ABSTRACT
OBJECTIVE:To establish physiological pharmacokinetic (PBPK) model of cefdinir in healthy volunteers,and to predict pharmacokinetic process of cefdinir in volunteers after oral administration. METHODS:Using“toubao dini”“cefdinir”“logP”“pKa”as keywords,related literatures about physico-chemical constants of cefdinir were retrieved from CNKI,ScienceDi-rect,PubMed and other databases;according to related guidelines and preliminary clinical trial plan of FDA,GastroPlusTM 8.6 soft-ware was used to establish PBPK model of oral administration of cefdinir;the effectiveness of the model was evaluated by multiple error. The model was used to simulate the absorption of cefdinir in the gastrointestinal tracts. The bioequivalence of test preparation and reference preparation were evaluated through single and population(n=500)simulation tests using cmax and AUC0-∞ of cefdinir reference preparation (capsule and granular formulation) as factors when release rate t85%=15 min (i.e. accumulatively released 85% within 15 min). RESULTS:The blood concentration-time curves of cefdinir predicted by PBPK model fitted well with mea-sured value(R2≥0.95);the pharmacokinetic parameters(cmax,tmax,AUC0-∞)were close to measured results,and the multiple er-rors were less than 2. After oral administration,cefdinir was mainly absorbed by the intestinal tract (45.6%),especially by seg-ment 1 of jejunum(14.8%);the absorption amount was significantly lower than the release amount of absorption site,and reached the maximal value(about 40%)within 4 h. The results of single simulation test showed that there was no statistical significance in cmax and AUC0-∞ between cefdinir test and reference preparations (P>0.05). The results of population simulation test showed that the relative bioavailability of cefdinir test particle and test capsule respectively were 99.01%-102.99% and 97.60%-105.90%;90%CI of cmax and AUC0-∞ values were within 80%-125% of reference preparation. CONCLUSIONS:The PBPK model is accurate and reliable in this study,can provide reference for pharmacokinetic study and bioequivalence evaluation of cefdinir preparations. Test preparation and reference preparation are equivalent.
ABSTRACT
Objective To evaluate postprandial pharmacokinetics and bioequivalence of two preparations of cefdinir capsules in Chinese healthy volunteers. Methods In a two-way cross-over study, 24 healthy male volunteers were divided into two groups randomly and a single dose of cefdinir capsules of test and reference preparation were administered orally, respectively.The concentration in plasma was determined by LC-MS/MS. Pharmacokinetic parameters and bioequivalence were calculated and evaluated by DAS. Results The main pharmacokinetic parameters of test and reference were as follows: AUCt (4.35±1.09) μg??h??mL-1 and (4.12±1.22) μg??h??mL-1, AUC0-∞(4.53±1.12) and (4.53±1.73) μg??h??mL-1, t1/2 (1.74±0.29) h and (2.13±1.65) h, tmax(4.44±0.86) h and (4.54 ±1.16) h, Cmax(900±250) ng??mL-1 and (876±269) ng??mL-1 . Conclusion The test and reference preparation of cefdinir capsules are bioequivalent.