Rectal gel (Ritschel WA, Ritschel GB, et al. (1988) and suppositories has shown accurate results.But due to absence of absorption enhancers, bioavailability of therapeutic peptides and proteins through rectal administration is less than achieved by intramuscular, intravenous or subcutaneous route of administration so absorption enhancers are used and it was found that sodium salicylate and 5methoxysalicylate is proved successful in enhancing the rectal absorption of insulin.(Yun M, Choi H, Jung J, Kim C. (1999).