人体钙吸收的评价方法

评价人体钙吸收的方法很多。随着科学的进步 ,一些新的研究方法和分析技术相继建立 ,一些老方法得到补充与更新。目前看来 ,稳定性同位素法以其灵敏、准确的特点得到广泛的应用。本文将对此法加以介绍。此外 ,还简要说明了比较常用的药代动力学法、尿增量法及钙平衡法。

特殊生物等效性评价方法介绍

应用药代动力学法来研究全身性吸收药物的生物等效性目前已较为成熟。而一些特殊性的药物,如内源性物质和高变异性药物,其等效性研究需要新的试验设计和统计学方法。

Pharmacokinetics of Oxiracetam in Healthy Volunteers

Aim To study the pharmacokinetics of oxiracetam after single and multipleintravenous administrations in healthy volunteers. Method A HPLC method was used to determine theserum concentration of oxiracetam after intravenous single dose and daily dose of 2 000 mg for 7 din ten Chinese healthy volunteers. Pharmacokinetic analysis was carried out using Drug And Statisticsoftware. Results The AUC_(0-12), AUC_(0-∞), K_e, t_(1/2), MRT after a single dose of 2 000 mgoxiracetam were 256.26 ± 16.84 μg·mL^(-1)·h, 276.74 ±18.11 μg·mL^(-1)·h, 0.18 ±0.03 h^(-1),3.84±0.64 h, and 4.39 10.39 h, and after multiple doses of oxiracetam were 259.36 ±25.43μg·mL^(-1)·h, 285.59 ±27.38 μg·mL^(-1)·h, 0.17 ±0.04 h^(-1), 4.14 ± 0.82 h, and 4.87 ±0.69 h, respectively. Conclusion The pharmacokinetic parameters of oxiracetam do not differremarkably after single and multiple intravenous administration and there is accumulation in serumafter 2 000 mg multiple intravenous administration once a day fof 7 d.

Pharmacokinetics of Ferulic Acid in Rabbits with BloodStasis

To test and study the Syndrome and Treatment Pharmacokinetics (S & TRK),we studied the pharmacokinetics of ferulic acid in healthy and blood stasis (microcirculation dysfunction)rabbits by RP-HPLC. After a single intravenous injection offenilic acid(5mg/kg)to healthy and blood stasis rabbits, compartment model of ferulic acid serum concentration was fitted and then pharmacokinetic parameters were calculated with a MCPKP program on a COMPAQ 386 compute Important parameters are as follows: In healthy rabbits V_B=0.9525±0.0211 L/kg,V_1=0.2462±0.0381 L/kg, CL_B=1.8133±0.9512 L/h·kg, T_(1/2β)=0.3639±0913, AUC=2.7566±0.8232 μg·h/ml; In blood stasis rabbits V_B=0.7882±0.0321 L/kg,V_1=0.1966±0.0537 L/kg,CL_B=0.8820±0.5481 L/h·kg,T_(1/2β)=0.6193±0.1216 h, AUC=5.6690±2.3541μg·h/ml.Through this experiment we found the sig-nificant differences in the FA's pharmacokinetic parameters between healthy and blood stasis rabbits.The results obtained correspond with S & TPK.

Pharmacokinetics of Scutellarin in Dogs

Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the mean plasma concentration-time curve was plotted and pharmacokinetic parameters were calculated by program 3p87. Resu;ts The concentration-time curve of scutellarin could be fitted to three-compartment model with T1/2 pi, T1/2 α and T1/2 β being 1.05 ± 0.80 min, 6.99 + 2.76 min and 51.61 + 28.78 min, respectively, Vc being 880.1 + 508.3 mL, CL being 189.6 + 53.8 mL@ min- 1, and AUC0-90 and AUC0-∞ being 574.43 + 133.95 μg@ min@ mL - 1 and 599.34 ± 132.00μg@ min@mL- 1, respectively. Conclusion The fact that the concentrations of scutellarin in plasma declined rapidly after the medication suggested that the T1/2 of scutellarin should be taken into account in drug administration and preparation development.

High Resolution Determination of Ondansetron in Human Plasma by HPLC and Pharmacokinetics of Orally Disintegrating Tablets

Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.

Determination of Sulphonylurea Glimepiride in Dog Serum by RP-HPLC with Pre-column Derivatization

Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.

Pharmacokinetics of Active Metabolite of Prulifloxacin in Healthy Chinese

Aim To investigate the pharmacokinetics of NM394 （an active metabolite of prulifloxacin） and evaluate the dose relationship and accumulation characteristics after single and multiple doses of prulifloxacin. Methods Twelve healthy volunteers were given 132.1 mg, 264.2 mg, and 396.3 mg of prulifloxacin tablets in a randomized 3 × 3 crossover design test for single doses trial. With one-week washout period, 264.2 mg of prulifloxacin tablets were given for multiple doses trial. NM394 in plasma was determined by a sensitive HPLC method and its pharmacokinetic parameters were analyzed and evaluated by Drug and Statistics saftware （version 1.0）. Results The Cmax, Tmax, t 1/2, AUC0-24, and AUC0-∞ of NM394 after single doses of 132.1 mg, 264.2 mg, and 396.3 mg of prulifloxacin tablets were 0.64 ± 0.25 μg· mL^-1, 1.06 ± 0.35 μg· mL^-1, and 1.45 ± 0.44 μg· mL^-1 , respectively; Tmax 0.94±0.22 h, 1.02±0.17 h, and 0.98±0.23 h, respectively; t 1/2 8.37±0.70 h, 7.70±0.82 h, and 7.78 ± 0.77 h, respectively; AUC0-24 2.93 ± 0.78 μg· mL^-1· h, 4.39 ± 1.05 μg· mL^-1· h, and 5.55± 1.32 μg·mL^-1 ·h, respectively; AUC0-∞ 3.32±0.84 μg·mL^-1 ·h, 4.82± 1.06 μg·mL^-1 ·h, and 6.10 ± 1.38 μg·mL^-1· h, respectively. And the Cmax, Tmax, t,1/2, AUC0- 24, and AUC0-∞ after multiple doses of 264.4 mg prulifloxacin tablets were 1.20 ± 0.33 μg· mL^- 1, 0.67 ± 0.12 h, 7.38 ± 1.03 h, 5.58 ± 1.25 μg· mL^-1·h, and 6.09 ± 1.24 μg· mL^-1· h, respectively. Conclusion The Cmax and AUC of NM394 are in high correlation with given prulifloxacin doses. There are no differences in pharnacokinetic characteristics of NM394 between single and multiple doses. No accumulation in plasma is observed after multiple doses of 264.2 mg per day for 7 d.

Determination of Lansoprazole by Direct Injection of Plasma and High Performance Liquid Chromatography with Column Switching

High performance liquid chromatography with column switching has been developed for the determination of lansoprazole in plasma. The plasma samples were injected onto a pretreatment column packed with LiChromprep RP2 (25～40 mm) after simple dilution with distilled water. Distilled water was used to wash out protein and other polar components in plasma. After switching, the concentrated lansoprazole was eluted in the backflush mode onto a Shimpack CLC ODS column with methanol 0 2 mol·L 1 ammonium acetate (65:35) as mobile phase. Purge solutions were used for clean up and for regenerating the pretreatment column. The method showed good precision and recovery. The detection limit was 0 005 mg·L -1 plasma. The RSD’s (intra and interday) were less than 2 5% and 5 3% respectively. The method has been successfully used to determine pharmacokinetics of lansoprazole in Chinese volunteers.

Rational prescription of drugs within similar therapeutic or structural class for gastrointestinal disease treatment: Drug metabolism and its related interactions

AIM:To review and summarize drug metabolism and its related interactions in prescribing drugs within the similar therapeutic or structural class for gastrointestinal disease treatment so as to promote rational use of medicines in clinical practice.METHODS:Relevant literature was identified by performing MEDLINE/Pubmed searches covering the period from 1988 to 2006.RESULTS:Seven classes of drugs were chosen,including gastric proton pump inhibitors,histamine H2-receptor antagonists,benzamide-type gastroprokinetic agents,selective 5-HT3 receptor antagonists,fluoroquinolones,macrolide antibiotics and azole antifungals.They showed significant differences in metabolic profile(i.e.,the fraction of drug metabolized by cytochrome P450(CYP),CYP reaction phenotype,impact of CYP genotype on interindividual pharmacokinetics variability and CYP-mediated drug-drug interaction potential).Many events of severe adverse drug reactions and treatment failures were closely related to the ignorance of the above issues.CONCLUSION:Clinicians should acquaint themselves with what kind of drug has less interpatient variability in clearance and whether to perform CYP genotyping prior to initiation of therapy.The relevant CYP knowledgehelps clinicians to enhance the management of patients with gastrointestinal disease who may require treatment with polytherapeutic regimens.

Dried-leaf Artemisia annua: A practical malaria therapeutic for developing countries?

Artemisinin from the plant Artemisia annua （A. annua） L., and used as artemisinin combination therapy （ACT）, is the current best therapeutic for treating malaria, a disease that hits children and adults especially in developing countries. Traditionally, A. annua was used by the Chinese as a tea to treat “fever”. More recently, investiga-tors have shown that tea infusions and oral consumption of the dried leaves of the plant have prophylactic and therapeutic effcacy. The presence of a complex matrix of chemicals within the leaves seems to enhance both the bioavailability and effcacy of artemisinin. Although about 1000-fold less potent than artemisinin in their antiplasmodial activity, these plant chemicals are mainly small molecules that include other artemisinic compounds, terpenes （mainly mono and sesqui）, favonoids, and polyphenolic acids. In addition, polysaccharide constituents of A. an-nua may enhance bioavailability of artemisinin. Rodent pharmacokinetics showed longer T？ and Tmax and greater Cmax and AUC in Plasmodium chabaudi -infected mice treated with A. annua dried leaves than in healthy mice. Pharmacokinetics of deoxyartemisinin, a liver metabolite of artemisinin, was more inhibited in infected than in healthy mice. In healthy mice, artemisinin serum levels were 〉 40-fold greater in dried leaf fed mice than those fed with pure artemisinin. Human trial data showed that when delivered as dried leaves, 40-fold less artemisinin was required to obtain a therapeutic response compared to pure artemisinin. ACTs are still unaffordable for many malaria patients, and cost estimates for A. annua dried leaf tablet production are orders of magnitude less than for ACT, despite improvements in the production capacity. Considering that for 〉 2000 years this plant was used in traditional Chinese medicine for treatment of fever with no apparent appearance of artemisinin drug resistance, the evidence argues for inclusion of affordable A. annua dried leaf tablets into the arsenal of drugs to combat malaria and other artemisinin-susceptible diseases.

Determination of 2-Amino-6-Cyclopropylamino-9-(2,3-Dideoxy-β-D-glyceropent-2-enofuranosyl)purine in Rat Plasma,Urine and Liver Homogenates by High Performance Liquid Chromatography

Aim To develop a simple and specific high-performance liquid chromatographic(HPLC) method, suitable for the pharmacokinetic studies in vivo, to determine the concentrations of2-amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuranosyl)purine (Cyclo-D4G, IMGprodrug) in rat plasma, urine and liver homogenates. Methods Chromatography was performed with C-18Hypersil ODS column and a mobile phase of 7% (v/v) acetonitrile in phosphate buffer, pH 7.40, withUV detection at 283 nm. Results The average extraction recovery of Cyclo-D4G in rat plasma and urinewas 100.1% over its linear range of 0.5 - 80 μg·mL^(-1). The accuracy of the assay was 99.4% .The intra-and inter-day RSDs were less than 9.0% . Conclusion The analytical method was found to beapplicable, reliable and suitable for pharmacokinetic studies.

Pharmacokinetics and Biodegradation of Chitosan in Rats

Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate(FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 k Da. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

A high performance liquid chromatography method for the quantitative determination of ribavirin in human plasma and its application in a pharmacokinetics study

The clinical pharmacokinetics of ribavirin after a single oral dose of 600 mg ribavirin tablets in healthy Chinese volunteers was studied. A rapid and simple high performance liquid chromatography （HPLC） method was developed to determine the ribavirin concentration in human plasma. C18 column was used for separation with a column temperature of 25℃, the mobile phase was ultrapure water adjusted to pH 3 with acetic acid at the flow rate of 1 mL/min, and the detection wavelength was set at 207 rim. The linear range of the standard curves was 50.4-2016.0 ng/mL and the lower limit of quantification （LLOQ） was 50.4 ng/mL. The relative recoveries of ribavirin were more than 90% in plasma. The RSD of the intra-day precision was less than 10% and that of inter-day was less than 15%. The pharmacokinetic parameters of ribavirin were calculated by WinNonlin. Results indicated that the two-compartment model was a better model for describing the pharmacokinetics profile of ribavirin than one-compartment model. The AUC0-t was 10807.8 h.ng/mL, the CL/F was 64879.5 mL, and the Cmax was 525.1 ng/mL. These results provided the experimental data for the development of ribavirin dosage form.

HPLC-UV method with solid-phase extraction for the quantitative determination of biapenem in human plasma and its application in pharmacokinetic study

Biapenem, a new parenteral carbapenem, has been widely used for treating bacterial infections. A simple, effective and accurate method based on solid-phase extraction （SPE） and HPLC was developed for the quantitative determination of biapenem in human plasma. Stability and feasibility of the method was validated through a series of experiments. Using Vitamin B6 as an internal standard, analyte was separated on a Capcell Pak C18 column after SPE on Oasis hydrophilic-lipophilic balance （HLB） cartridge. The mobile phase was comprised of 0.05 mol/L NaH2PO4 （pH 5.7） and methanol （98：2, v/v） at a flow rate of 1.0 mL/min. Ultraviolet absorbance was measured at 300 nm. The calibration curve was linear in the concentration range of 0.04-50.00 μg/mL, and the lower limit of quantification was as low as 0.04 μg/mL. Recovery rates of biapenem at 0.10, 5.00, and 25.00 μg/mL were about 70%. The validated method has been successfully applied for quantifying biapenem in human samples and a pharmacokinetic study of 12 healthy volunteers who received three different doses （150, 300 and 600 mg） of biapenem by intravenous infusion. Our method has featured good accuracy and precision, and the processed sample was stable. Therefore, it can be propagated for clinical use.

Study on pharmacokinetic and tissue distribution ofisovitexin in rats by HPLC

An HPLC method for the determination of isovitexin in rat plasma and different tissues was developed.The separation was achieved on a C_（18）column with a mobile phase consisting of methanol-1% acetum（40：60,v/v）at a detection wavelength of 338 nm and a column temperature of 30℃.Rutin was chosen as the internal standard.The linear range of the standard curves was 0.20-128.75μg/mL in the plasma and 0.024-3.09μg/mL in the tissues.The LOQ was 0.19μg/mL in the plasma and 0.024μg/mL in the tissues.The relative recoveries of isovitexin ranged from 93% to 105% in the plasma and 87% to 112% in the tissues.The intra-and inter-day precisions were all below 8%.The pharmacokinetics and tissue distribution of isovitexin in rats were studied with the method.Blood samples were collected at fixed time intervals after the i.v.injection of isovitexin at a dosage of 18.75,3.75 and 0.75 mg/kg;the tissue samples（brain,liver,kidney,heart,lung,spleen and ovary）were obtained at 10,30,and 60 min after the i.v.injection of isovitexin at a dosage of 18.75 mg/kg.The pharmacokinetics of the isovitexin in three different dosages in the rats fit the two-compartment open model.The isovitexin displayed linear dynamics in the dosage range of 0.75-18.75 mg/kg.The mean value of t_（1/2α）was 1.54-1.84 min,and t_（1/2β）was 36.94-46.27 min at the three dosages.The tissue distribution study showed that the sequence of tissue drug concentration from high to low was kidneyliverlung≈ovaryheart≈spleenbrain.

A method for the quantitative determination of glycyrrhetic acid in plasma by LC-MS/MS and its application in a pharmacokinetic study of ammonium glycyrrhetate

A simple and rapid liquid chromatography-tandem mass spectrometry（LC-MS/MS）method was developed and validated for the quantitative determination of glycyrrhetic acid（GA）,metabolite of glycyrrhizin and glycyrrhetate,in human plasma.GA and internal standard（IS,thiamphenicol）were separated on a C_（18）column by elution with acetonitrile-ammonium acetate solution（5 mmol/L）（70：30,v/v）after a simple liquid-liquid extraction with ethyl acetate.The flow rate was 0.8 mL/min. They were detected by tandem mass spectrometry in the negative ion multiple reaction monitoring（MRM）mode with ion transitions of m/z 469.3→355.3 for GA and m/z 354.1→185.0 for IS.The calibration curve was linear over GA concentration range of 0.5-500 ng/mL（r^20.99）,with intra-and inter-day precisions（RSD）of less than 7.1%,and mean extraction recovery of 74.3%. The method was used for the pharmacokinetic study of ammonium glycyrrhetate after its oral administration of a single dose of 75 mg ammonium glycyrrhetate tablet in humans.The main pharmacokinetic parameters of GA were as follows：AUC_（0-t） （3457.26±1999.01）ng·h/mL;AUC_（0-∞）（3708.85±2428.36）ng·h/mL;MRT_（0-t）（19.69±4.03）h;MRT_（0-∞）（22.83±8.45）h;t_（1/2）Z （11.71±7.77）h;T_（max）（13.40±4.84）h;CLz/F（29.17±19.82）L/h;Vz/F（487.38±518.07）L;C_（max）（215.85±99.88）ng/mL.

Determination of biapenem in human plasma and urine by a simple HPLC method for its pharmacokinetics study

A simple high-performance liquid chromatography （HPLC） method was established and subsequently used to study the pharmacokinetics of biapenem in healthy volunteers. Chromatography separation was carried out using a C18 reverse-phase column with an isocratic mobile phase consisting of 0.05 M ammonium acetate-methanol, either for plasma （94：6, v/v, and flow rate 1.0 mL/min） or for urine samples （97.5：2.5, v/v, flow rate 1.5 mL/min）. The UV detector was set at 300 nm. The assay was linear over the range of 0.25 mg/L-50 mg/L for plasma samples and 0.50 mg/L-200 mg/L for urine samples. The intra-day and inter-day RSD values were lower than 2.8% and 4.6%, respectively, for biapenem in plasma, 2.4% and 2.5%, respectively, for biapenem in urine. Biapenem was stable at room temperature for up to 6 h in plasma and 8 h in urine when MOPS was added immediately after sample collection. An intravenous single dose of 600 mg biapenem was administered to 12 healthy male volunteers. The pharmacokinetic parameters were calculated by Winnonlin with a noncompartment model. The pharmacokinetic parameters were obtained as following： Cmax 37±6 mg/L, t1/2 1.27±0.21 h, AUC0-8h 56±8 mg/L/h, and AUC0-∞57±8 mg/L/h. The accumulated urine excretion rate in 24 h was 58%±5%. The established HPLC method was validated and suitable for the pharmacokinetic study of biapenem.

Effects of co-administraton of neferine and doxorubicin on the pharmacokinetics of doxorubicin

Doxorubicin is one of the anthracycline anti-neoplastic drugs widely used to treat leukemia, liver, breast, and ovarian cancers and other solid tumors. However, its clinical applications have been limited by its serious cardio-cytotoxic effects. The aim of this study was to investigate the effect of neferine, a bisbenzylisoquinoline alkaloid extracted from the green embryo in the mature lotus seed, on the pharmacokinetics of doxorubicin. The levels of doxorubicin in plasma and tissues were measured using the high performance liquid chromatography（HPLC） method. The chromatographic separation was completed on a reversed-phase C18 column using acetonitrile–phosphate buffer（30：70, v/v） as the mobile phase at a flow rate of 1 mL /min and ultraviolet detection wave length was set at 233 nm. The pharmacokinetic study found that the co-administration of neferine and doxorubicin significantly affected the pharmacokinetics of doxorubicin. There were evident changes in area under the curve（AUC）, clearance（CL） and t1/2β in group of pretreatment neferine as compared with those in group treated with doxorubicin alone. Tissue distribution analysis showed that the concentrations of doxorubicin distributed to heart, liver and kidney were statistically significant higher in group of pretreatment with neferine plus doxorubicin than those in the doxorubicin alone-group at 0.5 h and 2 h after drug administration, respectively. While the doxorubicin concentrations in spleen and lung drug were slightly increased in the group of pretreatment with neferine plus doxorubicin as compared to that of group of doxorubicin alone, the difference between two groups were not statistically significant. Therefore, the dose of doxorubicin needs to be taken into consideration when it is administrated in combination with neferine.

Development of high-performance liquid chromatography assay for pharmacokinetic analysis of KCNQ/M-channel opener QO58-lysin in rat plasma

A simple, reliable and efficient assay for quantitative analysis of a novel Kv7/KCNQ/M-channel opener QO58-lysin in rat plasma was developed using high-performance liquid chromatography（HPLC） with UV detection. Separation of compound QO58-lysin from plasma was achieved using a reverse-phase C18 column with a mobile phase of 0.2 M ammonium acetate in H2O–acetonitrile（40：60, v/v） with nitrendipine used as an internal standard（IS）. The retention times of QO58-lysin and the IS in rat plasma were 3.8 and 5.4 min, respectively. Calibration curve was linear ranging from 0.1 to 120 μg/mL with correlation coefficient（r2） of 0.9996. The lower limit of quantification was 0.1 μg/mL. Accuracy, precision, recovery as well as stability were all within acceptable criteria according to Food and Drug Administration（FDA） guidelines. This validated assay was successfully applied to determine the pharmacokinetics of QO58-lysin administered intravenously（10 mg/kg） in SD rats. The distribution and elimination half-life of QO58-lysin in plasma was（0.25±0.16） h and（2.15±0.12） h, respectively.