Development and Evaluation of Microemulsions for Transdermal Delivery of Insulin

Insulin-loaded microemulsions for transdermal delivery were developed using isopropyl myristate or oleic acid as the oil phase, Tween 80 as the surfactant, and isopropyl alcohol as the cosurfactant. The pseudoternary phase diagrams were constructed to determine the composition of microemulsions. The insulin permeation flux of microemulsions containing oleic acid as oil phase through excised mouse skin and goat skin was comparatively greater than that of microemulsions containing isopropyl myristate as oil phase. The insulin-loaded microemulsion containing 10% oleic acid, 38% aqueous phase, and 50% surfactant phase with 2% dimethyl sulfoxide (DMSO) as permeation enhancer showed maximum permeation flux (4.93 ± 0.12 μg/cm2/hour) through goat skin. The in vitro insulin permeation from these microemulsions was found to follow the Korsmeyer-Peppas model (R2 = 0.923 to 0.973) over a period of 24 hours with non-Fickian, “anomalous” mechanism. Together these preliminary data indicate the promise of microemulsions for transdermal delivery of insulin

Floating bioadhesive matrix tablets of ondansetron HCl: Optimization of hydrophilic polymer-blends

The work investigates the development and optimization of floating bioadhesive matrix tablets of ondansetron HCl for gastroretentive delivery using 2 3 factorial design. The effects of xanthan gum, guar gum, carbopol 934 P as hydrophilic polymer-blends on drug release were analyzed. The optimized tablets were floated well in simulated gastric fluid (SGF) (>8 h) with no lag-time and also showed a good bioadhesion time (5.23 ± 0.25 min) on goat intestinal mucosa in SGF. The in vitro drug release of these tablets showed sustained ondansetron HCl release over 8 h, which correlated well with controlled-release (zero order) pattern with super case-II transport mechanism

Soluble starch-blended Ca2+-Zn2+-alginate composites-based microparticles of aceclofenac: Formulation development and in vitro characterization

The present article describes development of starch-blended Ca2+-Zn2+-alginate microparticles of aceclofenac for attaining gastric protection and controlled release delivery. Different formulations (F1 to F7) of microparticles were prepared by ionotropic gelation method and subjected to characterization studies. In vitro drug release studies were performed in 0.1 N HCl (pH 1.2) for initial 2 h and additional 5 h in phosphate buffer (pH 7.4). These microparticles were characterized by SEM, FTIR spectroscopy and XRD analyses. The formulation F7 (prepared using sodium alginate of 300 mg, soluble starch 250 mg, 5% CaCl2 and 1% ZnSO4) was selected as the optimized formulation, which exhibited entrapment efficiency of 85.73%, particle size of 1610 μm and viscosity of 802.16 cps. In vitro drug release from the formulation F7 revealed maximal 38% drug release within 7 h indicating sustained drug release profile from the prepared formulation. Also, in vitro swelling studies revealed maximal swelling within the period of 2 h at pH 7.4 for all these microparticles. The surface morphology studies performed using SEM showed smooth and spherical nature of the microparticles. Evaluation of drug release kinetic indicated fitting as per Korsmeyer-Peppas model and construed drug release via Fickian diffusion mechanism. Drug-excipient interaction studies using FTIR spectroscopy showed no change in characteristic peaks of the drug, while powder XRD revealed absence of sharp crystalline peaks of the drug. Overall, the present investigation corroborated successful development of microparticles of aceclofenac as an effective and cost-effective approach for oral delivery of aceclofenac. Keywords: Polymer composites, Ionotropic gelation, Microparticles, Drug release, Diffusion, Dissolutio