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Deaggregation behavior of a relatively insoluble substituted benzoic acid and its sodium salt

1967; Elsevier BV; Volume: 56; Issue: 10 Linguagem: Inglês

10.1002/jps.2600561006

1520-6017

Armando J. Aguiar, Joyce E. Zelmer, Arlyn W. Kinkel,

Environmental Chemistry and Analysis

The deaggregation rates of a relatively insoluble benzoic acid derivative and its soluble sodium salt were studied. Based on the postulate that the deaggregation rate follows a first-order process, equations were developed to measure the rates quantitatively. A spectrophotometric procedure, which is simple and convenient for use routinely, is described. The surface area of the aggregates at the final state was estimated from a correlation between the absorbance measurements and the surface area determined with a Coulter counter. It was seen that encapsulating or tableting these compounds decreased the deaggregation rates. The addition of a nonionic polyol surfactant or the sodium salt of polymerized alkyl naphthalene sulfonic acid enhanced the rates. A relationship between the deaggregation rate and rate of solution of the acid in simulated intestinal fluid T.S. (U.S.P. XVI) is demonstrated. The biopharmaceutical significance of the deaggregation rate is discussed.