In-vitro release of diazepam from conventional and double-layer polyethylene glycol suppositories

Abstract

A dissolution cell of simple design has been devised specifically for the assessment of hydrophilic suppositories. The measured total percentage release of three conventional diazepam formulations has been measured and interpreted in terms of appropriate kinetic microconstants. The desirability of assessing such tests in terms of a dissolution half-life is discussed.

A novel hydrophilic double-layer suppository has been formulated and its measured dissolution profile is described both mechanistically and in terms of suitably derived kinetic equations. The initial total percentage release of this formulation was significantly greater than that of the conventional suppositories which were tested. It is suggested that a double-layer suppository of this type could be therapeutically advantageous in the treatment of epilepsy.