EXISTING ONCE-A-MONTH COMBINED INJECTABLE CONTRACEPTIVES

Long-acting contraception by monthly intramuscular injection is an att ractive method for family planning which fills a gap in birth control technology. The main advantage of this approach over long-acting (2-6 months) progestin injectables is much better cycle control. To achieve this goal, an estrogen had to be included in the formulation with sig nificant reduction in the progestin dose. Until 1976, there were only three monthly injectables available (Injectable No. 1, Cycloprovera an d Deladroxate), but they were faced with logistic, toxicological or cl inical problems. It took over 15 years to resolve many of these proble ms and add a new product (Mesigyna = 50 mg norethisterone enantate plu s 5 mg estradiol valerate in an oily solution). Cycloprovera, at a low er dose, received the new name of cyclofem and Deladroxate was manufac tured under the trade names of Perlutal or Topasel. The latter require s in-depth re-evaluation of its toxicological hazards. There are many other formulations currently being developed with incomplete data so f ar on safety and efficacy.