Determination of piceid in rat plasma and tissues by high-performance liquid chromatographic method with UV detection

A rapid, sensitive and selective HPLC method was developed and validated for determination of piceid in rat plasma and tissues. The drug was isolated from plasma and tissues by a simple protein precipitation procedure. Chromatographic separation was performed on a C(18) column with acetonitrile-water (26:74, v/v) as mobile phase. The method was successfully applied to the pharmacokinetics and tissue distribution research after oral administration of a 50 mg/kg dose of piceid to healthy male Wistar rats. The pharmacokinetic parameters showed that piceid was quickly absorbed, distributed and eliminated within 4 h after oral administration. The tissue distribution results showed that, at 10 min, the concentrations of piceid in most tissues reached peak level except in heart and testis. The highest level of piceid was found in stomach, then in small intestine, spleen, lung, brain, testis, liver, kidney and heart. The amount of piceid in testis and heart reached the peak level at 30 min. At 120 min, the amount of piceid in all tissues decreased to a low percentage of the initial concentration. Piceid was absorbed throughout the gastrointestinal tract with considerable absorption taking place in the stomach and small intestine. There was no long-term accumulation of piceid in rat tissues.     

The determination of raloxifene in rat tissue using HPLC

We report a rapid and reliable HPLC-UV method for determination of raloxifene, a kind of selective estrogen receptor modulator (SERM), in rat tissue. Proteins were precipitated by adding 200 microL of acetonitrile and 50 microL of methanol to 100 microL of the tissue homogenates, following vortex mixing and centrifugation. Separation was carried out on a reversed-phase C(18) column (150 x 4.6 mm, 5 microm) with a mobile phase of acetonitrile:0.05 m ammonium acetate (pH 4.0 +/- 0.1; 33:67, v/v) at a flow rate of 1.0 mL/min. The UV detection wavelength was set at 289 nm and the temperature of column was kept at 23 degrees C, without interference from endogenous tissue compounds. The calibration curve was linear from 0.0125 to 10.0 microg/mL with correlation coefficient of over 0.994, while the limit of quantification was 0.008 microg/mL. The intra- and inter-day coefficients of variation were less than 10% (RSD). The recovery of assay was between 95.8 and 104.5%. Furthermore, the method was used to measure the concentration of raloxifene in rat tissue after a simple oral dose. The highest level was observed in liver, lung, spleen, then heart and kidney. The lowest level was found in brain. These results suggest that raloxifene distributes rapidly and moderately into tissues such as liver, lung and spleen.     

Autoradiographic study on the distribution of suprofen in rats of both sexes

The tissue distribution of 14C-labeled DL-2-(4-(2-thienylcarbonyl) phenyl) propionic acid (suprofen) after po administration was studied in male, female, and pregnant rats by whole-body autoradiography. 14C localized rapidly in such highly vascularized tissues as liver, kidney, and lung as well as heart in rats of both sexes, but no significant uptake was found in the central nervous system. About half of the 14C in the liver and kidney was found to be unchanged suprofen; smaller amounts of 2-(4-(2-thienylhydroxymethyl)phenyl)propionic acid and 2-(4-carboxyphenyl)propionic acid were also detected. In pregnant rats, a low level was found in the uterus and placenta; the drug penetrated the fetuses to only a limited degree. No appreciable radioactivity was found in rat tissues 24 h after dosing.     

Study of tanshinone IIA tissue distribution in rat by liquid chromatography-tandem mass spectrometry method

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for determining tanshinone IIA in rat tissues. After a single step liquid-liquid extraction with diethyl ether, tanshinone IIA and loratadine (internal standard) was subjected to LC/MS/MS analysis using positive electro-spray ionization under selected reaction monitoring mode. Chromatographic separation of tanshinone IIA and loratadine was achieved on a Hypersil BDS C(18) column (i.d. 2.1 x 50 mm, 5 microm) with a mobile phase consisting of methanol-1% formic acid (90:10, v/v) at a flow rate of 300 microL/min. The intra-day and inter-day precision of the method were less than 10.2 and 12.4%, respectively. The intra-day and inter-day accuracies ranged from 99.7 to 109.7%. The lowest limit of quantification for tanshinone IIA was 1 ng/mL. The method was applied to a tanshinone IIA tissue distribution study after an oral dose of 60 mg/kg to rats. Tanshinone IIA tissue concentrations decreased in the order of stomach > small intestine > lung > liver > fat > muscle > kidneys > spleen > heart > plasma > brain > testes. Tanshinone IIA still could be detected in most of the tissues at 20 h post-dosing. These results indicate that the LC/MS/MS method was rapid and sensitive to quantify tanshinone IIA in different rat tissues.     

Tissue distribution study of columbianadin and its active metabolite columbianetin in rats

Columbianadin, one of the main bioactive constituents of the roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan, has been found to possess obvious pharmacological effects in previous studies. In this study, a valid and sensitive reverse‐phase high‐performance liquid chromatography (RP‐HPLC) method was established and validated for the determination of columbianadin (CBN) and its active metabolite columbianetin (CBT) in rat tissue samples. Sample separation was performed on an RP‐HPLC column using a mobile phase of MeOH–H₂O (75:25, v/v) at a flow rate of 1.0 mL/min. The UV absorbance of the samples was measured at the wavelength 325 nm. The calibration curves for CBN were linear over the ranges of 0.5–20 µg/g for brain, testes and muscle, 1.0–10.0 µg/g for stomach and intestine, and 0.2–20.0 µg/g for heart, liver, spleen, lung and kidney. The calibration curves for CBT were linear over the ranges of 0.5–25 µg/g for stomach and intestine, and 0.1–10.0 µg/g for heart, liver, spleen, lung and kidney. The analysis method was successfully applied to a tissue distribution study of CBN and CBT after intravenous administration of CBN to rats. The results of this study indicated that CBN could be detected in all of the selected tissues after i.v. administration. CBN was distributed to rat tissues rapidly and could be metabolized to CBT in most detected tissues. Of the detected tissues, heart had the highest uptake of CBN, which suggested that heart might be one of the main target tissues of CBN. Concentrations of CBT were obviously higher in the digestive system than in other assayed tissues. The information provided by this research is very useful for gaining knowledge of the capacities of CBN and CBT to access different tissues. Copyright © 2015 John Wiley & Sons, Ltd.     

Determination of dehydrodiisoeugenol in rat tissues using HPLC method

Dehydrodiisoeugenol (DDIE) is a bioactive neolignan from the seeds of Myristica fragrans Houtt., which exhibits good anti-inflammatory activity. A rapid and simple high-performance liquid chromatographic (HPLC) method has been developed for the determination of DDIE in rat tissues after intravenous administration. The tissue samples were processed by liquid-liquid extraction. The analyses were successfully carried out on a Diamonsiltrade mark ODS C18 column (250 x 4.6 mm i.d., 5 microm) equipped with a C18 guard column (8 x 4.6 mm i.d., 5 microm). The mobile phase was the system of methanol-water (4:1, v/v). The UV detection was set at 270 nm. The calibration curves were linear from 0.4 to 200.0 microg/g with the correlation coefficients (r(2)) greater than 0.998. The intra- and inter-day precisions in quality control samples were less than 10% and the accuracies were in the range 85.4-110.3%. The average recoveries from all the tissues were between 84.4 and 106.0%. This assay method has been successfully used to study the tissues distribution of DDIE in rats after intravenous administration. The result suggests that DDIE is distributed to rat tissues rapidly with possibly greater initial concentrations in liver and brain than in other tissues.     

Distribution study of cisplatin in rat kidney and liver cancer tissues by using liquid chromatography electrospray ionization tandem mass spectrometry

A sensitive and rapid liquid chromatography positive ion electrospray ionization tandem mass spectrometric (LC/ESI‐MS/MS) method has been developed and validated for the quantitative determination and distribution of cisplatin (CP) in kidney and liver tissues after intravenous administration of drug to adult male Sprague Dawley rats. Oxaliplatin (OXP) was used as an internal standard. The tissue samples were homogenized and extracted using conventional liquid–liquid extraction method with phosphate buffer containing ethyl acetate and then subjected to LC‐MS analysis. The chromatographic separation was achieved on an Agilent ZORBAX SB C‐18 column (50 × 2.1 mm, 1.8 µm) using the mobile phase consisting of 0.1% formic acid in water (Solvent A) : methanol (Solvent B) (40 : 60; v/v) in an isocratic elution followed by detection with positive ion electrospray ionization tandem mass spectrometry using the transitions of m/z 301 > 265 for CP and m/z 398 > 310 for OXP in multiple reaction monitoring mode. The calibration curve was linear in the range of 5.0–7000 and 10.0–6000 ng/ml for kidney and liver tissue homogenates, respectively. The method revealed good performances in terms of within‐batch, between‐batch precision (1.31–5.70%) and accuracy (97.0–102.24%) for CP in both kidney and liver tissue homogenates including lower and upper limits of quantification. The recoveries from spiked control samples were >81.0% and >87.0 % for CP and OXP, respectively. Matrix effect was found to be negligible, and the stability data were within the acceptable limits. Further, the validated LC/ES‐MS/MS method was successfully applied to investigate the distribution of CP in kidney and liver tissues after intravenous administration of CP to male Sprague Dawley rats. The results showed that the higher amount of CP was distributed in kidney followed by liver, which indicated that CP mainly accumulated in kidney tissues and renal excretion might be a primary and main elimination route. This is the first research approach focused on the quantitative determination and distribution of CP in rat kidney and liver tissue homogenates by using LC/ESI‐MS/MS, which could provide essential information for further pharmacological and clinical studies of CP. Copyright © 2015 John Wiley & Sons, Ltd.     

Pharmacokinetics and tissue distribution study of clevidipine and its primary metabolite H152/81 in rats

This present study was designed to investigate the pharmacokinetic profiles and tissue distribution characteristics of clevidipine and its primary metabolite H152/81 in rats following a single intravenous administration of clevidipine butyrate injectable emulsion. For this study, a sensitive and selective liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established and validated for the simultaneous quantitation of clevidipine and H152/81 in rat whole blood and various tissues. A Hedera ODS‐2 column with two gradient elution programs was employed for the troubleshooting of matrix effect on the detection of analytes among different biological samples. The experimental data showed that clevidipine represented quick elimination from blood with a half‐life of about 4.3 min and rapid distribution in all of the investigated tissues after administration; the highest concentration of clevidipine was found in the heart whereas the lowest concentration was detected in the liver. In addition, clevidipine was almost undetectable in most tissues except for heart and brain at 90 min post‐dosing, suggesting that there was no apparent long‐term accumulation in rat tissues. For H152/81, the peak concentration of 3714 ± 319 ng/mL occurred at 0.129 ± 0.048 h, the half‐life was 10.08 ± 1.45 h and area under the concentration–time curve was 42091 ± 3812 ng h/mL after drug administration. In addition, H152/81 was found at significant concentration levels in all tissues, in descending order of lung, kidney, heart, liver, spleen and brain at each time point. The results of current study offer useful clues for better understanding the distribution and metabolism of clevidipine butyrate injectable emulsion in vivo.     

高效液相色谱法测定大鼠组织中双酚A和4-壬基酚浓度

建立了大鼠组织中双酚A和4-壬基酚的提取和含量测定方法。大鼠组织样品经甲醇-乙酸铵缓冲液匀浆、 正己烷-乙醚混合溶剂提取、氮气吹干后用流动相溶解,以乙腈-0.01 mol/L乙酸铵缓冲液(pH 4.5)(体积比为75∶25)为流动相,经C18色谱柱分离,在激发波长227 nm、发射波长313 nm下进行荧光检测。大鼠心、脑、肝和肾脏组织样品中,双酚A的检出限为3.2~4.6 ng/g,4-壬基酚的检出限为11.8~15.6 ng/g;日内检测精密度为0.89%~4.50%,日间检测精密度为3.10%~12     

Determination of Olanzapine in rat brain using liquid chromatography with coulometric detection and a rapid solid-phase extraction procedure

A sensitive and selective method was developed for the determination of the antipsychotic drug Olanzapine levels in rat brain tissue, based on HPLC with electrochemical detection. The analyses were carried out on a C8 reversed phase column (150 mm x 4.6 mm, 5 microm), using a mobile phase composed of methanol and a phosphate buffer (44.0 mM, pH 3.5), containing triethylamine (21:79, v/v), flowing at 1.2 mL min(-1). A high sensitivity coulometric detection analytical cell containing two flow-through low volume working electrodes was used: electrode 1 was set at +0.350 V and electrode 2 at -0.200 V. Olanzapine, administered to rats in different doses or in different times, was extracted from tissue homogenate of either the whole brain or specific areas (cortex, hyppocampus, nucleus striatum) with a rapid solid phase extraction procedure (SPE) on Oasis HLB cartridges. The method provided a high extraction yield of Olanzapine and internal standard (2-methylolanzapine) from brain tissue homogenate with absolute recovery values higher than 90.0%. The detector response was linear over a concentration range of 0.2-100.0 ng mL(-1) of Olanzapine. The limit of quantification (LOQ) was 0.2 ng mL(-1). Precision results, expressed by the intra-day and the inter-day relative standard deviation values, were satisfactory, better than 4.6%. Accuracy was satisfactory as well. This method proved to be suitable for the analysis of Olanzapine in rat brain tissues and for the study of distribution and pharmacokinetics of Olanzapine in rat brain after a single treatment with the antipsychotic drug.     

LC-MS/MS method for the determination of cynandione A in rat plasma and tissues

A rapid and sensitive method using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) was developed and validated for the quantitative determination of cynandione A in rat plasma and tissues. The plasma samples were pretreated by liquid-liquid extraction with ethyl acetate after the internal standard (honokiol) had been spiked. The tissue samples were homogenized with physiological saline and treated further like the plasma samples. The separation was performed using a Zorbax SB-C(18) column (3.5 microm, 2.1 x 100 mm) and a C18 guard column (5 microm, 4.0 x 2.0 mm) with an isocratic mobile phase consisting of methanol-0.1% formic acid (78:22, v/v) at a flow rate of 0.2 mL/min. The Agilent G6410A triple quadrupole LC/MS system was operated under the multiple-reaction monitoring mode using the electrospray ionization technique in negative mode. The nominal retention times for cynandione A and honokiol were 1.41 and 2.63 min, respectively. The method was validated within the concentration range 0.2-1000 ng/mL in plasma and homogenized tissue for cynandione A, and the calibration curves were linear with correlation coefficients >0.992. The lower limit of quantification of cynandione A was 0.2 ng/mL. The intra-day and inter-day precision and accuracy of the assay in plasma were less than 14.4%, while the intra-day and inter-day precision and accuracy of the assay in tissue homogenate were less than 14.2%. This method proved to be suitable for study of pharmacokinetics and tissue distribution of cynandione A in rat.     

Determination of trimebutine maleate in rat plasma and tissues by using capillary zone electrophoresis.

A simple and rapid capillary zone electrophoresis method was developed for the determination of trimebutine maleate in rat plasma and tissues. Rat plasma and tissue homogenates were mixed with acetonitrile containing internal standard, ephedrine hydrochloride, and then centrifuged. The supernatant was dried under a stream of nitrogen, and the residue was reconstituted in methanol-water (1:1). The electrophoresis was performed in uncoated capillary with 30 mmol/L phosphate buffer of pH 6.0 as the separation electrolyte. The applied voltage was 10 kV and the UV detection was set at 214 nm. The peak height ratio vs concentration in plasma or homogenates was linear over the range of 5-500 ng/mL and the limit of quantitation was 5 ng/mL. The intra- and inter-day precision was RSD < 14% and <15%. The accuracy was relative error (RE) within +/- 14%. This method was applied to studying the pharmacokinetics and tissue distribution after a single dose of trimebutine maleate was administrated to the rats. The T(max), AUC, C(max) and t(1/2) were 30 min, 7.8 x 10(2) (ng/mL) min, 39 ng/mL and 1.7 x 10(2) min. The drug distribution was found in a decreasing order of liver, kidney, spleen, lung and heart.     

Pharmacokinetics and Tissue Distribution Study of Tryptanthrin in Rats by RP-HPLC with DAD Detector

A simple RP-LC-UV method was established for the determination of tryptanthrin in plasma and different tissues of rats. The separation was achieved by HPLC on a C₁₈ column with a mobile phases composed of acetonitrile?Cwater (47:53, v/v), UV detection was used at 251?nm. Good linearity was found between 0.0183?C1.1712???g?mL^?1 (r ²?=?0.999) for plasma and 0.0937?C1.7568???g?mL^?1 for the tissue samples, respectively (r ²????0.9932). The intra- and inter-day precisions expressed as the relative standard deviation for the method were 0.92?C6.01 and 1.06?C9.11?%, respectively. The relative recoveries of tryptanthrin ranged from 95.26 to 97.89?% for plasma and 82.55 to 114.99?% for tissue homogenates (except heart). The developed method was successfully applied to the pharmacokinetics and tissue distribution research after orally administration of a 56-mg?kg^?1 dose of tryptanthrin to healthy SD rats. The main pharmacokinetics distribution results showed that liver, lung, small intestine, and large intestine were the major distribution tissues of tryptanthrin in rats, and that tryptanthrin had difficulty in crossing the blood?Cbrain barrier.     

Distribution of suprofen in rats of both sexes

The tissue distribution of 3H-labeled DL-2-(4-(2-thienylcarbonyl) phenyl) propionic acid (suprofen) after po administration was studied in male, female, and pregnant rats by radiometry. The only tissues with concentrations comparable to plasma levels were those involved in metabolism and excretion (liver and kidney), except for the gastrointestinal tract, and all other tissue levels were very low. In pregnant rats, radioactivity crossed the blood-placenta barrier to a moderate extent and low concentrations were found in fetuses. Radioactivity disappeared from most tissues of male, female, and pregnant rats at rates similar to that from plasma and no appreciable radioactivity was found in rat tissues 24 h after dosing.     

Profiling histidine-containing dipeptides in rat tissues by liquid chromatography/electrospray ionization tandem mass spectrometry

The histidine-containing dipeptides carnosine (CAR) and structurally related anserine (ANS) and homocarnosine (HCAR), widely distributed in vertebrate organisms, have recently been proposed as endogenous quenchers for highly cytotoxic alpha,beta-unsaturated aldehydes generated by peroxidation. A sensitive, selective, specific and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric assay was developed and validated for the simultaneous determination of these peptides in biological matrices in order to establish their plasma/tissue distribution. Samples (plasma or tissue homogenates from male rats) were prepared by protein precipitation with HClO(4) (1 : 1, v/v) containing H-Tyr-His-OH as internal standard. The supernatant was separated on a Phenomenex Sinergy polar-RP column with a mobile phase of water-acetonitrile-heptafluorobutyric acid (9 : 1 : 0.01, v/v/v) at a flow-rate of 0.2 ml min(-1), with a run time of 10 min. Detection was effected on an ion trap mass spectrometer equipped with an electrospray ionization interface operating in positive ionization mode. The acquisitions were in the multiple reaction monitoring mode using the following precursor --> product ion combinations: H-Tyr-His-OH (internal standard) m/z 319 --> 301; CAR m/z 227 --> 210 + 209; ANS m/z 241 --> 224 + 197 + 170; HCAR m/z 241 --> 156. The method was validated over the concentration range 15-1000 nmol g(-1) and the limit of quantification (LOQ) and limit of detection (LOD) were 12.5 and 4.2 pmol injected, respectively. The intra- and inter-day precisions were <10% (< or =17.47% at the LOQ) and the intra- and inter-assay accuracies were within +/-10% for all concentrations. The mapping profile in rat tissue gave the following results: the highest concentrations of CAR and ANS were found in skeletal muscles (soleus, gastrocnemius, tibialis), followed by the heart, cerebellum and brain (ANS below the LOQ). HCAR was found only in the brain and cerebellum. No histidine-containing dipeptides were detectable in plasma, liver, kidney and lung.     

High-performance liquid chromatographic analysis of the anticancer drug oxantrazole in rat whole blood and tissues.

A reversed-phase high-performance liquid chromatographic (HPLC) assay was developed for the antitumor anthrapyrazole analogue, oxantrazole (OX), in rat whole blood and tissues. Blood samples were mixed with equal volumes of a 25% (w/v) aqueous solution of L-ascorbic acid, whereas tissue samples were homogenized with 1.5-3 volumes of an L-ascorbic acid-methanol-water (1:10:1, w/v/v) mixture to prevent oxidative degradation of OX. Samples were then treated with 60% (v/v) perchloric acid (25-30 microliters/ml of stabilized sample) to precipitate proteins, and centrifuged, with the resultant supernatants analyzed on HPLC utilizing a C8 column. The mobile phase for blood and urine samples consisted of 8% (v/v) glacial acetic acid, 13% (v/v) acetonitrile, 79% (v/v) water, 0.16% (w/v) sodium acetate, and 0.05% (w/v) L-ascorbic acid (final pH 2.7), and was pumped at 1.8 ml/min. Tissue samples were eluted at 2 ml/min with a mobile phase consisting of 8% (v/v) glacial acetic acid, 12% (v/v) acetonitrile, 80% (v/v) water, 0.16% (w/v) sodium acetate, and 0.0;5% (w/v) L-ascorbic acid. OX and internal standard were detected at 514 nm and had retention times of 2.3 and 3.1 min, respectively. The limit of quantitation of OX was 25-50 ng/g. Recovery of OX from biological samples ranged from 50 +/- 0.9% in spleen to 102.8 +/- 1.8% in RG-2 glioma. The analytical method was applied to a pharmacokinetic study in rats.     

LC Tissue Distribution Study of Paeonol in Rats after Oral Administration

Paeonol, an important constituent of the traditional Chinese medicine Cortex Moutan, has a variety of bioactivity. A simple and sensitive HPLC?CUV method has been developed for analysis of paeonol in different rat tissue (heart, liver, spleen, lung, kidney, and brain). Bio-samples were prepared by simple protein precipitation, and separation of paeonol was achieved on a C₁₈ column with methanol?C2% glacial acetic acid solution 70:30 (v/v) as mobile phase at a flow rate of 1.0 mL min^?1. UV detection was at 274 nm and the column temperature was 30 °C. Linearity was good between 0.025 and 5.0 ??g mL^?1 (r ² ?? 0.9990) for tissue samples. Inter-day and intra-day accuracy (as relative error, RE) and precision (as relative standard deviation, RSD) were <5.94 and 6.05%, respectively. The limit of detection was 0.025 ??g mL^?1 and extraction recovery for all samples was ??85.86%. The method was successfully applied to a tissue-distribution study after oral administration of 40 mg kg^?1 paeonol to healthy Sprague?CDawley rats. The study showed that paeonol was quickly distributed and eliminated after oral administration; liver and kidney were the major distribution tissues of paeonol in rats, and paeonol quickly passed through the blood?Cbrain barrier. It was also found there was no long-term accumulation of paeonol in rat tissues.     

Simultaneous determination of haloperidol and its metabolite, reduced haloperidol, in plasma, blood, urine and tissue homogenates by high-performance liquid chromatography.

A high-performance liquid chromatographic method was developed for the simultaneous determination of haloperidol and reduced haloperidol in human plasma, urine and rat tissue homogenates using bromperidol as an internal standard. The method involved extraction followed by injection of 50-80 microliters of the aqueous layer onto a C18 reversed-phase column. The mobile phase was 0.5 M phosphate buffer-acetonitrile-methanol (58:31:11, v/v/v) and the flow-rate was 0.6 ml/min. The column effluent was monitored by ultraviolet detection at 214 nm. The retention times for reduced haloperidol, haloperidol and bromperidol were 5.4, 7.2 and 8.4 min, respectively. The detection limits for haloperidol and reduced haloperidol in human plasma were both 0.5 ng/ml, and the corresponding values in human urine were both 5 ng/ml. The coefficients of variation of the assay were generally low (below 10.7%) for plasma, urine, blood and tissue homogenates. No interferences from endogenous substances or any drug tested were found.     

LC Determination of Icariside II in Rat Plasma and Tissues: Application to a Tissue Distribution Study

A sensitive and reliable reversed-phase liquid chromatography (RP-LC) with ultraviolet (UV) detection has been developed and validated for the quantification of Icariside II in rat plasma and tissues using Fermononetin as the internal standard. Protein precipitation and liquid?Cliquid extraction were utilized for plasma and tissue sample preparation, respectively. The analysis was successfully carried out on an Agilent SB-C₁₈ column (5 ??m, 4.6 × 250 mm) with the implementation of the following conditions: a mobile phase of phosphoric acid solution (0.1%, v/w)?CAcetonitrile (55:45, v/v), a flow rate of 1 mL min^?1, a column temperature of 25 °C and a detection wavelength of 270 nm. Good linear relationships of calibration curves were obtained (r ² > 0.9906) over the investigated concentration range with plasma and tissue samples. The lower limit of quantification (LLOQ) and the limit of detection (LOD) were 0.1 and 0.02 ??g g^?1, respectively (for plasma sample, they were 0.05 and 0.1 ??g mL^?1, respectively). The developed method which was embodied with good precision, accuracy, recovery and stability was corroborated to satisfy the requirements for biomedical sample analysis. This method has been successfully applied to tissue distribution study of Icariside II in rats after a single intravenous dose at 12.5 mg kg^?1. Results suggested that Icariside II was distributed to rat tissues rapidly with greater initial concentrations in kidney, lung and liver. Moderate initial distributions were obtained in rat muscle, heart, bone, spleen and plasma. Low amount of Icariside II was detected in testes, and no Icariside II could be detected in the brain.