Prediction of the bioequivalence of different crystal forms of rifampicin based on physiologically based pharmacokinetic model / 中国药科大学学报

@#The physiologically based pharmacokinetic (PBPK) modeling strategy was adopted to predict the pharmacokinetic behavior of crystal forms I and II of rifampicin in humans, which was used to determine whether the two were bioequivalent.After conducting studies in vitro of the two crystal forms, a rat PBPK model was established based on the pharmacokinetic data of intravenous administration in rats.The model was optimized by the pharmacokinetic data of oral administration in rats.Species were extrapolated to healthy humans, and the extrapolation model was used to predict such pharmacokinetic behaviors as the drug-time curve, absorption site, and absorption amount of the two crystal forms of rifampicin in healthy humans.The prediction results of the healthy human model showed that the cmax of form I and form II rifampicin were 8.42 and 10.35 μg/mL, tmax were 0.40 and 0.32 h,and AUC0-t were both 62.90 μg·h/mL.According to the prediction results of absorption, neither crystal form I nor crystal form II rifampicin was absorbed in the stomach, yet both were completely absorbed in the intestinal tract, with both the absorption site and the absorption amount were basically the same.The pharmacokinetic parameters of both crystal forms I and II of rifampicin were very close, which could indicate bioequivalence.

Thoracolumbar spinal reconstruction with titanium mesh implantation combined with internal fixation after tumor resection: stability and biocompatibility / 中国组织工程研究

BACKGROUND:Clinical resection of thoracolumbar spinal tumor has a great impact on the spinal stability. Positive internal fixation is required clinicaly in order to maintain the spinal stability. The use of titanium mesh implantation can provide a firm internal fixation folowing resection of tumors. OBJECTIVE:To explore the spinal stability undergoing titanium mesh implantation with internal fixation folowing thoracolumbar tumor resection. METHODS:Twenty-four patients with thoracolumbar tumor admitted at the Central Hospital of Suining City from September 2013 to September 2014 were randomly selected and given tumor resection folowed by titanium mesh implantation with internal fixation. After treatment, patients were folowed up for 1-12 months to observe and analyze the neural functional recovery and spinal stability of the patients. RESULTS AND CONCLUSION:Al the 24 patients successfuly completed the operation treatment, and there was no case of death at the end of folow-up. During the folow-up, patient's clinical symptoms and neural function were significantly relieved, and Frankel classification was significantly improved after treatment. Regular X-ray examination showed that there was no change in the position of titanium mesh and anterior internal fixation system. There was also no titanium mesh colapse, internal fixation fracture and loosening, and the spinal stability was stil excelent. These findings indicate that patients were not changed, and did not appear because the amount of loose, good spinal stability. Resection of thoracolumbar tumors showed that the thoracolumbar spinal reconstruction with titanium mesh implantation combined with internal fixation folowing tumor resection can obtain good clinical effect and excelent biocompatiblity.