1994 Volume 17 Issue 3 Pages 427-431
Coated fine granules with water-insoluble film composed primarily of ethylcellulose, containing 20% of sparfloxacin (SPFX) and various amounts of low-substituted hydroxypropylcellulose (L-HPC) (0-52%) in the cores and which masked the bitter taste of SPFX, were orally administered to fasting rats to determine the effect of L-HPC on bioavailability. The release of SPFX in water from four kinds of these coated fine granules containing 0, 25, 40 and 52% of L-HPC showed the pseudo first order kinetics, followed by the second phase, with refractive points between 0.25 and 0.5 h. The rate constant (K1) up to 0.25 h increased with an increase in of the amount of L-HPC in the core, and the rate constant (K2) in subsequent release (the second phase) was lower than K1 in each fine granule. Areas under plasma concentration-time curves (AUC) of SPFX and the peak plasma SPFX levels (Cmax) after oral administration of coated fine granules lacking L-HPC to fasting rats were suppressed to one-eighth and one-ninth, respectively, of those obtained from the core granules that rapidly released SPFX. However, AUC and Cmax from the coated fine granules increased linearly with an increase in the amount of L-HPC in the cores, and nearly equaled those from the core fine granules when the content of L-HPC was 52%. These results confirmed that the addition of L-HPC to the cores increases not only the dissolution rate but also the bioavailability of SPFX.
