Rectal drug delivery: A promising route for enhancing drug absorption

Rectal drug delivery is an efficient alternate to oral and parenteral route of administration in partial avoidance of first pass metabolism and protein peptide drug delivery. This route allows both local and systemic therapy of drugs. Controlled absorption enhancement of drugs can be achieved by the rectal route because of the constant conditions in the rectal environment. In the present review various absorption enhancers with their mechanism of action in improving drug absorption through rectal epithelium and the potential of rectal route in delivering protein and peptides, analgesics and antiepileptics are discussed. This review also presents affects of various absorption promoting adjuvant on the rectal absorption of drugs.