• Archives of Pharmacal Research
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• 제29권4호
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• pp.339-342
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• 2006

A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the $C_{18}$ reverse-phased column. The mobile phase, $45\%$ methanol containing $1\%$ glacial acetic acid and $0.05\%$ 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The T max of tolperisone in Koreans $(0.94{\pm}0.42\;h)$ was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans $(1.14{\pm}0.27\;h)$ was shorter than that in Europeans $(2.56{\pm}0.2\;h)$. The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.200-205
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• 2021

Polynemoraline C, a pyridocoumarin alkaloid, exhibits anticholinergic, anti-inflammatory, antitumor, and antimicrobial activities. A sensitive analytical method of polynemoraline C in mouse plasma was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Polynemoraline C and ¹³C-caffeine (internal standard) in mouse plasma were extracted using a liquid-liquid extraction method coupled with ethyl acetate. This extraction method resulted in high and reproducible extraction recovery in the range of 73.49%-77.31% with no interfering peaks around the peak retention time of polynemoraline C and ¹³C-caffeine. The standard calibration curves for polynemoraline C were linear over the range of 0.5-200 ng/mL with r² > 0.985. The accuracy, precision, and the stability of the data were within acceptable limits on the FDA guideline. After intravenous and oral administration of polynemoraline C at doses of 5 and 30 mg/kg, respectively, the present method was successfully applied to the pharmacokinetic study of polynemoraline C. Polynemoraline C in mouse plasma showed a multi-exponential elimination pattern with a high volume of distribution values. This compound's absolute oral bioavailability was found to be 17.0%. Polynemoraline C's newly developed LC-MS/MS method can be used for further studies on the efficacy, toxicity, and biopharmaceutics of polynemoraline C, as well as its pharmacokinetic studies.

• Journal of Biomedical and Translational Research
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• 제19권4호
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• pp.130-139
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• 2018

This study aimed to analyze a high-performance liquid chromatography (HPLC) separation using a pentafluorophenyl column of parent drug hydroxychloroquine (HCQ) and its active metabolite, desethylhydroxchloroquine (DHCQ) applying to determine bioequivalence of two different formulations administered to patients. A rapid, simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for bioanalysis of HCQ and its metabolite DHCQ in human whole blood using deuterium derivative $hydroxychloroquine-D_4$ as an internal standard (IS). A triple-quadrupole mass spectrometer was operated using electrospray ionization in multiple reaction monitoring (MRM) mode. Sample preparation involves a two-step precipitation of protein techniques. The removed protein blood samples were chromatographed on a pentafluorophenyl (PFP) column ($50mm{\times}4.6mm$, $2.6{\mu}m$) with a mobile phase (ammonium formate solution containing dilute formic acid) in an isocratic mode at a flow rate of 0.45 mL/min. The standard curves were found to be linear in the range of 2 - 500 ng/mL for HCQ; 2 - 2,000 ng/mL for DHCQ in spite of lacking a highly sensitive MS spectrometry system. Results of intra- and inter-day precision and accuracy were within acceptable limits. A run time of 2.2 min for HCQ and 2.03 min for DHCQ in blood sample facilitated the analysis of more than 300 human whole blood samples per day. Taken together, we concluded that the assay developed herein represents a highly qualified technology for the quantification of HCQ in human whole blood for a parallel design bioequivalence study in a healthy male.

• 대한수의학회지
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• 제58권4호
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• pp.183-192
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• 2018

Although hyaluronic acid (HA) has been developed as a nanoparticle (NP; 320-400 nm) for a drug delivery system, the tissue targeting efficacy and the pharmacokinetics of HA-NPs are not yet fully understood. After a dose of 5 mg/kg of cyanine 5.5-labeled HA-NPs or HA-polymers was intravenously administrated into mice, the fluorescence was measured from 0.5 h to 28 days. The HA-NPs fluorescence was generally stronger than that of HA-polymers, which was maintained at a high level over 7 days in vivo, after which it gradually decreased. Upon ex vivo imaging, liver, spleen, kidney, lung, testis and sublingual gland fluorescences were much higher than that of other organs. The fluorescence of HA-NPs in the liver, spleen and kidney was highest at 30 min, where it was generally maintained until 4 h, while it drastically decreased at 1 day. However, the fluorescence in the liver and spleen increased sharply at 7 days relative to 3 days, then decreased drastically at 14 days. Conversely, the fluorescence of HA-polymers in the lymph node was higher than that of HA-NPs. The results presented herein may have important clinical implications regarding the safety of as self-assembled HA-NPs, which can be widely used in biomedical applications.

• Mass Spectrometry Letters
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• 제10권2호
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• pp.66-70
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• 2019

Rivaroxaban (RRN) is the first available active direct factor Xa inhibitor (anticoagulant) with oral administration. Due to its success in market, there have been efforts to develop various RRN formulations, and the development of good analytical methods for its in vivo evaluation is an essential prerequisite. Thus, here, a simple and efficient method to determine RRN in rat plasma using liquid-liquid extraction (LLE) and liquid chromatography and multiple reaction monitoring (LC-MRM) was presented. The use of ethyl acetate as the LLE solvent results appropriate extraction and purification of RRN and it also helps the significant reduction of rat plasma volume required for RRN quantitation. The developed method showed good analytical performance including specificity, linearity ($r^2{\geq}0.999$ within 0.5 - 500 ng/mL), sensitivity (the lower limit of quantitation at 0.5 ng/mL), accuracy (89.3 - 107.0%), precision (${\geq}12.7%$), and recovery (89.2 - 105.7%). Additionally, RRN in sample extracts showed good stability. Finally, the applicability of the validated method to the PK evaluation of RRN was confirmed after its oral administration to normal rats. The present method is the first analytical method employing LLE for the simple and efficient extraction and purification of RRN in rat plasma. Therefore, the present method can contribute to the development of new RRN formulations as well as to the monitoring of RRN in special clinical situations through its efficient determination in various samples with or without minor modification.

• 대한한의학회지
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• 제40권3호
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• pp.139-176
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• 2019

Objectives: This study aims to review the herbal medicines containing substances banned by World Anti-Doping Agency(WADA), and to consider criteria for the using of herbal medicines. Methods: Using foreign(Pubmed, Cochrane, Embase, Google Scholar, WANFANG, CiNii) and domestic databases (NDSL, OASIS, RISS), we analyzed the content and pharmacokinetics of the prohibited substances in herbal medicines. Results: Herbal medicines containing the prohibited substances proposed in Korea, China, and Japan are Ephedrae Herba, Cannabis Semen, Strychni Semen, Strychni Ignatii Semen, Pinelliae Tuber, Rhizoma Pinelliae, Chelidonii Herba, Papaveris Fructus Deseminatus, Liriopis Tuber, Rehmanniae Radix Recens, Cistanchis Herba, Ponciri Fructus Immaturus, Aurantii Fructus Immaturus, Moschus, Testudinis Plastrum, Otariae Testis et Penis, and Hominis Placenta. Of these, when using Ephedrae Herba, Cannabis Semen, Strychni Semen, Moschus, Strychni Ignatii Semen, and Otariae Testis et Penis, caution is needed in relation to the doping test. Other herbal medicines are considered safe for the doping test. In addition, by analyzing data related to higenamine added to the WADA's prohibited list of doping since 2017, we don't recommend using Nelumbinis Plumula. And in the case of the other herbal medicines containing higenamine, it is considered that care should be taken in doping test depending on the amount of usage. Conclusions: As a result of analyzing the herbal medicines which are in prohibited list about doping, we were able to know the criteria and precautions to use when prescribing the herbal medicines. Further research will be needed about common used herbal medicines and the amount of detection depending on extraction and boiling method.

• 한국임상수의학회지
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• 제36권3호
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• pp.159-165
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• 2019

Pimobendan is an inodilator used to treat canine heart failure, and pentoxifylline is reported to be beneficial for microcirculation and heart disease. The purpose of this study was to evaluate the pharmacokinetic and pharmacodynamic profiles of a novel pimobendan-pentoxifylline liquid mixture after oral administration to dogs. Eight healthy Beagle dogs were included in the study. The dogs were divided into the control group (orally administered water; n = 4) and experimental group (orally administered pimobendan-pentoxifylline liquid mixture [pimobendan 0.25 mg/kg, pentoxifylline 15 mg/kg]; n = 4). Plasma samples were obtained and echocardiographic indices were measured for 24 hours after administration. The concentrations of pimobendan and pentoxifylline were quantified by using a liquid chromatography-mass spectrometer (LC-MS). The elimination half-life ($T_{1/2}$) was $32.96{\pm}9.80mins$ for pimobendan and $29.49{\pm}6.67mins$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $52.50{\pm}31.22mins$ for pimobendan and $41.25{\pm}18.87mins$ for pentoxifylline. The maximum blood concentration ($C_{max}$) was $96.92{\pm}75.64ng/mL$ for pimobendan and $7074.07{\pm}3261.1ng/mL$ for pentoxifylline. Of the echocardiographic indices, fractional shortening (FS) and left ventricular internal diameter at end systole (LVIDs) were significantly altered at 1-3 hours after the administration of pimobendan-pentoxifylline liquid mixture. The pimobendan-pentoxifylline liquid mixture was well tolerated by the dogs, with no adverse effects observed during the study.

• 품질경영학회지
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• 제49권2호
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• pp.145-159
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• 2021

Purpose: A statistical similarity evaluation to compare pharmacokinetics(PK) profile data between nonclinical and clinical experiments has become a significant issue on many drug development processes. This study proposes a new similarity index by considering important parameters, such as the area under the curve(AUC) and the time-series profile of various PK data. Methods: In this study, a new profile similarity index(PSI) by using the concept of a process capability index(Cp) is proposed in order to investigate the most similar animal PK profile compared to the target(i.e., Human PK profile). The proposed PSI can be calculated geometric and arithmetic means of all short term similarity indices at all time points on time-series both animal and human PK data. Designed simulation approaches are demonstrated for a verification purpose. Results: Two different simulation studies are conducted by considering three variances(i.e., small, medium, and large variances) as well as three different characteristic types(smaller the better, larger the better, nominal the best). By using the proposed PSI, the most similar animal PK profile compare to the target human PK profile can be obtained in the simulation studies. In addition, a case study represents differentiated results compare to existing simple statistical analysis methods(i.e., root mean squared error and quality loss). Conclusion: The proposed PSI can effectively estimate the level of similarity between animal, human PK profiles. By using these PSI results, we can reduce the number of animal experiments because we only focus on the significant animal representing a high PSI value.

• 한국임상약학회지
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• 제31권2호
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• pp.125-135
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• 2021

Background: Generally, pharmacokinetics (PK) models could be stratified into two models. The compartment PK model uses the concept of simple compartmentalization to describe complex bodies, and the physiologically based pharmacokinetic (PBPK) model describes the body using multi-compartment networking. Notwithstanding sharing a theoretical background in both models, there was still a lack of knowledge to enhance compatibility in both models. Objective: This study aimed to evaluate the compatibility among PBPK, lumping model and compartment PK model with voriconazole PK case study. Methods: The number of compartments and blood flow on each tissue in the PBPK model were modified using the lumping method, considering physiological similarities. The concentration-time profiles and area under the concentration-time curve (AUC) parameters were simulated at each model, assuming taken voriconazole oral 400 mg single dose. After that, those mentioned PK parameters were compared. Results: The PK profiles and parameters of voriconazole in the three models were similar that proves their compatibility. The AUC of central compartment in the PBPK and lumping model was within a 2-fold range compared to those in the 2- compartment model. The AUC of non-eliminating tissues compartment in the PBPK model was similar to those in the lumping model. Conclusion: Regarding the compatibility of the three PK models, the utilization of the lumping method was confirmed by suggesting its reliable PK parameters with PBPK and compartment PK models. Further case studies are recommended to confirm our findings.

• BMB Reports
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• 제55권4호
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• pp.175-180
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• 2022

Peptides are gaining substantial attention as therapeutics for human diseases. However, they have limitations such as low bioavailability and poor pharmacokinetics. Periostin, a matricellular protein, can stimulate the repair of ischemic tissues by promoting angiogenesis. We have previously reported that a novel angiogenic peptide (amino acids 142-151) is responsible for the pro-angiogenic activity of periostin. To improve the in vivo delivery efficiency of periostin peptide (PP), we used proteins self-assembled into a hollow cage-like structure as a drug delivery nanoplatform in the present study. The periostin peptide was genetically inserted into lumazine synthase (isolated from Aquifex aeolicus) consisting of 60 identical subunits with an icosahedral capsid architecture. The periostin peptide-bearing lumazine synthase protein cage nanoparticle with 60 periostin peptides multivalently displayed was expressed in Escherichia coli and purified to homogeneity. Next, we examined angiogenic activities of this periostin peptide-bearing lumazine synthase protein cage nanoparticle. AaLS-periostin peptide (AaLS-PP), but not AaLS, promoted migration, proliferation, and tube formation of human endothelial colony-forming cells in vitro. Intramuscular injection of PP and AaLS-PP increased blood perfusion and attenuated severe limb loss in the ischemic hindlimb. However, AaLS did not increase blood perfusion or alleviate tissue necrosis. Moreover, in vivo administration of AaLS-PP, but not AaLS, stimulated angiogenesis in the ischemic hindlimb. These results suggest that AaLS is a highly useful nanoplatform for delivering pro-angiogenic peptides such as PP.