title: Optimization of an aqueous tablet-coating process containing carboxymethylated Cassia fistula gum.
abstract: The present investigation was aimed at developing and optimizing a simple aqueous tablet-coating formulation and its process. 5-Fluorouracil (5-FU) was used to ascertain the relative lipophilic/hydrophilic behavior of the coating system. Optimization was performed by evaluating the adhesive force strength and cohesive force strength of the tablet coat using a texture analyzer. The in vitro release of 5-FU was found to decrease with an increase in (tablet surface-coat) adhesive force strength. The (tablet-tablet) cohesive force strength was reduced by the addition of magnesium silicate to the coating solution. The addition of magnesium silicate (0.2% w/v) to the carboxymethyl Cassia fistula gum-chitosan (CCG-CH) coating surface significantly inhibited the release of 5-FU possibly due to an increase in the hydrophobic character of the coated tablet surface. This was possible by coating cohesive force strength reduction coating compositions (CCG-CH (70:30) and 0.3% magnesium silicate). Further, the FTIR-ATR and DSC analyses suggested the pivotal role of magnesium silicate in modifying the release of 5-FU from CCG-CH-coated tablets due to hydrogen bonding of its Si-O-Si or Mg-O groups with -OH moieties of CCG-CH.
authors.affiliation: Pharmaceutics Division, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India.
authors.forename: Parshu Ram
authors.initials: PR
authors.lastname: Rai
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Tiwary
authors.forename: Vikas
authors.initials: V
authors.lastname: Rana
mesh_terms: D000268:Adhesiveness; D000964:Antimetabolites, Antineoplastic / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002366:Cassia / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D005472:Fluorouracil / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D017633:Magnesium Silicates / Q000737:chemistry; D053149:Plant Gums / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013608:Tablets, Enteric-Coated; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000964:Antimetabolites, Antineoplastic; D017633:Magnesium Silicates; D053149:Plant Gums; D013608:Tablets, Enteric-Coated; C005013:Florisil; D048271:Chitosan; D005472:Fluorouracil