Optimization of an aqueous tablet-coating process containing carboxymethylated Cassia fistula gum

AAPS PharmSciTech. 2012 Jun;13(2):431-40. doi: 10.1208/s12249-012-9763-x. Epub 2012 Feb 24.

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.

MeSH terms

  • Adhesiveness
  • Antimetabolites, Antineoplastic / chemistry*
  • Calorimetry, Differential Scanning
  • Cassia / chemistry*
  • Chemistry, Pharmaceutical
  • Chitosan / analogs & derivatives*
  • Chitosan / chemistry
  • Chitosan / isolation & purification
  • Fluorouracil / chemistry*
  • Hydrogen Bonding
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions
  • Kinetics
  • Magnesium Silicates / chemistry
  • Plant Gums / chemistry*
  • Plant Gums / isolation & purification
  • Seeds
  • Solubility
  • Spectroscopy, Fourier Transform Infrared
  • Tablets, Enteric-Coated
  • Technology, Pharmaceutical / methods

Substances

  • Antimetabolites, Antineoplastic
  • Magnesium Silicates
  • Plant Gums
  • Tablets, Enteric-Coated
  • Florisil
  • Chitosan
  • Fluorouracil