[Therapy of rheumatic disease with a hydroxyethylsalicylate gel. Results of 2 clinical studies of effectiveness and bioavailability].

Two clinical studies were carried out to investigate the efficacy and safety as well as the local and systemic availability of a hydroxyethylsalicyclate gel. A double blind, multicenter trial, involving 113 patients with nonarticular rheumatic back pain, revealed statistically significant relief of pain as compared with placebo. Local and systemic tolerance was excellent. An open study of bioavailability after local application in 16 patients showed a mean salicylate concentration of 0.93 +/- 0.5 microgram/ml in the synovial fluid and 0.40 +/- 0.23 microgram/ml in the synovial membrane, compared with 0.14 +/- 0.04 microgram/ml in the serum. Genetisinic acid was not detected, while OH-hippuric acid was detected only in the serum and synovial fluid.