Sodium lauryl sulfate impedes drug release from zinc-crosslinked alginate beads: switching from enteric coating release into biphasic profiles

Int J Pharm. 2008 Feb 28;350(1-2):291-300. doi: 10.1016/j.ijpharm.2007.09.010. Epub 2007 Sep 14.

Abstract

The aim of this research is to investigate the effects of sodium lauryl sulfate (SLS) on ionotropically cross-linked alginate beads. Different levels of SLS were mixed with sodium alginate and chlorpheniramine maleate (as loaded model drug). The resulting viscous solutions were dropped onto aqueous solutions of zinc or calcium ions for ionotropic curing. The generated beads were assessed by their drug releasing profiles, infrared and differential scanning colorimetery (DSC) traits. SLS was found to exert profound concentration-dependent impacts on the characteristics of zinc-crosslinked alginate beads such that moderate modifications in the levels of SLS switched drug release from enteric coating-like behavior to a biphasic release modifiable to sustained-release by the addition of minute amounts of xanthan gum. Calcium cross-linking failed to reproduce the same behavior, probably due to the mainly ionic nature of calcium-carboxylate bonds compared to the coordinate character of their zinc-carboxylate counterparts. Apparently, moderate levels of SLS repel water penetration into the beads, and therefore minimize chlorpheniramine release. However, higher SLS levels seem to discourage polymeric cross-linking and therefore allow biphasic drug release.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / administration & dosage
  • Alginates / chemistry*
  • Calorimetry, Differential Scanning
  • Chemistry, Pharmaceutical
  • Chlorpheniramine / administration & dosage
  • Chlorpheniramine / chemistry
  • Glucuronic Acid / administration & dosage
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / administration & dosage
  • Hexuronic Acids / chemistry
  • Sodium Dodecyl Sulfate / chemistry*
  • Solubility
  • Spectrophotometry, Infrared
  • Tablets, Enteric-Coated
  • Zinc / chemistry*

Substances

  • Alginates
  • Hexuronic Acids
  • Tablets, Enteric-Coated
  • Sodium Dodecyl Sulfate
  • Chlorpheniramine
  • Glucuronic Acid
  • Zinc