The aim of the present work is fabrication of dual cross linked sodium alginate (SA)/montmorillonite (MMT) microbeads as a potential drug vehicle for extended release of curcumin (CUR). The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. The developed beads were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD) and scanning electron microscopy (SEM). The effect of MMT on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into Korsmeyer-Peppas equation.

Hydrogels were prepared from 2-hydroxy ethyl methacrylate and acrylamidoglycolic acid using N,N’-methylene bis acrylamide as a crosslinking agent in presence of potassium persulfate initiator. The average molecular mass between crosslinks (M _c) and polymer-solvent interaction parameter of hydrogels were determined from equilibrium swelling values. Fourier transform infrared spectroscopy of hydrogels shows the confirmation of the formation of co-polymeric hydrogels. Scanning electron microscopy of hydrogels shows the porous network structure. Differential scanning calorimetry and X-ray diffraction were performed to understand the crystalline nature of hydrogel and drug after encapsulation in to hydrogels. In vitro release studies indicated the release of 5-Fluorouracil for more than 12 h.

Chitosan-Poly (vinyl pyrrolidone), designated as CS-PVP, blend microspheres loaded with an anti-diabetic drug metformin hydrochloride (MH) were prepared using water-in-oil (W/O) emulsion method and used for controlled drug release studies. Microspheres were characterized by Fourier transform infrared spectroscopy (FTIR) to confirm the crosslinking reaction. Scanning electron microscopy (SEM) was also used to assess the surface morphology of particles prepared. The quantities of release of MH-loaded formulations were studied in terms of variation of blend composition and amount of crosslinking agent. DSC and XRD techniques indicated a uniform distribution of MH drug particles in microspheres, whereas SEM suggested the spherical structure of the microspheres with slight rough surface. The in vitro drug release indicated that the particle size and release kinetics depend upon blend composition, amount of cross-linking agent used, and amount of MH present in the microspheres. The prepared microspheres showed 50–82% encapsulation efficiency, which suggested that these IPN microspheres are suitable for controlled release of drugs up to 8 h.