Development and evaluation of a mucoadhesive drug delivery system for dual-controlled delivery of nonoxynol-9

A mucoadhesive drug-delivery system (AmDDS) was developed using carbopol 934P to achieve dual-controlled delivery of N-9 and EDTA for enhanced fertility control. The effects of mucoadhesive polymers and calcium-related interaction on the residence characteristics of AmDDS within the vagina and the release kinetic profile of N-9 from AmDDS were investigated. Maximum adhesion force and work of adhesion shear derived from mucin-polymer interaction between AmDDS and lamb vaginal mucosa increased with increasing the carbopol 934P loading in AmDDS. The maximum adhesion force of AmDDS to lamb vaginal mucosa decreased with increasing pH of buffer in which polymer was dispersed. The mucoadhesive strength of AmDDS to lamb vaginal mucosa increased with EDTA, but decreased with calcium, indicating that divalent cations play an important role in mucus-carbopol adhesion. The amounts of N-9 released from AmDDS followed a profile, which was similar to a Q vs. t(1/2) pattern. The optimal loading dose of N-9 in AmDDS to achieve appropriate release of N-9 was of the order of 1.0%. The release flux was not affected by EDTA, but was reduced in the presence of calcium chloride. These results indicate that AmDDS seems suitable to achieve controlled release of N-9 for prolonged spermicidal action and enhanced fertility control.