cream 2-3 times every day. The researchers estimate that the cream delivered about 60-120 mg of glucosamine sulfate and 156-300 chondroitin sulfate directly to the affected area. They conclude that topical application of the cream is a safe and effective way of treating pain associated with osteoarthritis of the knee.
Cohen, Marc, et al. A randomized, double blind, placebo controlled trial of a topical cream containing glucosamine sulfate, chondroitin sulfate, and camphor for osteoarthritis of the knee. Journal of Rheumatology, Vol. 30, March 2003, pp. 523-28