Dissolution rate studies I. Continuous recording technique for following rapid reactions in solution

An automatic recording apparatus was developed to follow the process of dissolution. Results were obtained as a recording of per cent transmittance vs. time. The recorder was equipped with various speed chart drive motors that permitted readings to be taken from the graph at intervals down to 0.375 sec. Several experiments were performed to demonstrate the applicability of this apparatus to the determination of dissolution rates, and constants obtained agreed well with those obtained by the usual method of removing samples with a pipet.