Research article Received: 27 December 2013,

Revised: 23 January 2014,

Accepted: 17 February 2014

Published online in Wiley Online Library: 7 April 2014

(wileyonlinelibrary.com) DOI 10.1002/bmc.3185

A sensitive and selective method for the quantitative analysis of miglitol in rat plasma using unique solid-phase extraction coupled with liquid chromatography–tandem mass spectrometry Akiko Mizuno-Yasuhira*, Kohnosuke Kinoshita, Shigeji Jingu and Jun-ichi Yamaguchi ABSTRACT: A sensitive, selective and robust liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of miglitol in rat plasma. The sample preparation procedures involved protein precipitation and unique solid-phase extraction, which efficiently removed sources of ion suppression and column degradation interference present in the plasma. Chromatographic separation was achieved on an amide column using 10 mmol/L CH3COONH4 and CH3CN:CH3OH (90:10, v/v) as the mobile phase under gradient conditions. Detection was performed using tandem mass spectrometry equipped with an electrospray ionization interface in positive ion mode.The selected reaction monitoring transitions for miglitol and a stable isotope-labeled internal standard were m/z 208 → m/z 146 and m/z 212 → m/z 176, respectively. The correlation coefficients of the calibration curves ranged from 0.9984 to 0.9993 over a concentration range of 0.5–100 ng/mL plasma. The quantification limit of the proposed method was more than 10 times lower than those of previously reported LC-MS/MS methods. The novel method was successfully validated and applied to a pharmacokinetic study in rats. Copyright © 2014 John Wiley & Sons, Ltd. Keywords: miglitol; monomeric sugar; LC-MS/MS; plasma; quantification; SPE

Introduction

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* Correspondence to: Akiko Mizuno-Yasuhira, Pharmacokinetics and Metabolism, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co. Ltd, Japan. Email: [email protected] Pharmacokinetics and Metabolism, Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co. Ltd, 1-403, Yoshino-cho, Kita-ku, Saitama-shi, Saitama, 331-9530, Japan Abbreviations used: α-GI, α-glucosidase inhibitor; PD, pharmacodynamic; PK, pharmacokinetic; PPT, protein precipitation; SPE, solid-phase extraction; SRM, selected reaction monitoring; TIS, TurboIonSpray®.

Copyright © 2014 John Wiley & Sons, Ltd.

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The α-glucosidase inhibitor (α-GI) miglitol [(2R,3R,4R,5S)-1-(2hydroxyethyl)-2-(hydroxymethyl) piperidine-3,4,5-triol] is a pseudomonomeric sugar that inhibits glucose absorption from the intestine (Bishoff, 1994; Ahr et al., 1997). Miglitol is useful for the treatment of type 2 diabetes mellitus because it significantly reduces the increase in the plasma glucose level that occurs after a meal (Tsujino et al., 2011) when administered either as a monotherapy (Segal et al., 1997; Johnston et al., 1998a, 1998b; Narita et al., 2012) or in combination with either an oral antidiabetic agent (Gaal et al., 2001) or insulin (Mitrakou et al., 1998). A recent investigation demonstrated that the administration of miglitol was effective for preventing reactive hypoglycemia secondary to late dumping syndrome, and the efficacy of this agent was superior to that of two other α-GIs, voglibose and acarbose (Fujita et al., 2012). However, the mechanism responsible for the advantage of miglitol remains unknown. Knowledge of this mechanism might suggest a more effective cure for reactive hypoglycemia secondary to late dumping syndrome; hence, precise pharmacodynamic studies in both preclinical and clinical research settings are needed to elucidate this mechanism. As part of a pharmacodynamics study, a pharmacokinetic/pharmacodynamic (PK/PD) analysis of miglitol in rats, which are useful experimental animals for pharmacological

investigations, would be valuable. Therefore, a convenient method for quantifying miglitol in rat plasma is required. A method for quantifying miglitol in rat plasma has been reported (Ahr et al., 1997). However, the authors investigated the rat PK profiles based on plasma concentrations that were determined using radioactive isotope detection. This method is rather inconvenient, as specialized radioisotope facilities are required and the handling of isotopes is potentially hazardous. Furthermore, analysis methods using 3H- or 14C-miglitol lack selectivity, since they do not involve chromatographic separation. While more highly selective liquid chromatography–tandem mass spectrometry (LC-MS/MS) methods for quantifying miglitol in human plasma that do not require the inconvenient handling of

A. Mizuno-Yasuhira et al. isotopes have been reported (Li et al., 2007; Nirogi et al., 2006), the analytical performance of these methods has been unsatisfactory, since the methods are not robust and lack the sensitivity to determine sub-ng/mL levels quantitatively, thereby hindering the exact evaluation of rat PK profiles. The objective of the present study was to develop a convenient, selective, sensitive and robust method for quantifying miglitol levels in rat plasma and to improve upon the analytical limitations of other methods.

Experimental Chemicals and materials Miglitol was purchased from Toronto Research Chemicals Inc. A stable iso2 tope-labeled internal standard (IS), H4-miglitol, was synthesized at Taisho Pharmaceutical Co. Ltd (Saitama, Japan). Distilled water (HPLC-grade) was obtained from Kanto Chemical (Tokyo, Japan). Acetonitrile (HPLC-grade), methanol (HPLC-grade) and ammonium acetate were obtained from Wako (Osaka, Japan). Ammonia solution (28%) was purchased from Koso Chemical (Tokyo, Japan). Blank rat plasma was purchased from Charles River Laboratories Japan (Kanagawa, Japan). MonoSpin C18-CX filter units were purchased from GL Sciences (Tokyo, Japan). The chemical structures of miglitol and its IS are shown in Fig. 1.

Instrument The LC-MS/MS system consisted of two Shimadzu LC-20AD pumps, a SIL-HTc autosampler, a CTO-10AC column oven (Shimadzu, Tokyo, Japan), and a TM Triple Quad 5500 mass spectrometer (AB SCIEX, Foster City, CA, USA). The data were collected and processed using Analyst® 1.6 software.

gas, 8 units; declustering potential, 10 V; entrance potential, 10 V; collision energy, 25 eV; collision cell exit potential, 12 V for miglitol and 14 V for IS, with a dwell time of 100 ms.

Preparation of calibration standards, matrix effect samples and QC samples Stock solutions of miglitol (100 μg/mL) and IS (100 μg/mL) were separately prepared in methanol. Working solutions of miglitol were prepared by serial dilution of the miglitol stock solution with distilled water. A 25 ng/mL IS working solution was prepared by diluting the IS stock solution with distilled water. To prepare the calibration standards for 0.5, 1, 3, 5, 10, 30, 50 and 100 ng/mL and the matrix effect samples, 10 μL of the miglitol working solution was added to 50 μL of blank rat plasma. To prepare the QC samples for 0.5, 0.8, 8 and 80 ng/mL, 45 μL of miglitol, QC solution was added to 4455 μL of blank rat plasma. To prepare the dilution QC samples at 300, 600 and 3000 ng/mL, an aliquot of stock solution was diluted with distilled water.

Sample preparation A 30 μL aliquot of distilled water was added to the blank sample and selectivity samples, while 10 μL of distilled water was added to the zero sample and QC samples (plasma volume, 50 μL each). A 20 μL aliquot of IS solution (25 ng/mL) was added to the zero sample, calibration standards, QC samples and samples for matrix effects (plasma volume, 50 μL each). A 200 μL aliquot of acetonitrile–28% ammonia solution (98:2, v/v) was added to all the samples, stirred for 30 s with a vortex mixer, and centrifuged (preset value, 10,600 x g, 4°C, 1 min). The supernatant was then collected and applied to a solid-phase extraction (SPE) cartridge (Mono Spin C18-CX) preconditioned with 200 μL of acetonitrile–28% ammonia solution (98:2, v/v). Miglitol and IS were eluted by centrifugation (preset value, 10,600 x g, 4°C, 1 min). An aliquot (5 μL) of eluate was then injected into the LC-MS/MS system.

Chromatographic conditions TM

Chromatographic separation was achieved using an XBridge Amide column (4.6 mm i.d. × 50 mm, 3.5 μm particle size; Waters, Milford, MA, USA) with 10 mmol/L ammonium acetate and acetonitrile–methanol (90:10, v/v) as the mobile phase under a gradient conditions at a flow rate of 0.5 mL/min. A linear gradient was applied as follows: increase from 5 to 35% 10 mmol/L ammonium acetate, 0–5.0 min; increase from 35 to 60%, 5.0–5.1 min; hold until 6.0 min; decrease from 60 to 5%, 6.0–6.1 min; hold until 9.0 min. The temperatures of the column and sample compartment were 70 and 10°C, respectively. The LC eluate was directed into the mass spectrometer from 3 to 5.5 min after injection.

Mass spectrometric conditions TM

A Triple Quad 5500 mass spectrometer with TurboIonSpray® (TIS) interface was operated in the positive ion mode for the selected reaction monitoring (SRM) LC-MS/MS analysis. The SRM channels that were monitored were m/z 208 → m/z 146 for miglitol and m/z 212 → m/z 176 for IS. The mass spectrometric conditions were optimized for both the analyte and IS as follows: TIS source temperature, 550°C; TIS voltage, 3000 V; curtain gas, 30 psi; nebulizing gas, 60 psi; TIS gas, 80 psi; collision

Method validation The method was validated for selectivity, sensitivity, linearity of the calibration curve, precision and accuracy, recovery, stability, dilution integrity and matrix effect according to the US Food and Drug Administration guidelines for bioanalytical method validation (US DHHS et al., 2001).

Application of the method to a rat PK study The developed LC-MS/MS method was used to determine the plasma concentrations of miglitol in 8-week-old male Sprague–Dawley rats (Charles River Laboratories, Japan) treated with single oral and intravenous doses of miglitol (1.5 mg/kg). Blood samples were collected in tubes containing sodium heparin at 0.083, 0.25, 0.5, 1, 2, 4, 8 and 24 h post-dosing, and the samples were centrifuged to obtain the plasma. The plasma samples were collected and stored at 80°C until analysis. The mean PK parameters were estimated using a noncompartmental model with WinNonlin 6.1 software (Pharsight, Mountain View, CA, USA).

Results and discussion Method development

Miglitol

2

H4-miglitol (IS)

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Figure 1. Chemical structures of miglitol and 2H4-miglitol (IS).

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A quantitative bioanalytical method for miglitol in rat plasma with a sub-ng/mL sensitivity is required to conduct PK/PD studies on miglitol in rats. LC-MS/MS is now widely used for pharmaceutical bioanalysis because of its outstanding sensitivity and selectivity. However, the quantitative analysis of monomeric sugars in biological fluids is very difficult to perform with a high sensitivity because of the high polarity, poor ionization and numerous matrix interferences causing ion suppression. Methods for quantifying miglitol in rat plasma using LC-MS/MS are scarce,

Copyright © 2014 John Wiley & Sons, Ltd.

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Sensitive LC-MS/MS method for the analysis of miglitol in rat plasma with only a few reports on the measurement of miglitol in human plasma. As an initial step in the development of an analytical method for quantifying miglitol in rat plasma, a previously published analytical method for measuring miglitol in human plasma (Li et al., 2007) was followed using rat plasma instead of human plasma. In the method, a 100 μL aliquot of a plasma sample was deproteinated with acetonitrile and washed with dichloromethane, then analyzed using a reverse-phase C18 column. However, our results were not sufficient, as the lower limit of quantification (LLOQ) was approximately 10 ng/mL and did not achieve the targeted subng/mL level (data not shown). Furthermore, the column deteriorated after several analytical runs, although the column was flushed

with pure water and methanol after each batch according to the published method. These problems were thought to be due to interference sources remaining in the injected sample obtained from the acetonitrile protein precipitation (PPT) and liquid–liquid extraction. The further removal of interference sources remaining in the injected sample was thus required. In the present study, we developed a more effective cleanup method for miglitol in biological fluid based on the physical properties of miglitol as follows: miglitol is not retained by a standard octadecyl sorbent because of its low logP value ( 2.7), its molecular form in an alkaline solution (≥9.0) and its ionic form in a neutral solution, since its pKb value is 8.22. The effectiveness of the combination of PPT and a unique SPE based

3.0e4 2.0e5

A

4.09

Intensity, cps

Intensity, cps

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3.07

1.0e4

4.64

1.2e5 8.0e4 4.0e4

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3.17 0.0

1.6e5

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4.92 6

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Intensity, cps

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0

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8

4.06

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C

6

0

2

4

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Intensity, cps

Intensity, cps

3.0e6 2.5e6 2.0e6 1.5e6 1.0e6

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Intensity, cps

1.8e6

Intensity, cps

8.0e4

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D

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1.6e5 1.2e5 8.0e4 4.0e4

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0

2

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Time, min

4

Time, min

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Copyright © 2014 John Wiley & Sons, Ltd.

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Figure 2. Representative chromatograms of miglitol and IS in rat plasma. (A) Zero sample; (B) 0.5 ng/mL lower limit of quantitation sample; (C) 100 ng/mL upper limit of quantitation sample; (D) 1 h post-dose sample following single oral dose of miglitol. Miglitol, left panel; IS, right panel.

A. Mizuno-Yasuhira et al. on a strategy of not ‘retention–cleanup–elution,’ but ‘passthrough–cleanup’ using a mixed-mode (C18/cation-exchange) cartridge was investigated. In the unique SPE, miglitol would pass through the cartridge, but the cationic interferences causing ion suppression would be retained by the cation-exchange sorbent that was bonded to the silica surface under conditions where an alkaline solvent was used for PPT and SPE. Furthermore, a nonpolar lipid, which was thought to pass through the cartridge if the sorbent was not mixed-mode but ion-exchange only and to cause the deterioration of the analytical column based on the results of our previous research for another monomeric sugar (Mizuno-Yasuhira et al., 2012), should be retained by the octadecyl group that is bonded to the silica surface of the mixed-mode cartridge. Consequently, the MonoSpin C18-CX mixed-mode cartridge, which has an octadecyl group and a sulfonic acid group for cation-exchange on the surface of its silica monolithic support, along with acetonitrile–28% ammonia solution (98:2, v/v) as a solvent for PPT and preconditioning SPE, were selected. This method allowed the successful removal of both cationic interference sources and lipophilic components simultaneously, enabling a good recovery rate for the analyte with a lower variation, as we expected. The proposed analytical columns included both amino and amide columns, as these columns are suitable for the analysis of monomeric sugars in general. The XBridgeTM amide column was ultimately selected because its durability against alkaline injection solvents was higher than that of an amino column. Furthermore, the XBridgeTM amide column can be used at high temperatures to collapse anomers into one peak. The chromatographic separation of miglitol from the interference peaks was achieved using not acetonitrile, but acetonitrile– methanol (90:10, v/v) with 10 mmol/L of ammonium acetate as the mobile phase under a gradient condition at a flow rate of 0.5 mL/min (data not shown). The SRM channels monitored were m/z 208 → m/z 146 for miglitol and m/z 212 → m/z 176 for IS. From a bioanalysis point of view, the SRM transition of a stable-isotope labeled IS should be set based on the analyte of interest. Interferences, however, were observed in the SRM transition of m/z 212 → m/z 150 for the IS; therefore, a different transition was selected and set. These optimized conditions described above enabled a good selectivity and a high sensitivity (sub-ng/mL level) to be achieved for the evaluation of rat PK profiles, and the durability

of the analytical column was improved, enabling a large sample analysis. Typical chromatograms are shown in Fig. 2. Method validation Selectivity. The presence of interfering peaks was considered in the SRM chromatograms of blank plasma samples from six different sources. Typical SRM chromatograms for a zero sample and calibration standards (0.5 and 100 ng/mL) are shown in Fig. 2. Miglitol and IS were eluted with good peak shapes. No interfering peak was observed at each eluting position of miglitol and IS in any of the blank rat plasma samples that were studied. Linearity of calibration curve. Calibration standards at concentration levels of 0.5, 1, 3, 5, 10, 30, 50 and 100 ng/mL for miglitol in rat plasma (n = 1 for each level) were assayed on three different days. Calibration curves were obtained from the relationship between the peak area ratios of miglitol to the IS and the nominal concentrations of miglitol using the least squares method (with 1/x2 weighting). The linearity (correlation coefficient: r) of the calibration curves and the accuracy (relative error, RE) of the back-calculated value at each calibration standard level were evaluated. The parameters of the calibration curves are shown in Table 1. The calibration curves for miglitol in rat plasma were linear over the concentration range of 0.5–100 ng/mL, with correlation coefficients ≥0.9984. The accuracy for each calibration standard level ranged from 9.4 to +8.7%. Precision and accuracy. The intra-assay precision and accuracy for this method were determined by analyzing QC samples at four concentration levels (n = 5 for each level). The inter-assay precision and accuracy were also determined by analyzing QC samples in three batches on different days. The precision and accuracy were presented as coefficient of variation (CV) and RE, respectively. The intra-assay precision and accuracy ranged from 0.6 to 3.3% and from 4.8 to 3.4%, respectively. The inter-assay precision and accuracy ranged from 1.7 to 3.3% and from 5.0 to +3.0%, respectively (Table 2). Lower limit of quantification (LLOQ). The LLOQ was defined as the lowest concentration on the calibration curve where the analyte can be measured with a precision of ≤20.0%, an

Table 1. Calibration curves for miglitol in rat plasma Analyte

Miglitol

Nominal concentration (ng/mL) 0.5 1 3 5 10 30 50 100

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Slope y-Intercept r: Correlation coefficient

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Back-calculated concentration (ng/mL)

Relative error (%)

First day

Second day

Third day

First day

0.492 1.01 3.09 5.20 10.2 30.5 49.3 90.6

0.496 0.997 3.11 5.15 10.1 30.1 49.8 93.4

0.492 1.00 3.26 5.13 10.1 29.7 49.8 90.8

1.6 1.0 3.0 4.0 2.0 1.7 1.4 9.4

0.253 0.00921 0.9988

0.252 0.01060 0.9993

Second day 0.8 0.3 3.7 3.0 1.0 0.3 0.4 6.6

Third day 1.6 0.0 8.7 2.6 1.0 1.0 0.4 9.2

0.260 0.01400 0.9984

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Sensitive LC-MS/MS method for the analysis of miglitol in rat plasma Table 2. Precision and accuracy for the determination of miglitol in rat Analyte

Nominal concentration (ng/mL)

Miglitol

0.5 0.8 8 80

Intra-assay (n = 5) CV (%)

RE (%)

CV (%)

RE (%)

0.6 3.3 1.1 1.1

1.4 +0.8 +3.4 4.8

2.2 3.3 1.5 1.7

1.8 0.4 +3.0 5.0

accuracy of ≤ ±20.0%, and a signal-to-noise ratio of at least 5:1. Based on the evaluation results for selectivity (Fig. 2) and precision and accuracy (Table 2), the LLOQ of miglitol in rat plasma was determined to be 0.5 ng/mL. Recovery. The extraction recovery of miglitol from rat plasma was determined at three concentrations (0.8, 8 and 80 ng/mL, n = 5 for each level) by comparing the peak area ratios (miglitol/IS) of the QC samples (spiked before extraction) with those of the corresponding samples spiked post-extraction. In a similar manner, the recovery of the IS was also evaluated at 25 ng/mL, based on the peak area ratios (IS/miglitol). The results of the evaluation for recovery are shown in Table 3. The extraction recovery of miglitol ranged from 74.7 to 75.6%,

Table 3. Recoveries of miglitol and IS from rat plasma Analyte

Miglitol (n = 5)

IS (n = 5)

Nominal concentration (ng/mL) 0.8 8 80 25

Inter-assay (n = 15)

Recovery (%)

SD

CV (%)

74.7 75.6 75.5 78.5

1.7 1.2 1.1 1.6

2.2 1.6 1.5 2.0

with a CV ≤2.2%. The IS recovery from rat plasma was 78.5%, with a CV of 2.0%. Stability. The stability of miglitol in rat plasma was assessed using QC samples at concentration levels of 0.8 and 80 ng/mL (n = 3 for each level) and was considered acceptable when the remaining percentage in the concentration was 85–115% of the initial values. The stability results in plasma samples are shown in Table 4. In rat plasma, miglitol was stable at room temperature for at least 6 h, at 20 and 80°C for at least 16 weeks, and throughout the course of three freeze–thaw cycles from 20°C to room temperature and from 80°C to room temperature. Miglitol was also found to be stable in processed samples stored in the LC sample compartment at 10°C for at least 72 h. Dilution integrity. To investigate the ability to dilute plasma samples containing miglitol, dilution QC samples were created at concentration levels of 300, 600 and 3000 ng/mL, diluted by 5-, 10- or 50-fold with blank rat plasma, and then analyzed in triplicate. The precision and accuracy observed for dilutions of 5-, 10- or 50-fold were acceptable in rat plasma, as shown in Table 5. Matrix effect. Samples (six individuals, n = 1 each) for matrix effects at a concentration level of 0.8 ng/mL for miglitol were analyzed. The evaluation results for the matrix effects are shown in Table 6.

Table 4. Stability of miglitol in rat plasma Analyte

Miglitol (n = 3)

Nominal concentration (ng/mL)

Mean of calculated concentration (ng/mL)

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0.824 75.1

103.4 101.1

0.827 74.8

103.8 98.7

0.798 75.7

99.3 99.0

0.784 76.9

99.0 101.5

0.796 77.5

100.5 102.2

0.822 77.5

103.8 102.2

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Freeze–thaw stability ( 20°C, three cycles) 0.8 80 Freeze–thaw stability ( 80°C, three cycles) 0.8 80 Short-term stability (room temperature for 6 h) 0.8 80 Long-term stability ( 20°C for 16 weeks) 0.8 80 Long-term stability ( 80°C for 16 weeks) 0.8 80 Post-preparative stability (10°C for 72 h) 0.8 80

Remaining (%)

A. Mizuno-Yasuhira et al. Table 5. Influence of dilution with rat plasma Analyte

Nominal concentration (ng/mL)

Miglitol (n = 3)

Dilution factor

300 600 3000

Mean of calculated concentration (ng/mL)

×5 ×10 ×50

SD

290 578 2856

CV (%)

1.6 6 30

RE (%)

0.6 1.0 1.1

3.3 3.6 4.8

Table 6. Matrix effect for the determination of miglitol in rat plasma Analyte

Nominal concentration (ng/mL)

Miglitol

Observed concentration (ng/mL)

0.8

0.800 0.815 0.803 0.765 0.835 0.799

10000

Concentration (ng/mL)

0.803

SD

CV (%)

0.023

2.9

RE (%) 0.0 1.9 0.4 4.4 4.4 0.1

Table 7. Pharmacokinetic parameters after a single oral and intravenous administration of miglitol (1.5 mg/kg) to rats

oral 1000

Mean of calculated concentration (ng/mL)

intravenous

100

10

1

0.1 0

4

8

12

16

20

24

Time (h) Figure 3. Plasma concentration–time profiles of miglitol following single oral and intravenous administrations of 1.5 mg/kg to rats. Data are expressed as means ± SD (oral n = 6; intravenous n = 3).

The precision (CV) for 0.8 ng/mL samples, prepared with blank rat plasma from six individuals, was 2.9%, with an accuracy ranging from 4.4 to 4.4% for miglitol. The results met the validation acceptance criteria.

Pharmacokinetic parameter

Intravenous administration (n = 3) Mean±SD

Oral administration (n = 6) Mean±SD

CLtotal (mL/h/kg) Vdss (mL/kg) t1/2 (h) Cmax (ng/mL) Tmax (h) AUC0-t (ng h/mL) AUC0-∞ (ng h/mL) Bioavailability (%)

1170±220 942±421 4.2±23 — — 1310±223 1320±223

— — 2.8±2.1 867±173 0.46±0.10 905±77.9 909±78.6 68.9

CLtotal, total plasma clearance; Vdss, volume of distribution; t1/2, terminal half-life; Cmax, maximum level; Tmax, time of Cmax; AUC0-t, area under the curve from zero to time t; AUC0-∞, area under the curve from zero to infinity published value (Ahr et al., 1997) after the administration of 3 H-miglitol. Our accurate PK data is the first to be reported using nonradioisotope-labeled miglitol and is likely to be valuable for further PK/PD studies of miglitol (Table 7).

Application of the developed method to a rat PK study

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The LC-MS/MS method described above was applied successfully to PK studies after the single administration of miglitol (1.5 mg/kg) to rats. All the QC samples were found to be within acceptable limits for precision and accuracy. The plasma concentration–time profiles of miglitol in male rats are shown in Fig. 3. Following the intravenous administration of miglitol to fasted male rats, the plasma levels appeared to decline, with a terminal half-life (t1/2) of 4.2 h and a total plasma clearance of 1170 mL/h/kg. The volume of distribution was estimated to be 942 mL/kg. After the oral administration of miglitol to fasted male rats, the plasma concentration reached a maximum level (Cmax) of 867 ng/mL at 0.46 h, then declined with a t1/2 of 2.8 hours. The AUC0-t was 905 ng · h/mL, which corresponds to 70% of the dose-normalized

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Conclusion A convenient, selective, sensitive and robust LC-MS/MS method for the quantification of miglitol in rat plasma was developed and validated over a concentration range of 0.5–100 ng/mL of plasma. To the best of our knowledge, this is the first method for quantifying miglitol and enabling the establishment of accurate PK profiles in rats that does not require the use of radioisotope-labeled compounds. The availability of this proposed bioanalytical approach may be helpful for the precise pharmacodynamic evaluation of miglitol. Furthermore, the present preparation strategy for the quantification of a monomeric sugar in biological fluid using LC-MS/MS should be useful for other monomeric sugar analyses.

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Sensitive LC-MS/MS method for the analysis of miglitol in rat plasma

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Biomed. Chromatogr. 2014; 28: 1423–1429

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A sensitive and selective method for the quantitative analysis of miglitol in rat plasma using unique solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry.

A sensitive, selective and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of miglitol in...
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