抄録
The dissolution behavior of fifteen commercial extended-release articles was examined by the dissolution test in order to characterize their behavior in vitro. The articles were classified into six groups according to the formation types. The paddle method for six hours was used for tests, and the media were the first solution (pH 1.2) and the second solution (pH 6.8) in JP XI.
Five articles showed different patterns in the above two media, so that their dissolution seemed to depend on pH. A few articles were also effected by pH on the dissolution although they showed time-dependent behavior. The others showed pH-independent (time-dependent) dissolution. The dissolution curves of time-dependent articles approximated to zero-order or firstorder kinetic model. There was, however, no significant relation between the formation type of articles and their dissolution behavior.
In addition, for time-dependent articles, simulation curves of dissolution were calculated by using “Weibull function” with the data obtained from the dissolution test up to six hours. Since most of all curves conformed to the observed curves, the parameters of the simulation curves were re-calculated only with the data up to three hours to obtain the prediction curves. The predicted rate fitted well to the observed rate after six hours in many articles. Therefore the prediction curves could be applicable to shorten time for the dissolution test.
