Plasma levels of sulfinpyrazone and of two of its metabolites after a single dose and during the steady state.

The pharmacokinetics of sulfinpyrazone, and the plasma levels of its sulfide and sulfone metabolites, have been determined after a single oral dose (400 mg) and during steady-state conditions (4 x 200 mg daily for 6 days) in healthy female volunteers. The plasma half-lives of sulfinpyrazone, the sulfone and the sulfide were 3.7, 3.2 and 14.7 h, respectively, during steady-state. After a single dose and during steady state conditions the half-lives of sulfinpyrazone and the sulfone did not differ significantly. The trough plasma levels of the sulfide metabolite exceeded those of the parent compound in four of the six volunteers on the last day of the study. The data suggest that in man the most likely candidate for the prolonged inhibition of platelet aggregation observed after treatment with sulfinpyrazone is its sulfide metabolite, because of its prolonged elimination.

Preparation, characterization, and stability of new prostaglandin E2 gel for local administration.

A new gel delivery system for the local application of prostaglandin E2 consists of drug incorporated in the matrix of a cross-linked starch polymer. The properties of the starch powder provide a stabilizing milieu for the labile prostaglandin E2 and, by addition of saline, a ready-to-use gel for immediate local administration. The gel offers advantages over existing preparations in terms of chemical and microbiological stability, homogeneity, and dosage safety. This report outlines the pharmaceutical aspects involved in the development of the delivery system.

A new gel for intracervical application of prostaglandin E2.

A new gel-formulation for intracervical application of prostaglandin E2 (PGE2) has been prepared. As a vehicle for the gel a cross-link starch polymer is used. PGE2 substance is added to the starch polymer and after homogenization and lyophilization a PGE2 powder is obtained. The powder can be stored at room temperature for more than four months without inactivation of the prostaglandin. Before clinical application a few ml of saline is added to the powder giving, within 30 seconds, an easily-handled ready to use PGE2-gel. Chemical analysis by spectrophotometric technique reveals that the amount of unchanged PGE2 is the same in the new gel-formulation as in a conventional cellulose gel. In a randomized double-blind study the new PGE2-gel was intracervically applied to twenty nulliparae before abortion by dilatation and evacuation (D & E). Ten women were given a gel containing 0.25 mg PGE2 (PGE2-gel) and ten a gel without PGE2 (placebo gel). It was found that the PGE2-gel, in contrast to the placebo gel, produced a rapid ripening of the cervix facilitating the subsequent D & E. No adverse systemic or local reactions were found during or after the treatment.