灯盏花素缓释片在兔体内的绝对生物利用度

Absolute bioavailability of breviscapine sustained release tablet in rabbit

目的测定兔静注灯盏花素注射剂25 mg及兔口服灯盏花素缓释片120 mg后血浆中野黄芩苷的浓度,研究2种制剂的药动学参数和缓释片的绝对生物利用度。方法采用C_8固相萃取法预处理血浆样品,兔静注和口服灯盏花素后的血药浓度分别采用高效液相色谱-紫外检测法和高效液相色谱-质谱检测法测定。结果兔静注灯盏花素注射剂后的药-时曲线符合三室模型。兔口服灯盏花素缓释片后的药-时曲线难以用现有的房室模型拟合,6只兔的药-时曲线及药动学参数差异较大。经剂量校正,口服给药的绝对生物利用度F为(0.18±0.15)%。结论兔口服灯盏花素缓释片后的绝对生物利用度很低。

AIM To investigate the pharmaeokineties of scutellarin after intravenous injection （iv） and oral administration of breviscapine to rabbits and to study the absolute bioavailability of breviscapine sustained release tablet in rabbits. METHODS Scutellarin and internal standard （IS） baicalin were extracted from plasma by solid-phase extraction using C8 cartridges. The concentration of scutellarin in rabbit plasma after intravenous injection of breviscapine injection was determined by a HPLC-ultraviolet （HPLC-UV） method, and that after oral administration of breviscapine sustained release tablet was determined by an HPLC-mass spectrometry （MS） method. RESULTS After intravenous injection of breviscapine injection 25 mg, the concentration-time profiles were fitted to a three-compartment model, and the main pharmacokinetic parameters were as follows： t1/2pi（0.04 ± 0.01 ）h, t1/2α（0.32 ±0.23）h, t1/2β（3.3 ±1.1） h, and AUC0→5h（ 12.6 ± 2.3）mg· h· L^-1. After oral administration of sustained release tablet 120 mg, the concentration-time profiles could not be described by classical compartment model, and the main pharmacokinetic parameters were as follows-ρmax （ 12.7 ±12.4） μg· L^-1, tmax （9. 3 ± 7.3 ） h and AUC0→24h （ 110.9± 79.0） μg·h· L^-1. The absolute bioavailability （F） of oral administration was only （0.18 ±0.15） %. CONCLUSION The absolute bioavailability of breviscapine sustained release tablet in rabbits is very low.