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OBJECTIVE： To extablish the method for blood concentration determination of mitoxantrone in rats， and to study the pharamokinetics of mitoxantrone in rats. METHODS： Totally 6 SD rats were collected and given mitoxantrone 5 mg/kg via tail vein. The blood samples 0.3 mL were collected before medication and 5， 10， 20， 40， 60， 120， 240， 480， 720 min after medication. Blood samples were placed in heparinized EP tube， and the plasma was centrifuged and separated. After adding silica gel， the plasma were ground and mixed well， then added into methanol solution containing 0.5 mol/L hydrochloric acid to precipitate protein. After grinding and mixing， the supernatant was centrifuged and dried with nitrogen and then dissolved with mobile phase. HPLC method was adopted to determine the plasma concentration of mitoxantrone. The determination was performed on ZORBAX SB-C18 column with mobile phase consisted of 20 mmol/L ammonium acetate （pH adjusted to 2.0 with hydrochloric acid）-methanol （65 ∶ 35， V/V） at the flow rate of 1.0 mL/min. The detection wavelength was set at 244 nm， and column temperature was 30 ℃. The sample size was 20 μL. Pharmacokinetic parameters were calculated with DAS 3.0 software. RESULTS： The linear range of mitoxantrone were 200-10 000 μg/L （r＝0.999 6， n＝6）. The lower limit of quantitation was 200 μg/L， and the limit of detection was 150 μg/L， respectively. RSDs of intra-day and inter-day precision and stability were all lower than 8.0％ （n＝5， 3， 6， respectively）. The extraction recoveries were （85.64±3.93）％-（92.31±1.68）％ （n＝3）. The recoveries of accuracy test were （93.58±1.42）％-（113.92±2.74）％ （n＝3）. The pharmacokinetic parameters of mitoxantrone were as follows as AUC0-720 min was （5 247.1±474.6.0） μg·h/L； t1 /2z was （24.88±6.94） h； CLZ was （0.46±0.09） L/（h·kg）； Vz was （11.07±2.64） L/kg. CONCLUSIONS： The method has recovery and good repeatability， and is suitable for the determination of blood concentration of mitoxantrone and its pharmacokinetic research.
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OBJECTIVE： To establish a method for the determination of levofloxacin concentration in human pleural effusion， to study its pharmaceutical characteristics. METHODS： Totally 6 patients with infectious pleural effusion received levofloxacin 0.4 g qd intravenous drip. Pleural effusion was collected at 0.5， 1， 2， 4， 8， 12 and 24 hours after administration. After treated with methanol precipitation protein， HPLC was used to determine the concentration of levofloxacin. The determination was performed on Agilent ZORBAX SB-C18 column with mobile phase consisted of methanol-0.02 mmol/L KH2PO4 buffer （containing 0.3％ triethylamine， 70 ∶ 30， V/V at the flow rate of 1.0 mL/min. The detection wavelength was set at 294 nm， and the column temperature was 35 ℃. The sample size was 20 μL. The pharmacokinetic parameters were calculated with WinNonlin 5.2 software. RESULTS： Under this chromatogram condition， retention time of levofloxacin was about 4.9 min， the peak shape was good， the baseline was stable， and the determination of endogenous substances in pleural effusion had no interference. The linear range of levofloxacin were 0.625-20 μg/mL（R2＝0.998 9）. The relative recovery rates were （83.75±1.66）％-（87.73±2.43）％ for low， medium and high concentration samples （n＝3）； RSDs of intra-day were 2.23％-4.96％ （n＝5）； RSDs of inter-day were 4.10％-4.78％（n＝5）； the accuracy ranged （97.76±4.85）％-（100.87±2.25）％（n＝5）； RSD of concentration was no more than 5％ in stability test （n＝3） for low， medium and high quality control sample. The pharmacokinetic parameters of levofloxacin included cmax were （2.21±0.87） μg/mL； AUC0-24 h were （37.31±11.94） μg·h/mL； t1/2 were （4.50±0.21） h. CONCLUSIONS： Established method is simple， reliable and sensitive， and can be used for the determination of levofloxacin concentration in human pleural effusion and its pharmacokinetic study.
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This study was aimed to establish a rapid detection method for timosaponin BⅡ in Anemarrhenae Rhizoma in order to determine its concentration quickly,conveniently and efficiently.The concentration of timosaponin BⅡ in A.Rhizomadetected by HPLC in the Chinese Pharmacopeia was used as the actual measured value.The near-infrared spectroscopy (NIRS) was used to collect the spectrogram of A.Rhizomasamples.The partial least squares (PLS) of TQ Analyst 8.0 were used in the data analysis.Through the pretreatment,wavelength range and principal component number selection,the actual measured value and NIRS information were associated for the establishment of the optimal quantitative analysis model of timosaponin BⅡ.The results showed that the correlation coefficients (R2),root-mean-square error of calibration (RMSEC),root-mean-square error of prediction (RMSEP),root-mean-square error of cross-validation (RMSECV) and the performance index (PI) of the established model were 0.975 15,0.094 2,0.080 0,0.369 20,and 91.0,respectively.It was concluded that the established quantitative analysis model by NIRS with HPLC was able to determine the concentration of timosaponin BⅡ in A.Rhizomaquickly and accurately.
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0.05)except that the tmax of the testing preparation was faster than that of the control drug.The relative bioavailability of the testing drug was(93.83?15.21)%.CONCLUSION:The AUC0～24,AUC0～∞and Cmax of 2 preparations are similar,but there is a significant difference in tmax.
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To establish the determination method of dauricine (Dau) concentration in rats' blood and other biological samples, a reverse-phase HPLC method was adopted. Under the given condition, dauricine could be well separated. The retention time (tR) of Dau and its internal standard,daurisoline were 9.2 and 6.1 respectively. The detection limit was 10-2 mg/ml. The absolute recoveries of all kinds of samples were above 70%, and the relative ones were over 85%. A good liner relationship has been obtained over the entire range of 0.030 to 3.000 mg/L in blood samples and 0.050 to 5.000 mg/L in other tissue samples. The intraday and interday coefficients of variation were below 10%. The results showed that the method can be used for detecting Dau in all kinds of biological samples.
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To establish the determination method of dauricine (Dau) concentration in rats' blood and other biological samples, a reverse-phase HPLC method was adopted. Under the given condition, dauricine could be well separated. The retention time (tR) of Dau and its internal standard,daurisoline were 9.2 and 6.1 respectively. The detection limit was 10-2 mg/ml. The absolute recoveries of all kinds of samples were above 70%, and the relative ones were over 85%. A good liner relationship has been obtained over the entire range of 0.030 to 3.000 mg/L in blood samples and 0.050 to 5.000 mg/L in other tissue samples. The intraday and interday coefficients of variation were below 10%. The results showed that the method can be used for detecting Dau in all kinds of biological samples.
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This article describes the definition of the term TDM (i. e. therapeutic drug monitoring), presents the past history, present status and future prospects of individualized dosing regimen, and emphasizes the role of population pharmacokinetics and one point feedback Bayesian method played in the design of dosing regimen.