Comparative efficacy of intravaginal prostaglandin E2 in the gel and suppository forms for cervical ripening

Thirty-seven patients admitted for labor induction and presenting with unfavorable cervical features were randomized in a single-blind fashion to receive either 3 mg of prostaglandin E2 in an intravaginal gel or a 2-mg dose in a vaginal suppository. With the aid of previously reported placebo data, the intent was to compare the two dosage forms in terms of their ability to promote cervical ripening, and to see which dosage form was more effective in terms of influencing the overall incidence of cesarean section. The two groups showed a comparable improvement (alpha = 0.05) in cervical condition over that of the placebo group, with the mean Bishop score increasing by 2.0 points in the gel group, 2.5 points in the suppository group, and 0.7 points in the placebo group. As the suppository contained a lower dose of drug than the gel, the data support the concept that the type of drug vehicle and dosage form are important variables affecting product performance. No statistically significant difference in the incidence of cesarean section was noted between the two groups or between either group and placebo. This may be attributable to the small sample size and the relatively high proportion of women diagnosed as having cephalopelvic disproportion/failure to progress. Additional studies are warranted.