Atrix Laboratories has developed a topical gel formulation of the antibiotic dapsone, Atrisone™, using the Solvent-Micropartical (SMPTM) delivery technology. It is being developed for the treatment of acne, pruritis associated with burns, and atopic dermatitis.Results from phase I/II trials in patients with moderate to severe acne have been positive, with Atrisone™ reducing inflammatory and non-inflammatory lesions by about one-half over a short time period. A phase III study for this indication was initiated in the US in March 2001 and enrolment was completed in October 2001. Atrix Laboratories is conducting a small proof-of-concept trial of topical dapsone for the treatment of chronic itch (pruritus) associated with healing burn wounds in the USA. Atrix announced in October 2001 that initial results from this study had indicated that the product had significant efficacy. Atrix Laboratories submitted an IND application to the FDA seeking permission to conduct clinical trials in patients with atopic dermatitis in May 2001.An oral formulation of dapsone is already marketed for the treatment of leprosy and dermatitis herpetiformis.Atrix Laboratories licensed exclusive North American marketing and distribution rights for topical dapsone to Fujisawa in October 2001. Under this agreement, Fujisawa will pay up to $US25 million in licensing fees, milestone payments and funding for research and development. Atrix will be responsible for manufacturing of Atrisone™ on behalf of Fujisawa, which will also have rights to develop the product for additional indications.The Solvent-Microparticle (SMPTM) delivery system is a means of delivering water-insoluble drugs to the skin. It is a 2 stage system which combines dissolved drug with a microparticle suspension of the drug in a single formulation. The dissolved drug permeates into the epidermal layer of the skin, and the microparticle drug is maintained at a high level above the outermost layer of the skin for later delivery.