Continuous in situ monitoring of the dissolution rate of solid pharmaceutical preparations using a multiple channel fiber-optic chemical sensor

Aim To study the dissolution rate of solid pharmaceutical preparation on-line, a multiple channel fiber-optic chemical sensor based on fluorescence multiple quenching (FOCSMQ) without filtering and sampling was made. Methods Using the multiple channel FOCSMQ linked with computer, the dissolution rates of ofloxacin tablets, metronidazole tablets and nitrofurantoin tablets were monitored continuously on-line. The instrument can give the sample data, display the real time curve and calculate the T_{1/2and Td automatically. A computer was used to select the best function from five common fitting models to fit the dissolution curve. Results The average recoveries of the FOCSMQ method were 97.4%-104.4%, 97.4%-103.8% and 96.6%-102.1%. The RSDs (N=6) of within-day and between-day were less than 5%. The parameters of the dissolution and all results of measurement using the instrument have no significant difference compared with the Chinese Pharmacopoeia (ChP) (2000) method and the United States Pharmacopoeia (USP) (23) method (P>0.05). It does not need sampling and dilution, and never contaminate sample. It can shorten time of the experiment. Conclusion The method is simple, rapid and reliable.}