Adsorption characteristics of norfloxacin to pharmaceutical additives

Abstract

Norfloxacin is a very potent drug, adsorption of even a few milligrams of this drug may account for a significant fraction of total dose, hence, adsorption effect might be of great significance. The results of in vitro adsorption studies of norfloxacin to different pharmaceutical additives are plotted on the basis of Langmuir Equation. The linear nature of the adsorption isotherms shows that the adsorption process is due to monomolecular layer. Adsorption constants were calculated to determine the binding capacity of this drug to various additives. The adsorbents with their decreasing binding capacity are as follows: Activated charcoal (33.0 × 10-3) > Bentonite (17.0 × 10-3) > Kaolin (9.5 × 10-3) > Methyl cellulose (8.6 × 10-3) > Potato starch (7.4 × 10-3) > Talc (6.0 × 10-3) The mechanism of adsorption has been discussed in light of physical characteristics of the adsorbents. © 1988 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.