Mucoadhesive sustained-release tablets for vaginal delivery of Curcuma comosa extracts: Preparation and characterization

Abstract

The objectives of this study were to prepare and characterize the mucoadhesive vaginal tablets of Curcuma comosa (C. comosa) extract for local delivery of the active phytoestrogens in a sustained release manner. The oleoresin-like C. comosa extract was converted into apparently dry powder by adding it into the mixture of polymer, namely polycarbophil (PCP), hydroxypropylmethylcellulose (HPMC) or the blends of PCP:HPMC, and silica. The absence of interaction between C. comosa extract and excipients was confirmed using FTIR. C. comosa mucoadhesive powder was directly compressed into 24-mm capsule shape tablets. All prepared tablets had acceptable physical properties and uniformity of diarylheptanoids (DAs), namely (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (DA1) and (3S)-1,7-diphenyl-(6E)-4,6-hepten-3-ol (DA2). Blending PCP with HPMC could improve swelling and mucoadhesive properties of the tablets (p < 0.05). In vitro release showed that DAs were released over a period of 72 h in a sustained manner. The almost complete DA release was found in the formulation prepared with HPMC, of which the mean dissolution time of DA1 and DA2 stood at 34.7 ± 4.1 and 32.1 ± 3.7 h, respectively. Stability study reveals that C. comosa tablets were stable in terms of tablet properties, DA content and release characteristics when stored in a refrigerator.