MUCOADHESIVE, THERMORESPONSIVE, PROLONGED-RELEASE VAGINAL GEL FOR MICROBICIDE

  A novel mucoadhesive, thermoresponsive vaginal gel for microbicide was developed with gelation temperature 24-35 °C. Poloxamer 407 (P407) or: and poloxamer 188 (P188) were used to confer the temperature-sensitive gelation property. The mixtures of P407 (15%) and P188 (15–20%) existed as a liquid at room temperature, but gelled at 30–36°C. To modulate the gel strength and the bioadhesive force of Ciclopirox olamine gel, mucoadhesive polymer such as polyox WSR N-60K was used. Among bioadhesive polymers, polyox polymer enhanced gel strength most efficiently. These polymers reinforced the bioadhesive forces 4-7 fold compared to P407/P188 (15:15) alone and 3-6 fold compared to P407/P188 (15:20) alone. Differential scanning calorimetry (DSC) was employed to investigate the effect of poloxamer gel on the conformational changes of rat vaginal membrane. The in-situ gelling liquid with polyox polymer inserted into the vagina of women without difficulty and leakage and retained in the vagina at least 6-8 h. These results suggest that in situ-gelling and mucoadhesive vaginal microbicide gel for women can be further developed as a more convenient and effective vaginal dosage form for treating sexually transmitted disease.   Key-words: Mucoadhesion, Vaginal drug delivery, Polyox polymers, Microbicide, Sexually transmitted disease, Conformational change