RESUMO
Objective: To prepare ligustrazine pamoate (Lig-PAM) sustained-release nanosuspension (Lig-PAM-NSps) and determine its in vitro release characteristics. Methods: Lig-PAM was prepared by hydrophobic salt formation method and its physicochemical properties were characterized. Then, Lig-PAM-NSps was prepared by miniaturized medium grinding method. The prescription and preparation process of Lig-PAM-NSps were optimized by the single factor and orthogonal experiment with average particle size, polydispersity index (PDI) and stability coefficient (SI) as indicators. Lig-PAM-NSps was characterized, and its stability and in vitro release was also investigated. Results: The compound ratio of Lig-PAM prepared by Lig and PAM in the amount of 1:1 was (97.48 ± 0.04)%. Compared with Lig, the solubilities of Lig-PAM in water and simulated body fluids were decreased by 95.50% and 77.39%, respectively. Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) showed that the Lig and PAM formed Lig-PAM. The optimum prescription size of Lig-PAM-NSps was (585 ± 5) nm, PDI was (0.328 ± 0.015) and SI was (0.928 ± 0.012). The scanning electron microscopy (SEM) showed that Lig-PAM-NSps was spherical with uniform size distribution, and the particle size was about 600 nm and its physical stability was good within 60 d. The results of in vitro release showed that Lig-PAM-NSps had obvious sustained-release effect compared with Lig solution within 48 h, and showed the first-order release characteristics [ln(1-Q) = 0.153 67 t + 80.458 14, r = 0.998 26]. Conclusion: The preparation progress of Lig-PAM-NSps is stable and can release Lig slowly in vitro.
RESUMO
Objective: To evaluate therelease characteristicsin vitro, pharmacokinetics in rabbits and in vivo-in vitro correlation of tectorigenin floating sustained-release tablets (TFSRT). Methods: The release characteristics of TFSRTin vitro was detected with HPLC in the artificial gastric fluid. Six Japanese Giant Ear Rabbits as self crossover control, which were given TFSRT and suspension liquid (200mg). The concentration of tectorigenin in plasma was determined with HPLC and the data were processed with PKsolver 2.0 software. Results:The cumulative releaserate of TFSRTin vitro was over 70% in 10 h.The pharmacokineticsin rabbits showed that TFSRT and tectorigenin suspension liquid conformed to the single compartment model and the pharmacokinetic parameters were obtained: tmax: (2.809±0.371) and (0.442±0.138)h, Cmax: (6.317±1.337) and (9.662±2.759) μg/mL, AUC0-t: (74.156±10.420) and (57.059±13.309) μg∙h/mL. The relative bioavailability of TFSRT was (134.63±27.94)%, so there was significant difference between them. Conclusion: TFSRT can release slowly, so it increase the relative bioavailability significantly. The correlation between the absorption in vivo and release in vitro is fine (r=0.9879), so the release rate in vitro can control the quality of TFSRT.