title: Application and functional characterization of POVACOAT, a hydrophilic co-polymer poly(vinyl alcohol/acrylic acid/methyl methacrylate) as a hot-melt extrusion carrier.
abstract: OBJECTIVE
  The aim of this study was to evaluate the applicability of POVACOAT™, a hydrophilic PVA copolymer, as a solid dispersion (SD) carrier for hot-melt extrusion (HME).
  
  
  METHODS
  Bifendate (DDB), a water-insoluble drug, was chosen as the model drug. DDB was hot-melt extruded by a co-rotating twin screw extruder with POVACOAT™. The SD formability of POVACOAT™ was investigated by varying the composition ratios. Solid state characterization was evaluated by differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy and Fourier transformation infrared spectroscopy. In order to have a better knowledge of the mechanism of dissolution enhancement, dissolution study, phase solubility study and crystallization study of DDB from supersaturated solutions were performed. In addition, the storage stability of the extrudate containing 10% DDB was investigated.
  
  
  RESULTS
  Physical characterizations showed that DDB was amorphous up to 15% drug loading. The phase solubility study revealed an AL-type curve. Moreover, POVACOAT™ was found to have an inhibitory effect on crystallization from supersaturated solutions. Compared with the pure DDB and physical mixture, the dissolution rate and solubility of extrudates were significantly enhanced and the drug loading markedly affected the dissolution of SDs. Furthermore, the stability test indicated that 10% DDB-SD was stable during storage (40 °C/75% RH).
  
  
  CONCLUSIONS
  The results of this study demonstrate that POVACOAT™ is a valuable excipient for the formulation of solid dispersions prepared by HME to improve dissolution of poorly water-soluble drugs.
authors: Department of Pharmaceutics, Shenyang Pharmaceutical University , Shenyang , China.
authors: Ming
authors: M
authors: Xu
authors: Chungang
authors: C
authors: Zhang
authors: Yanfei
authors: Y
authors: Luo
authors: Lishuang
authors: L
authors: Xu
authors: Xiaoguang
authors: X
authors: Tao
authors: Yanjiao
authors: Y
authors: Wang
authors: Haibing
authors: H
authors: He
authors: Xing
authors: X
authors: Tang
mesh_terms: D000179:Acrylates / Q000737:chemistry; D001713:Biphenyl Compounds / Q000008:administration & dosage* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003460:Crystallization; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D004356:Drug Storage; D057927:Hydrophobic and Hydrophilic Interactions; D020366:Methylmethacrylate / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D012995:Solubility
chemical_list: D000179:Acrylates; D001713:Biphenyl Compounds; D004337:Drug Carriers; D011108:Polymers; C465548:bifendate; D020366:Methylmethacrylate; D011142:Polyvinyl Alcohol; C036658:acrylic acid