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Xanthan gum(XG) and Poly (vinyl alcohol) (PVA) interpenetrating polymer network(IPN) microspheres were prepared by water in oil emulsion method, loaded with Verapamil Hydrochloride (VMHCl) drug further crosslinked with glutaraldehyde (GA). These microspheres were prepared with various ratios of XG, PVA, drug, cross linker and these were characterized with various techniques. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscopy (SEM).Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. In vitro dissolution experiments were performed in pH 7.4 buffer medium at 37°C. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from all the formulations. Based on the results, this study suggests that VMHCl loaded XG/PVA IPN microspheres were suitable for sustained release application. [ABSTRACT FROM AUTHOR]

This paper reports the fabrication of gelatin/karaya gum microspheres by emulsion crosslinking method for controlled release of distigmine bromide. The microspheres were crosslinked with the help of glutaraldehyde and used for controlled oral delivery of distigmine bromide. The obtained microspheres were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Drug release kinetics of the microspheres is investigated in simulated intestinal fluid pH 7.4 at 37oC. Results illustrated that microspheres was influenced by the pH of test mediums, which might be suitable for intestinal drug delivery. The drug release kinetics was analyzed by evaluating the release data using different kinetic models. [ABSTRACT FROM AUTHOR]

Sodium alginate (NaAlg)/poly (vinyl alcohol) (PVA) blend microspheres (MS) were prepared by water-in-oil (w/o) emulsion method. These polymer microspheres were crosslinked with glutaraldehyde and loaded with metformin hydrochloride (MHC). The microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis to confirm the molecular dispersion of the drug, thermal stability, morphological properties, and crystallinity of the polymer matrix before and after blending. SEM of the microspheres suggested the formation of microspheres in spherical structure. Drug release data were analyzed using an empirical equation to understand the nature of drug transport through polymeric matrices. The controlled release (CR) characteristics of the polymer matrices was investigated in pH 7.4 media and from the results it was obtained that the drug was released in controlled manner up to 10 h. The physico-chemical properties of the microspheres were studied by calculating drug entrapment efficiency and drug release kinetics. Percent of encapsulation efficiency (% EE) decreased with increase in crosslinking agent (GA) and PVA content in the microspheres. The optimum % EE (80%) was observed in case of MS containing 40% of PVA with 15% MHC. The release profiles indicate that the release of MHC decreases with increasing the PVA/NaAlg (w/w) and drug/polymer ratio. At the end of 10 h, the highest release of MHC was found to be 96% for MS containing PVA/NaAlg (40 : 60) and 15 wt % drug loaded. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Poly(acrylamide-co-acrylamidoglycolic acid) co-polymeric microspheres cross-linked with N,N-methylene bisacrylamide have been prepared by free radical emulsion polymerization using varying amounts of acrylamide (AAm), acrylamidoglycolic acid (AGA) and N,N-methylene bisacrylamide (NNMBA). Triprolidine hydrochloride (TPH) was loaded into these microspheres during in situ polymerization. The microspheres have been characterized by Fourier Transform Infrared Spectroscopy (FT-IR), to confirm the formation of co-polymer. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were used to understand the drug dispersion in these microspheres. Scanning electron microscopy (SEM) was used to assess the surface morphology of particles prepared. In vitro release of TPH has been studied in terms of composition, amount of cross-linking agent and amount of TPH in the microspheres. The microspheres with different co-polymer compositions have been prepared in yields ranging from 75-80%. DSC and XRD indicated a uniform distribution of TPH particles in microspheres, whereas SEM suggested the formation of distinct spherical shape microspheres. The in vitro drug release indicated release kinetics depending upon co-polymer composition, amount of cross-linking agent used and amount of TPH present in the microspheres. Prolonged and controlled release of TPH was achieved when drug was loaded in the co-polymer and the drug was released in a controlled manner for up to 12 h. [ABSTRACT FROM AUTHOR]

Cellulose acetate butyrate-poly(vinyl pyrrolidone) (CAB-PVP) blend microspheres were prepared using the solvent evaporation technique using poly(vinyl alcohol) as an emulsifying agent. Atenolol (ATNL), an antihypertensive drug, was successfully loaded into these microspheres. Effect of experimental variables such as CAB/PVP ratio on ATNL encapsulation efficiency, release rate, size and morphology of the microspheres has been investigated. ATNL-loaded microspheres were analyzed using differential scanning calorimetry to investigate the crystalline nature of ATNL after encapsulation. DSC results indicated a non-uniform dispersion of ATNL in CAB-PVP blend matrix. Scanning electron micrographs indicated the formation of spherical microspheres. Mean particle size of the microspheres, as measured by the laser light scattering technique, ranged between 100 and 120 μm. An encapsulation of about 80% of ATNL was achieved. In vitro dissolution experiments performed in pH 7.4 buffer medium indicated the controlled release of atenolol from the blend microspheres up to 10 h. [ABSTRACT FROM AUTHOR]

Blend microspheres of chitosan (CS) and guar gum (GG) have been prepared using the water-in-oil (w/o) emulsion method. Cefadroxil was loaded into the microspheres and cross-linked with glutaraldehyde, leading to the formation of a semi-interpenetrating polymer network (IPN) structure. The microspheres have been characterized by scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. Scanning electron micrographs showed the formation of non-uniform microspheres with the rough surface. X-ray diffraction and differential scanning calorimetry studies of the plain and the drug-loaded microspheres indicated that drug is dispersed at the molecular level in the semi-IPN matrix. In vitro dissolution experiments performed in pH 7.4 buffer medium indicated a sustained and controlled release of cefadroxil from semi-IPN microspheres up to 10 h. The amount of drug loaded into microspheres, CS-GG composition of the blend and the amount of cross-linking agent used have shown dependencies on the release of cefadroxil from the semi-IPN microspheres. [ABSTRACT FROM AUTHOR]