Usefulness of Propylene Glycol on Suppository Formulation of Bupurenorphine Hydrochloride

Abstract

Buprenorphine hydrochloride (BP) is a semi-synthetic opiate derived from the morphine precursor thebaine which has been used as a replacement therapy for opiate dependence. Conventionally, BP is widely used as a parenteral injection for postoperative pain and cancerous pain. However, the injection is not preferable for the cases of intractable chronic pain such as cancerous pain, because frequent administration is needed, considerable pain accompanies injection, and treatment at home is not possible. On the other hand, when BP is orally administered it is metabolized quickly in the liver, and a satisfactory analgesic effect is not expected in its oral dosage form. With this background, the development of BP suppositories has been keenly desired.

The characteristic of developed BP suppositories is to formulate propylene glycol (PG) as an additive. The present study suggested that PG improved rectal absorption of BP and relieved the irritative effect on rectal membrane of BP suppositories without PG. In addition, it became possible to manufacture excellent BP suppositories uniform in content by dissolving BP in a suppository base.