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Currently, safety pharmacological tests for the central nervous system depend on animal behavioral analysis. However, due to the subjectivity of behavioral analysis and differences between species, there is a limit to appropriate nervous system toxicity assessment, therefore a new neurotoxicity assessment that can simulate the human central nervous system is required.In our study, we developed an in vitro neurotoxicity assessment focusing on neuronal function. To minimize the differences between species and fast screening, hiPSC-derived neurons and a microelectrode array (MEA) that could simultaneously measure the action potentials of the neuronal networks were used. After analyzing the molecular and electrophysiological characters of our neuronal network, we conducted a neurotoxicity assessment on neurotransmitters, neurotoxicants, illicit drugs, and new psychoactive substances (NPS). We found that most substances used in our experiments responded more sensitively to our MEA-based neurotoxicity assessment than to the conventional neurotoxicity assessment. Also, this is the first paper that evaluates various illicit drugs and NPS using MEA-based neurotoxicity assessment using hiPSC-derived neurons.Our study expanded the scope of application of neurotoxicity assessment using hiPSC-derived neurons to NPS, and accumulated evaluation data of various toxic substances for hiPSC-derived neurons.

Two new psychoactive substances (NPSs) classified as phenethylamines, namely 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH), are being abused by people seeking recreational hallucinogens. These NPSs may cause serious health problems as their adverse effects are not known in most cases. Therefore, in the present study, we evaluated the cardiotoxicity of 25I-NBOH and 25C-NBOH using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), Langendorff test, and human ether-a-go-go-related gene (hERG) assay. Furthermore, we analyzed the expression levels of p21 CDC42/RAC1-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, treatment with 25I-NBOH or 25C-NBOH dramatically decreased viability of H9c2 cardiomyocytes. Meanwhile, these two compounds significantly increased QT intervals and RR intervals in the rat ECG measurement. 25I-NBOH down-regulated the PAK1 protein expression in rat primary cardiomyocytes as well as H9c2 cells. However, 25C-NBOH had no effect on the PAK1 expression in H9c2 cells. In an in-depth study, 25I-NBOH inhibited potassium channels in the hERG assay, but in ex vivo test, the substance did not affect the left ventricular developed pressure (LVDP) and heart rate of the isolated rat hearts. Taken together, these results suggest that both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effect. Further investigation would be needed to determine which factors mainly influence the relationship between PAK1 expression and cardiotoxicity.

Prolintane (1-Phenyl-2-pyrrolidinylpentane), a synthetic central nervous system (CNS) stimulant, is structurally similar to amphetamine but pharmacologically acts as a dopamine reuptake inhibitor like cocaine. While several case studies reported adverse effects and recreational use of prolintane, the abuse potential of the drug has not been systemically examined yet. In the present study, we evaluated the behavioral effects of prolintane regarding its abuse liability in rodents using locomotor activity, conditioned place preference (CPP), self-administration (SA), and drug discrimination paradigms, as well as in-vivo microdialysis experiment. First, acute prolintane (10 and 20 mg/kg, intraperitoneal injection) increased locomotor activity (distance traveled, cm) in mice but to a lesser degree than methamphetamine (as a positive control). We also found that a single and solitary injection of prolintane (20 mg/kg, IP) significantly increased extracellular dopamine in the striatum. The following result suggests that its stimulatory effects might be associated with the mesolimbic dopaminergic pathway. Further, prolintane produced a significant drug-paired place preference at doses of both 10 and 20 mg/kg. In the SA experiment, the mice that self-administered prolintane intravenously (4 mg/kg/inf) showed a higher infusion and active lever responses but not inactive lever responses. Additionally, cumulative doses of prolintane partially elicited cocaine-appropriate lever responses (38.57% at doses up to 10 mg/kg) in rats. These results implied that prolintane has not only rewarding and reinforcing effects but also interoceptive stimulus properties, which are similar to cocaine at a moderate level. Taken together, this study was the first to show, to our knowledge, that prolintane has a certain level of abuse potential and should be considered carefully as a valuable basis for legal restrictions on use.

A recent in vitro cardiovascular safety pharmacology test uses cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) to overcome the limitations of the classical test systems, such as species differences and local channel analysis. The Comprehensive in vitro Proarrhythmia Assay (CiPA) is a new proarrhythmia screening paradigm proposed by a CiPA steering expert group, which essentially requires iPSCs derived cardiomyocyte-based electrophysiological evaluation technology. Moreover, the measurement of the contractile force is also emerging as an important parameter to recapitulate non-proarrhythmic cardiotoxicity. Therefore, we constructed an multielectrode assay (MEA) evaluation method that can measure the electrophysiological changes with 6 reference drugs in hiPSC-derived cardiomyocytes. Subsequently, it was confirmed that the electrophysiological were changed in accordance with the mechanism of action of the drugs. Furthermore, based on the multi-probe impedance, we confirmed the decrease in contractile force due to treatment with drugs, and developed a platform to evaluate cardiotoxicity according to drugs along with field potential changes. Our excitation–contraction coupling cardiotoxicity assessment is considered to be more supportive in cardiac safety studies on pharmacologic sensitivity by complementing each assessment parameter.

Dissociative-based new psychoactive substances (NPSs) are increasingly available through the Internet, and public health problems related to the recreational use of these substances have been increasing globally. Two such NPSs are deschloroketamine and diphenidine, which are primarily used recreationally as ketamine substitutes. However, there is little scientific evidence to describe the dependence liability of NPSs. This study aimed to evaluate the dependence liability of deschloroketamine and diphenidine via animal behavioral experiments. We evaluated the rewarding and reinforcing effects of these NPSs using the conditioned place preference (CPP) and the self-administration (SA) paradigms in mice. Psychomotor effects and behavioral features of these compounds were assessed by quantifying locomotor activity, stereotypic movements, and dopaminergic neurotransmission. Both deschloroketamine (10 mg/kg) and diphenidine (10-60 mg/kg) produced increased locomotor activation and stereotypy that were similar to the effects of ketamine (10 mg/kg). Both deschloroketamine (10 mg/kg) and diphenidine (10, 20 mg/kg) increased the animals' preference for the drug-paired compartment in the CPP testing. In the SA testing, deschloroketamine (1 mg/kg/infusion) increased the number of active lever presses and the number of infusions received, whereas diphenidine administration (1, 2 mg/kg/infusion) did not alter either of these. Furthermore, both deschloroketamine and diphenidine increased dopamine levels in PC-12 cells. Collectively, the data suggest that deschloroketamine may have both rewarding and reinforcing effects, whereas diphenidine only induced rewarding effect.

N-Methyl-1-(naphthalen-2-yl)propan-2-amine (methamnetamine, PAL-1046) is an amphetamine-based new psychoactive substance (NPS). Methamnetamine has been reported to cause excessive release of serotonin, and it is classified as an empathogen or entactogen. It is not regulated as a controlled substance in most countries, and there are no studies on its metabolism. In this study, in vitro phase I metabolism of methamnetamine in human liver microsomes (HLM) and flavin-containing monooxygenase (FMO) was investigated by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS). Eight metabolites of methamnetamine were identified and were structurally characterized achieved by a combination of accurate mass analysis and tandem mass spectrometry. The identified metabolic processes include N-demethylation, N-hydroxylation, aromatic hydroxylation, and a combination of these processes. N-Hydroxylated metabolites were confirmed based on expressed FMOs. The major metabolite was formed from methamnetamine via hydroxylation of the naphthalene ring after the in vitro phase I process. These results could help detect methamnetamine ingestion by NPS abusers.

에너지 음료는 카페인을 주성분으로 타우린, 비타민 같은 다른 energy-enhancing 성분을 함유하고 있다. 미국과 유럽에서는 글루쿠로노락톤이 에너지 음료에 첨가될수 있으나, 국내에서 의약품으로는 허가되어 있다. 따라서 식품첨가물로는 그 사용이 금지 되어 있어, 지속적으로 수입 및 유통 음료에서 시험검사를 하여 규제하고 있다. 현재 분석법으로 사용하는 LC-PDA 법은 복잡한 유도체화 과정을 거치고, 음료 중에 당류들이 위양성 결과를 나타내기도 한다. 이런 기존 방법의 단점을 개선하기 위해 HILICESI-MS/MS (hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry)를 이용한 분석법을 개발하고, 선택성, 직선성, 검출한계, 정량한계, 정밀도, 정확성, 재현성에 대하여 분석법 유효성 검증을 수행했고, AOAC, EURACHEM 가이드라인에 부합되는 결과를 얻었다.

Genetically modified (GM) papaya line 55-1, which is resistant to PRSV infection, has been marketed globally. Prompt and sensitive protocols for specific detections are essential for the traceability of this line. Here, an event- and construct-specific real-time polymerase chain reaction (RT-PCR) method was established to detect 55-1. Qualitative detection was possible for fresh papaya fruit up to dilutions of 0.005% and 0.01% for the homozygous SunUp and heterozygous Rainbow cultivars, respectively, in non-GM papaya. The method was applied in the qualitative detection of 55-1 in eight types of commercially processed papaya products. Additionally, papaya products were monitored to distinguish GM papaya using the P35S and T-nos RT-PCR detection methods. As expected, detection capacity was improved via modified sample preparation and the established RT-PCR detection method. Taking these results together, it can be suggested that a suitable method for the extraction and purification of DNA from processed papaya products was established for the detection of GM papaya.

According to Centers for Disease Control and Prevention (CDC, USA) recently it was reported that the children (< 5 year-old children) were more susceptible to Foodborne-illness 1) . Confectionery products should be strictly controlled because they are children-preferred foods. Ministry of Food and Drug Safety (MFDS, South of Korea) tried to monitor contamination of organisms in confectionery products (such as biscuits, candies, chewing gums and ice candies) distributed in South Korea. MFDS evaluated the levels of indicator organisms: total aerobic bac- teria, coliforms, Escherichia coli as well as the levels of food-borne illness organisms: Staphylococcus aureus, Bacillus cereus, Clostridium perfringens. Experimental plans for microbiological test were in accordance with the Interna- tional Commission on Microbiological Specifications for Food (ICMSF). For this study, 1,005 samples were collected and from Seoul and Gyeongin region, South Korea. The average level of total aerobic bacteria in 1,005 samples was 1.7 log Colony Forming Unit(CFU)/g and the detection rate was 26.8%. The average level of Bacillus cereus was detected in 1.7 log CFU/g and the rate was 0.9%. There was no detection of coliforms, Escherichia coli, Staphylococ- cus aureus and Clostridium perfringens. The results of this study will be provided as the basic data to set the reason- able microbiological criteria of Korea Food Code.

The paper deals with the selection of 3D display devices in accordance with the user`s conveniences and accuracy of spatial information by applying 3D display devices to Spatial Information Update System (SIUS) which generate edit and update digital thematic maps. After applying different manufacturer`s 3D display devices to SIUS, aerial images acquired from the stereo images were displayed through the devices and spatial information was extracted from the displayed 3D images. Assessment of 3D display devices were based on quantitative and qualitative analysis on accuracy of spatial information and user`s conveniences. Planar`s PL2020 and Redrover`s Tru3Di 3D monitor has expressed outstanding display environment in 3D related tasks for the generation of spatial information compared to other 3D display devices. System improvement is expected regarding accuracy of spatial information, work efficiency and user`s conveniences.

For the quantification of azasetron in rat plasma samples, a column-switching HPLC method was developed and validated. Following dilution of plasma samples with mobile phase A (17 mM potassium phosphate buffer (pH 3.0)) and simple protein precipitation by addition of perchloric acid (60%), the mixture was directly injected onto the pre-column. After endogenous plasma substances were eluted to waste, the analyte was transferred to the trap column by switching the system. Then, the analyte was back-flushed to the analytical column for separation with mobile phase B (a 22:78 v/v mixture of acetonitrile and 17 mM potassium phosphate buffer (pH 3.0)) and detected at 250 nm using a photodiode array detector. A linear standard curve was obtained in the concentration range of 10-800 ng/mL with the correlation coefficient (r) of 0.9998. The intra- and inter-day precision and accuracy values for azasetron were in the ranges of 0.3-12.9% and 89.7-101.4%, respectively. The method was valid in terms of specificity, precision, and accuracy. In addition, this efficient analytical method was successfully applied to determine plasma concentrations of azasetron following oral administration of azasetron at a dose of 4.0 mg/kg to rats.

Toxicogenomics has the potential to be used for the regulatory decision making to predict toxicity in developing new drugs. We have identified the classifiers for hepatotoxicity prediction in nonsteroidal anti inflammatory drugs (NSAIDs) through analyzing differential gene expression profiles of hepatotoxic and nonhepatotoxic compounds using HepG2 cell. 100 μM of 8 hepatotoxic and 8 nonhepatotoxic NSAIDs were treated to HepG2 cell and the analysis of gene expression changes after 24 h allowed a set of genes to be identified differentiating hepatotoxicants from nonhepatotoxicants by statistical method. The hepatotoxicity prediction model was built using the selected 77 genes. These genes and pathways, commonly regulated by hepatotoxicants, may be indicative of the early characterization of hepatotoxicity and possibly predictive of later hepatotoxicity onset. 4 test compounds including hepatotoxic and nonhepatotoxic NSAIDs were used for validating the prediction model and the accuracy was 100%. Given that the specificity and sensitivity showed 100%, these are the most precise classifiers identified until now.

An accurate, sensitive and simple reverse-phase (RP) high-performance liquid chromatography (HPLC) assay has been developed and validated for the simultaneous quantitative determination of tipranavir with nine other antiretroviral drugs in plasma. A liquid–liquid extraction of the drugs in tert -butylmethylether (TBME) from 200 μL of plasma is followed by a reversed phase gradient HPLC assay with UV detection at 210 nm. The standard curve for the drug was linear in the range of 80–80,000 ng/mL for tipranavir; 10–10,000 ng/mL for nevirapine, indinavir, efavirenz, and saquinavir; and 25–10,000 ng/mL for amprenavir, atazanavir, ritonavir, lopinavir, and nelfinavir. The regression coefficient ( r 2 ) was greater than 0.998 for all analytes. This method has been fully validated and shown to be specific, accurate and precise. Due to an excellent extraction procedure giving good recovery and a clean baseline, this method is simple, rapid, accurate and provides excellent resolution and peak shape for all analytes. Thus this method is very suitable for therapeutic drug monitoring.

A column-switching high-performance liquid chromatographic (HPLC) method has been developed and validated for quantification of fluvastatin in rat plasma. Plasma samples were diluted with an equal volume of mobile phase, i.e. acetonitrile–5 mM potassium phosphate buffer (pH 6.8) (15:85, v/v), and the mixture was directly injected onto the HPLC system. The analyte was enriched in a pre-treatment column, while endogenous components were eluted to waste. The analyte was then back-flushed onto an analytical column and quantified with fluorescence detection (λex = 305 nm; λem = 390 nm). The standard curve for the drug was linear in the range 0.5–100 ng mL−1 in rat plasma. The limit of quantitation for plasma was found to be 0.5 ng mL−1. This method has been fully validated and shown to be specific, accurate and precise. The method is simple and rapid because of a minimized sample preparation and appears to be useful for the pharmacokinetic study of fluvastatin.

To examine the effects of food on plasma concentration and bioavailability of fenofibrate administered as a sustained-release capsule.Twenty-four healthy Korean volunteers were enrolled in a randomised, open-label, balanced, three-treatment, three-period, three-sequence, single oral dose, crossover pharmacokinetic study. A single dose of fenofibrate (250 mg sustained-release capsule) was administered on three occasions -- after overnight fasting, after consumption of a standard breakfast and after a high-fat breakfast. Serial blood samples were collected for the next 72 hours. Plasma fenofibric acid concentrations were measured by high-performance liquid chromatography, and pharmacokinetic parameters were calculated.The pharmacokinetic parameters were significantly affected by food intake. The high-fat breakfast affected the rate of absorption of fenofibrate more than the standard breakfast and fasted conditions. Specifically, the area under the plasma concentration-time curve from time zero to infinity (AUC(infinity)) and peak plasma concentration (C(max)) increased 2.45-fold and 2.89-fold, respectively, between the fasted and standard-fed conditions (p0.01). In addition, the high-fat meal caused 3.34-fold and 3.82-fold increases compared with the fasted condition in AUC(infinity) and C(max), respectively. A one-compartment open model with lag time successfully described the plasma concentrations of fenofibric acid.In healthy volunteers, AUC(infinity) and C(max) of fenofibrate, when administered via sustained-release capsules immediately after the consumption of food, was increased significantly from the fasting conditions (p0.01). The greatest AUC(infinity) and C(max) occurred when the capsules were taken after a high-fat breakfast.

In Korea, generic drug and bioequivalence test are the hot issues since a new medical system of separation of dispensary from medical practice was started in 2000. The KFDA(Korea FDA) had revised several times . In vitro dissolution test has been extensively used as a quality control tool for solid oral dosage forms. In an effort to minimize unnecessary human testing, in vitro/in vivo correlations (IVIVC) between in vitro dissolution and in vivo bioavailability are increasingly becoming an integral part on extended release drug product development. The recently published US guidance, will be helpful for us to make our own guideline.

Numerous drugs are chiral because they possess one or more chiral centers. Enantiomers may differ in their pharmacokinetic, pharmacological and toxicological properties. However, the significance of stereochemistry of drugs in their therapeutic uses has received relatively little attention until recently. The US FDA issued a guideline on stereoisomeric drugs in 1992, and the European agency describes tests for new drug substances which are optically active in an ICH(International Conference of Harmonization) guideline. According to the guidance, enantiomers may differ in their pharmacokinetic, pharmacological and toxicological properties. Therefore, in this paper, we examined the recently published Canadian guidance, stereochemical issues in chiral drug development, which will be references to make a guidance on stereochemical issues in chiral drug development in Korea.

After new medical system of separation of dispensary from medical practice was started in 2000 in Korea, to expand bioequivalence-proven drug products and to ensure the credibility of the therapeutic equivalence of generic drugs are hot issues in Korea. It will be obligatory to submit bioequivalence reports for getting licenses of all generic prescription drugs in the near future. Like other countries such as US and Japan, the KFDA also has a plan to re-evaluate the already approved drugs by bioequivalence studies. Therefore, it becomes more necessary to develop bioequivalence-demonstrating methods for specific preparations such as topical drug products among already approved drug products. There are some differences between US and Japanese guidances of bioequivalence studies of generic drug products for topical use. The information on Japanese guidance and the guidance's Q&As is already provided in our previous paper. In this paper, we examined the US guideline published in 1995 and compared with the Japanese guideline, which will give a useful information to make a guidance on bioequivalence studies of topical drug products in Korea.

A new medical system of separation of dispensary from medical practice was started in 2000 in Korea. To expand bioequivalence-proven drug products and to ensure the credibility of the therapeutic equivalence of generic drug are hot issues in Korea. The KFDA also has a plan to revise the pharmaceutical affairs law that bioequivalence reports of all the generic prescription drugs should be submitted to the KFDA in the application for drug approval. Therefore, it becomes more necessary to develop bioequivalence-demonstrating methods for specific preparations such as topical drug products. There are some differences between US and Japanese guidances of bioequivalence studies of generic drug products for topical use. In this paper, we examined the recently published Japanese guideline, Guideline for Bioequivalence Studies of Generic Products For Topical Uses, and Q&A of the guideline, which will be references to make a guidance on bioequivalence studies of topical drug products in Korea.

A new medical system was started in Korea in 2000 and pharmaceutical affairs law was revised in 2001. According to the revised law, generic substitution is permitted only to the drug products which are proven to be bioequivalent to the reference listed drugs. To expand the list of bioequivalence-proven drug products and to ensure the credibility of the therapeutic equivalence of generic drug are the hot issues in Korea. Also, the KFDA has a plan to revise the pharmaceutical affairs law that bioequivalence reports of all the generic prescription drug products should be submitted to the KFDA for drug approval after July in 2004. Therefore, it is increasing the necessity to develop the bioequivalence-demonstrating methods for specific drug substances and preparations which require to conduct food-effect bioavailability or bioequivalence study. There are some differences between US and Japanese guidances of food-effect bioavailability and bioequivalence studies. In this paper, we examined the recently published US guidance about food-effect study and it will be a reference to make our own guidance about food-effect bioavailability and bioequivalence guidances in Korea.

A sensitive and selective liquid chromatographic method coupled with mass spectrometry (LC-MS) was developed for the quantification of phloroglucinol in human plasma. Resorcinol was used as internal standard, with plasma samples extracted using ethyl acetate. A centrifuged upper layer was then evaporated and reconstituted with mobile phase. The reconstituted samples were injected into a C(18) XTerra MS column (2.1 x 100 mm) with 3.5-microm particle size. The analytical column lasted for at least 500 injections. The mobile phase was 15% acetonitrile (pH 3.0), with flow-rate at 200 microl/min. The mass spectrometer was operated in negative ion mode with selective ion monitoring (SIM). Phloroglucinol was detected without severe interferences from plasma matrix when used negative ion mode. Phloroglucinol produced a parent molecule ([M-H](-)) at m/z 125 in negative ion mode. Detection of phloroglucinol in human plasma was accurate and precise, with quantification limit at 5 ng/ml. This method has been successfully applied to a study of phloroglucinol in human specimens.

In order to study the simultaneous determination of (+)- and (-)-cetirizine in human urine we have developed a chiral separation method by HPLC. A chiral stationary phase of alpha1-acidglycoprotein, the AGP-CSP, was used to separate the enantiomers. The pH of the phosphate buffer, as well as the content of the organic modifier in the mobile phase, markedly affected the chromatographic separation of (+)- and (-)-cetirizine. A mobile phase of 10 mmol/l phosphate buffer (pH 7.0)-acetonitrile (95: 5, v/v) was used for the urine assays. Ultraviolet absorption was monitored at 230 nm and roxatidine was employed as the internal standard for quantification. (+)-Cetirizine, (-)-cetirizine and the internal standard were eluted at retention times of 12, 16, and 32 mins, respectively. The detection limit for cetirizine enantiomers was 400 ng/ml of urine. A pharmacokinetic study was conducted with the help of 5 healthy female volunteers who were administered with a single oral dose of racemic cetirizine (20 mg). The peak area ratios provided by the cetirizine enantiomers were linear (r0.997) over a concentration range of 2.5-200 microg/ml. The peak of the excreted cetirizine enantiomers appeared in the urine sample during the period of 1-2 hrs following the administration of the oral dose. The excreted level of (+)-cetirizine was slightly higher than (-)-cetirizine but the difference was not statistically significant. However, this method appears to have applications for enantioselective pharmacokinetic studies of racemic drugs.

The biotransformation of xylazine, a widly used animal tranquilizer, was investigated in rats. After administration of xylazine, the existence of 2,6-dimethylphenylisothiocyanate, 2,6-dimenthyl-4-hydroxy-aniline andp-hydroxy-xylazine in urine was confirmed by the comparison with chemically prepared standards in GC/MS. The main metabolite,p-hydroxy xylazine was excreted as conjugated form.

This study is to research the quantitative structure-permeability relationship of 20 drugs having similar structure. Permeability was determined by using the Caco-2 cell in vitro model. The apparent permeability coefficient (Papp) of each drug both of apical to basolateral side and basolateral to apical side was measured at the concentration corresponding to 0.1 times the highest dose strength of 250 mL dissolved buffer. In order to test the permeability system suitability, we measured the Papp of 19 model drugs out of 20 which presented in 'Waiver of In Vivo Bioavailability and Bioequivalence Studies for Immediate-Release Solid Oral Dosage Forms based on the Biopharmaceutics Classification System' of FDA guidance. Also, we demonstrated the functional expression of efflux systems (e.g., p-gp) by bi-directional transport studies with rhodamine 123. Also, as a result of the study on quantitative structure-permeability relationship by using the partial least square method, it was possible to predict the permeability of drugs from their 3D structure. The quantitative structure-permeability relationship provided a cross-validated q2=0.789, a normal r2=0.998. Considering all of above results, analysis on this quantitative structure-permeability relationship appears to be a very useful tool to predict the permeability.

Enantiomers may confer benefits over racemates in therapeutic uses and we developed a chiral separation method of cetirizine enantiomers, a second generation H1 histamine receptor antagonist, in rat plasma. alpha1-Acidglycoprotein based chiral stationary phase(AGP-CSP), monitored with UV at 230 nm was used to separate the enantiomers. Observed enantioselectivity (alpha) was 2.0. The AGP-CSP was also used at a preparative scale to isolate the enantiomers with an optical purity of greater than ee 99%. In addition, an analysis was carried out for the cetirizine enantiomers in rat plasma to study the differences of enantiomers in pharmacokinetics. Both (+)- and (-)-cetirizine were separated using a reversed-phase column of AGP, and were detected at the range of 2.5-200 microg ml(-1) in plasma. Although there was no recognizable differences in pharmacokinetics between the enantiomers in rat, the method appears to be useful for their pharmacokinetic studies.