title: Formulation and evaluation of metronidazole acid gel for vaginal contraception.
abstract: In this study, the efficacy of metronidazole as a local spermicidal agent was investigated. The drug was formulated in a concentration of 5% as an acid gel for vaginal application as a local contraception. The minimum spermicidal concentration of metronidazole was evaluated in-vitro and found to be 0.2% w/v. The formulated gel showed instant immobilization and death of all sperm within 30 s. A clinical study was conducted to determine the drug concentrations in vaginal secretions of healthy women and women with symptoms suggesting genital tract infection every 15 min for a 1-h period after application of 1 g of the gel in the vagina. Drug concentrations in the infected group were significantly lower (P < 0.05) than those in the healthy group at all time intervals. The drug concentrations in vaginal secretions after 1 h of vaginal medication remained above the determined minimum spermicidal concentration (0.2%) in the two groups. Measurement of vaginal pH before and after medication revealed a significant drop (P < 0.05) in pH to its normal value in both healthy and infected groups as a result of gel application. In conclusion, the designed gel has potential advantages of achieving a long retention time and effective drug concentrations in the vagina for at least 1 h after application, and of maintaining vaginal pH within its normal range.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Tanta, Tanta, Egypt. selgizawy@hotmail.com
authors.forename: Sanaa A
authors.initials: SA
authors.lastname: El-Gizawy
authors.forename: Nagwa I
authors.initials: NI
authors.lastname: Aglan
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D000282:Administration, Intravaginal; D000328:Adult; D001424:Bacterial Infections / Q000378:metabolism; D001826:Body Fluids / Q000737:chemistry; D003267:Contraception; D004338:Drug Combinations; D005260:Female; D005782:Gels; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008747:Methylcellulose / Q000737:chemistry; D008795:Metronidazole / Q000008:administration & dosage* / Q000737:chemistry* / Q000494:pharmacology; D008875:Middle Aged; D012212:Rheology; D012995:Solubility; D013089:Spermatocidal Agents / Q000008:administration & dosage* / Q000737:chemistry* / Q000494:pharmacology; D014621:Vagina / Q000378:metabolism; D014623:Vaginal Diseases / Q000378:metabolism
chemical_list: D004338:Drug Combinations; D005782:Gels; D013089:Spermatocidal Agents; D008795:Metronidazole; D008747:Methylcellulose; D019342:Acetic Acid