| Tenofovir Disoproxil Fumarate (TDF) is a new kind of nucleoside reverse transcriptase inhibitors, used in the treatment of adult human immunodeficiency virus (HIV) infection or Hepatitis B virus (HBV) infection. And TDF is a prodrug of tenofovir, which taking effect in the body. Because of the poor oral absorption of tenofovir, made into ester can improve the cellular uptake by the characteristics of high solubility and low permeability. This study was designed to control the quality of TDF mainly according to Pharmacopoeia and some related regulayions. And the pharmacokinetic study was carried out by oral administration of single dose of low, medium and high doses according to related articles. 1. Studies on quality control of TDF raw medicineThe quality research of TDF raw material drug mainly includes characters, physicochemical properties, identification, inspection and assay.The characters and physicochemical properties of the study showed that TDF is White crystalline powder, odorless, freely dissolved in methanol, slightly soluble in ethanol, acetone, very slightly soluble in water and ethyl acetate, hardly soluble in methylene chloride, and the specific rotation(calculated on the basis of anhydrous) is-16°to-20°.TDF was identified by the method of high performance liquid chromatography (HPLC), infrared spectroscopy (IR) and ultraviolet spectroscopy (UV). The results show that TDF has maximum absorption at 260 nm, the retention time was identical between main peak of reference substances and test samples of GDH and fumaric acid, and the characteristics of IR map of reference substances and test samples were consistent.Inspection:the moisture, ignition residue, heavy metals, granularity, differential scanning calorimetry, enantiomers, related substances and residual organic solvents. Test results shows that the moisture was with 1.0%, ignition residue no more than 0.2%, heavy metals didn’t exceed twenty millionths, but exceed ten millionths, methanol solution was clear and colorless, granularity no more than 20%, endothermic peak between 114℃-118℃, (R)-enantiomer content not less than 99.0%, six impurities, Tenovion Mono-POC PMPA、 Tenofovir isoproxil isopropyl Fumarate、DEC-POC PMPA Fumarate、Tenofovir Disoproxil Isopropoxycarbonyl and Tenofovir Disoproxil Dimer, didn’t exceed their limits and total impurity didn’t exceed 2.5%, the amount of acetone, isopropanol, dichloromethane, isopropyl ether, ethyl acetate and N,N-dimethyl formamide, chlorine methyl isopropyl carbonate, N-methyl pyrrolidone didn’t exceed the limit value of 0.5%,0.5%,0.06%,0.1%,0.5%,0.088, 0.3%and 0.053%, conform to the rules.Assay:High performance liquid chromatography (HPLC) method were established for determining the content of TDF and fumaric acid, the results showed that the content of TDF raw medicines was between 98%-98%, and the content of fumaric acid was between 17.5%-19.0%.2. Pharmacokinetic study of TDF raw medicineA sensitive and rapid LC-MS/MS method was developed and established for the quantitative analysis of biological samples of tenofovir in SD rats. In this study, the pharmacokinetics characteristic of 15mg/Kg,30mg/Kg 60mg/Kg were studied in the single dose oral administration of the TDF raw medicine. We use non-compartment model to calculate and estimate the pharmacokinetic parameters of TDF raw medicine.The elimination half-time(t1/2) were 10.71±1.88h、11.64±2.98h、10.11±2.34h, mean residence time(MRT) were 10.29±1.41h.10.73±2.19h.9.42±1.72h, the peak concentration(Cmax) were 1083.89±107.11 ng/mL.1612.06±109.20 ng/mL.1928.03±195.49 ng/mL, AUG0-24 were 2311.45±269.99 ng.h/mL.3642.51±459.11 ng.h/mL.5428.49±1260.80 ng.h/mL, AUC 0-∞ were 2678.06±244.53 ng.h/mL.4241.86±377.23 ng.h/mL.6114.42±1150.53 ng.h/mL. AUCo-24 and Cmax of tenofovir were positively correlated with the dose of 15 mg/Kg.30mg/Kg.60mg/Kg and the correlation coefficients which were R2=0.7916 and R2=0.7820, respectively. |
