Mucoadhesive gels loaded with ciclopirox olamine containing SLN for sustained vaginal drug delivery: In vitro and in vivo characterization

In the current study, ciclopirox-olamine loaded solid lipid nanoparticles (SLNs) were prepared and optimized by Box-Behnken design. The logically optimized drug loaded SLNs (F1–F3) were prepared by solvent injection and sonication method and were subjected to evaluation for particle size, PDI, zeta potential, morphology, entrapment efficiency and in vitro permeation study. The in vitro permeation data revealed that SLN (F1) had a comparatively bigger size of 222.42 ± 5.17 nm which showed less permeation through the vaginal mucosa, a pre requisite of local vaginal infection treatment. Amongst the F1-F3 SLNs; F1 formulation exhibited maximum entrapment efficiency of 87.33%. and hence SLN (F1) was selected for incorporation into mucoadhesive gel and submitted for further studies. Various gels comprising of carbopol 934 and 940 were developed and evaluated for pH, spreadability, consistency, homogeneity, and content. The gel SLN-G1 was optimized in terms of consistency, adhesiveness, and syringibility and compared with marketed formulation. The percentage of drug permeation were found 18.14, 17.24, and 55.28% for SLN-G1, F1, and marketed formulation, respectively, after 24 h. In vitro histopathological and toxicity studies showed that SLN-G1 exhibited no epithelial loss of the tissues. In vivo bioadhesion study revealed prolonged retention of the bioadhesive gel after administration into rat vaginal cavity.