The objective of this study was to measure
rupture time of
gelatin and
hypromellose (
hydroxypropyl methylcellulose or HPMC) capsules using a novel approach based on real-time dissolution spectroscopy.
Rupture time was measured in standard dissolution apparatus at a constant temperature using a dip-type fiber-optic probe.
Labrasol released from the capsules was treated as the marker of the
rupture process. Light scatter generated by the emulsified
labrasol was detected by an ultrafast monochromator at scan rates approximating 24,000 nm/min. This technique was validated by measuring the dissolution time of
gelatin capsules.
Rupture times of
hypromellose capsules were studied as a function of
capsule size,
capsule grade, and dissolution medium. Statistical correlations were analyzed by ANOVA.
Rupture time of
hypromellose capsules was dependent on both the medium and the grade of the
capsule, and was independent of
capsule size. The composition of the dissolution medium contributes to the
rupture time of the capsules and should be considered when fast release and quick
biological response is desired. Release delay, however, may not manifest itself in vivo and the time to maximum plasma concentration may not be significant.