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Effect of eluant properties on drug release from cellulose acetate butyrate-coated drug resin complexes

1988; Elsevier BV; Volume: 48; Issue: 1-3 Linguagem: Inglês

10.1016/0378-5173(88)90266-9

1873-3476

Omar Sprockel, W Prapaitrakul,

Analytical Chemistry and Chromatography

Phenylpropanolamine adsorbed onto sulfonic acid cation-exchange resin particles was coated with cellulose acetate butyrate using an emulsion-solvent evaporation technique. Release of drug from such microcapsules required counter-ions in the eluting media, which permeated the coating and displaced the drug from its binding sites. The type of counter-ion had a significant influence on the rate of drug release; in the presence of hydrogen ions release was rapid, but if the eluant contained calcium ions release was slow. Eluants with low pH values caused a more rapid release of drug from the coated drug-resin complexes when compared to eluants of higher pH values, even though the ionic strenght was maintained constant. An increase in ionic strenght at selected pH values resulted in an enhancement of the drug release rate, with the increase being more noticeable at lower pH values.