Development of Misoprostol Suppositories for Postpartum Hemorrhage

Misoprostol is a prostaglandin E1 analogue used to prevent and treat gastric ulcers. It has been commonly used in gynecology and obstetrics, especially for the management of postpartum hemorrhage (PPH). For this purpose, 1000 μg intrarectal (insertion of five 200 μg tablets) has been recommended as the third line after injectable oxytocin and methylergometrine. We proposed to manufacture a 1000 μg misoprostol suppository by determining formulation, release and stability. The administration facility was also evaluated. Several formulations of misoprostol suppositories were set up and evaluated. Misoprostol tablets and lipophilic bases (Hard fat—Adeps solidus Ph. Eur., Witepsol? H15 and Suppocire? AM and AS2X) were used to obtain suppositories. Surfactants were also tested (polysorbates Tween? 20, Tween? 80 and sodium lauryl sulfate (SLS)). The formula was monitored by the misoprostol release curve with an in vitro test and dosed by a HPLC method. Stability was determined by evaluating the percentage of misoprostol content remaining over the time in suppositories stored at 4℃ and 25℃. Facility of use versus tablets was evaluated by obstetricians of a Swiss regional hospital using a questionnaire. Misoprostol release was facilitated by adding surfactant to the lipophilic base. After 30 minutes, 59% ± 1.4% and 57% ± 8.2% of misoprostol was released with Adeps solidus + 1% SLS and Adeps solidus + 5% Tween 20 respectively. SLS was discarded to the final formula because of its irritating effect. After 7 months, suppositories still contained 94% ± 3.7% misoprostol with storage at 4℃. The administration was considered easier and faster compared with intra rectal use of tablets. The formula, consisting of 5 crushed misoprostol tablets dispersed in a suppository base made of Adeps solidus + 5% Tween? 20, is stable for at least 7 months at 4?C and facilitates the rectal administration of misoprostol in the treatment of PPH.