Comparative Pharmacokinetic Assessment of Once-Daily Extended-Release and Twice-Daily Amantadine Formulations in Healthy Male Subjects Under Fasting Conditions.

The shortcomings of synucleinopathy-based Parkinson disease staging highlight the need for systematic clinicopathologic elucidation and biomarkers. In this study, we investigated associations of proteinopathy and inflammation markers with changes in gray matter volume that accompany Parkinson disease progression. We prospectively enrolled 42 patients with idiopathic Parkinson disease, subdivided into early-/late-stage groups and 27 healthy controls. Parkinson disease severity and participants' functional and cognitive performance were evaluated. Peripheral plasma α-synuclein, β-amyloid42, and tau were quantified with immunomagnetic reduction assays, and nuclear DNA by polymerase chain reaction, and regional gray matter volumes were determined by MR imaging. Statistical tests identified stage-specific biomarkers and gray matter volume patterns in the early-stage Parkinson disease, late-stage Parkinson disease, and control groups. Correlations between gray matter volume atrophy, plasma biomarkers, Parkinson disease severity, and cognitive performance were analyzed. Patients with Parkinson disease had significantly elevated α-synuclein, tau, and β-amyloid42 levels compared with controls; nuclear DNA levels were similar in early-stage Parkinson disease and controls, but higher in late-stage Parkinson disease (all P < .01). We identified 3 stage-specific gray matter volume atrophy patterns: 1) control > early-stage Parkinson disease = late-stage Parkinson disease: right midfrontal, left lingual, and fusiform gyri, left hippocampus, and cerebellum; 2) control > early-stage Parkinson disease > late-stage Parkinson disease: precentral, postcentral, parahippocampal, left superior-temporal, right temporal, right superior-frontal, and left cingulate gyri, occipital lobe, and bilateral parts of the cerebellum; 3) control = early-stage Parkinson disease > late-stage Parkinson disease: left midfrontal, superior-frontal and temporal, amygdala, and posterior cingulate gyri, caudate nucleus, and putamen. We discovered stage-specific correlations among proteinopathy, inflammation makers, topographic gray matter volume patterns, and cognitive performance that accompanied Parkinson disease progression. Identifying associations linking peripheral plasma biomarkers, gray matter volume, and clinical status in Parkinson disease may facilitate earlier diagnosis and improve prognostic accuracy.

Randomized, open-label, two-period crossover comparison of the pharmacokinetic and pharmacodynamic properties of two amlodipine formulations in healthy adult male Korean subjects

Evidence That Brain MAO A Activity Does Not Correspond to MAO A Genotype in Healthy Male Subjects

The study was conducted to find out whether the bioavailability of a 500 mg azithromycin (CAS 83905-01-5) tablet (Zycin, test) was equivalent to that of a reference formulation. The pharmacokinetic parameters assessed in this study were the area under the plasma concentration-time curve from time zero to 120 h (AUCt), area under the plasma concentration-time curve from time zero to infinity (AUCinf), the peak plasma concentration of the drug (Cmax), time needed to achieve the peak plasma concentration (tmax), and the elimination half-life (t1/2). This was a randomized, single blind, two-period, cross-over study which included 18 healthy adult male and female subjects under fasting conditions. In each of the two study periods (separated by a washout of two weeks) a single dose of test or reference drug was administered. Blood samples were taken up to 120 h post dose, the plasma was separated and the concentrations of azithromycin were determined by a LC-MS/MS method. In this study, the mean AUCt, AUCinf, Cmax, and t1/2 of azithromycin from the test drug were 4967.49 ng x h x mL(-1), 5871.74 ng x h x mL(-1), 412.14 ng/mL, and 51.32 h, respectively. The mean AUCt, AUCinf, Cmax, and t1/2 of azithromycin from the reference drug were 4276.75 ng x h x mL(-1), 5578.12 ng x h x mL(-1), 419.89 ng/mL, and 51.23 h, respectively. The median tmax of he test drug and reference drug were 3.0 h and 2.0 h, respectively. The geometric mean ratios (90% CI) of the test drug/reference drug for azithromycin were 101.56% (86.61-119.08%) for AUCt, 101.27% (84.97-120.70%) for AUCinf, and 97.78% (84.50-113.16%) for Cmax. Based on this study, it was concluded that the two azithromycin tablets (test and reference drug) were bioequivalent in terms of the rate and extent of absorption.

The purpose of this study was to find out whether the bioavailability of a 550 mg naproxen sodium (CAS 22204-53-1 ) tablet (Sunprox, test) produced by Sunward Pharmaceutical Sdn Bhd was equivalent to that produced by the innovator.The pharmacokinetic parameters assessed in this study were area under the plasma concentration-time curve from time zero to 72 hours (AUC t ), area under the plasma concentration-time curve from time zero to infinity (AUC inf ), the peak plasma concentration of the drug (C max ), time needed to achieve the peak plasma concentration (t max ), and the elimination half life (t 1/2 ).This was a randomized, single blind, two-period, cross-over study which included 26 healthy adult male and female subjects under fasting conditions.In each of the two study periods (separated by a washout of one week) single dose of test or reference drug was administered.Blood samples were taken up to 72 h post dose, the plasma was separated and the concentration of naproxen were determined by HPLC-UV method.In this study, the mean AUC t , AUC inf , C max , and t ½ of naproxen from the test drug were 936.11 µg.h.mL -1 , 977.03 µg.h.mL -1 , 76.55 µg/mL, and 15.11 h, respectively.The mean AUC t , AUC inf , C max , and t ½ of naproxen from the reference drug were 969.77µg.h.mL -1 , 1013.72 µg.h.mL -1 , 75.92 µg/mL, and 15.11 h, respectively.The median t max of he test drug and reference drug were 3.0 h and 2.0 h, respectively.The geometric mean ratios (90% CI) of the test drug/ reference drug for naproxen were 96.46% (94.30-98.66%) for AUC t , 96.33% (94.03 -98.69%) for AUC inf , and 100.37% (95.90 -105.05%) for C max .Based on this study, it can be concluded that the two naproxen sodium tablets (test and drug reference drug) were bioequivalent in term of the rate and extent of absorption.

PurposeThe current study aimed to evaluate whether a generic product of etoricoxib 120 mg film-coated tablet (the test drug) was bioequivalent to the reference product (Arcoxia® film-coated tablet 120 mg).MethodsThis was a randomized, open-label, two-sequence, crossover study under fasting condition, with a 14-day washout period, involving 26 healthy adult male and female subjects. Blood samples were taken and analyzed for plasma concentrations of etoricoxib (Chemical s Service [CAS] 202409-33-4) using a high-pressure liquid chromatography–ultraviolet detector (HPLC-UV) system capable of measuring etoricoxib concentrations ranging from 5.00 to 5002.90 ng/mL, with the lowest limit of quantitation of 5.00 ng/mL. A noncompartmental method was used to determine the pharmacokinetic parameters of a single-dose administration of the drug, including the area under plasma concentration–time curve from time zero to the time of last observed concentration (AUC0−t), the area under plasma concentration–time curve from time zero to infinity (AUC0−∞), the maximum plasma concentration (Cmax), the time to reach the maximum plasma concentration (tmax), and the terminal half-life (t½).ResultsAfter a single-dose administration of etoricoxib 120 mg film-coated tablet, the mean (SD) values for the AUC0–72h and Cmax of the test drug were 45913.42 (13142.19) ng·h/mL and 3155.93 (752.81) ng/mL, respectively; the values for the reference drug were 44577.20 (13541.85) ng·h/mL and 2915.13 (772.81) ng/mL, respectively. The geometric mean ratios (90% CIs) of the test drug/reference drug were 103.40% (98.70%–108.32%) for AUC0–72h and 109.26% (100.18%–119.18%) for Cmax. No clinically significant differences in tmax and t½values were found between the test drug and the reference drug. No adverse events were experienced by the subjects during this study.ConclusionThe present study demonstrated that the evaluated generic etoricoxib 120 mg film-coated tablets were bioequivalent to the reference drug.

The purpose of this study was to find out whether the bioavailability of 100 mg minocycline capsule manufactured by Y.S.P. Industries (M) Sdn. Bhd. was equivalent to that produced by Apotex Canada (Apo-Minocycline ® 100 mg). The pharmacokinetic parameters assessed in this study were area under the plasma concentration-time curve from time zero to the last observed quantifiable concentration (AUC t ), area under the plasma concentration-time curve from time zero to infinity (AUC inf ), the peak plasma concentration of the drug (C max ), time needed to achieve the peak plasma concentration (t max ), and the elimination half life (t 1/2 ). These parameters were determined on plasma concentrations of minocycline. This was a randomized, single blind, two-period, two-sequence crossover study which included 20 healthy adult male and female subjects under fasting conditions. In each of the two study periods (separated by a washout of one week) single dose of test or reference drug was administered. Blood samples were taken up to 60 h post dose, the plasma was separated and the concentration of minocycline were determined by HPLC-UV method. In this study, the mean (SD) AUC t, AUC inf , C max , and t ½ of minocycline from the test drug were 17272.46 (3316.80) ng.h.mL -1 , 19438.68 (3862.36) ng.h.mL -1 , 938.75 (192.92) ng/mL, and 19.46 (4.90) h, respectively, with the median (range) t max of minocycline from the test drug was 2.00 (0.67 – 3.00) h. The mean (SD) AUC t , AUC inf , C max , and t ½ of minocycline from the reference drug were 16999.33 (3103.27) ng.h.mL -1 , 19078.66 (3401.97) ng.h.mL -1 , 944.19 (188.56) ng/mL, and 18.90 (4.84) h, respectively, with the median (range) t max of minocycline from the reference drug was 2.00 (1.00 – 3.00) h. The geometric mean ratios (90% C.I.) of the test drug/reference drug for minocycline were 101.36% (97.85 – 105.00%) for AUC t, 101.53% (98.31 – 104.85%) for AUC inf , and 99.22% (95.92 – 102.63%) for C max , respectively. Based on this study, it can be concluded that the two minocycline capsules (test and drug reference drug) were bioequivalent in term of the rate and extent of absorption.

The present study was performed to compare the bioavailability of two clopidogrel 75 mg film-coated tablet formulations (test formulation and reference formulation). This study was a randomized, single-blind, two-period, two-sequence cross-over study which included 24 healthy adult male and female subjects under fasting condition. The pharmacokinetic parameters were assessed based on the concentrations of clopidogrel (CAS 120202-66-6) parent compound. In each of the two study periods (separated by a washout of one week) a single dose of test or reference drug was administered. Plasma concentrations of the drug were determined by LC-MS/MS method. The pharmacokinetic parameters assessed in this study were area under the plasma concentration-time curve from time zero to 24 h (AUCt), area under the plasma concentration-time curve from time zero to infinity (AUCinf), the peak plasma concentration of the drug (Cmax), time needed to achieve the peak plasma concentration (t(max)), and the elimination half life (t1/2). The geometric mean ratios (90% CI) of the test drug/reference drug for clopidogrel parent compound were 95.19% (81.63-110.90%) for AUCt, 95.55% (80.50-113.42%) for AUCinf, and 100.18% (80.87-124.09%) for Cmax. The 90% confidence intervals calculated for AUCt and Cmax of clopidogrel parent compound were within the standard bioequivalence range (80-125% for AUC and Cmax). It was concluded that the two clopidogrel film-coated tablets (test and reference drug) were bioequivalent in terms of the rate and extent of absorption.

The bioequivalence study was conducted to compare the bioavailability of two rosuvastatin 20 mg film-coated tablet formulations (test and reference formulation). This study was an open-label, randomized, single-dose, two-periods, twotreatments, and crossover study which included 32 healthy adult male and female subjects under fasting conditions. Each of the two study periods was separated by a 7 days washout period. A single oral dose of test or reference drug was administered to the subject in each period based on the randomization scheme. Plasma concentrations of the drug were determined by LC-MS/MS method. The pharmacokinetic parameters assessed in this study were the area under the plasma concentration-time curve from time zero to 72 h (AUC0-72h), area under the plasma concentration-time curve from time zero to infinity (AUC0-∞), the peak plasma concentration of the drug (Cmax), time needed to achieve the peak plasma concentration (Tmax), and the elimination half-life (T1/2). The geometric mean ratio (GMR) and 90% Confidence Interval (90% CI) for AUC0-72h and Cmax of test/reference drug for rosuvastatin were 97.05 % (89.07%– 105.74%) and 101.15% (89.53%– 114.26%). Since the 90% CI with α 0.05% for AUC0-72h and Cmax of rosuvastatin were within the standard bioequivalence range (80.00– 125.00%), it was concluded that the two rosuvastatin film-coated tablets (test and reference drug) were bioequivalence in terms of the rate and extent of absorption.

The present study was conducted to compare the bioavailability of two etoricoxib 90 mg film-coated tablet formulations (test formulation and reference formulation). This study was an open-label, randomized, single-dose, two-periods, twotreatments, and crossover study which included 24 healthy adult male and female subjects under fasting conditions. Each of the two study periods was separated by a 7 days washout. A single dose of test or reference drug was administered to the subject in each period based on the randomization scheme. Plasma concentrations of the drug were determined by LC-MS/MS method. The pharmacokinetic parameters assessed in this study were the area under the plasma concentration-time curve from time zero to 96 h (AUC0-96h), area under the plasma concentration-time curve from time zero to infinity (AUC0-∞), the peak plasma concentration of the drug (Cmax), time needed to achieve the peak plasma concentration (Tmax), and the elimination half-life (T1/2). The geometric mean ratios (90% CI) of the test drug/reference drug for etoricoxib were 102.39% (97.63% – 107.38%) for AUC0-96h and 93.23% (86.54% – 100.43%) for Cmax. The 90% Confidence Intervals (CI) calculated for AUC0-96h and Cmax of etoricoxib were within the standard bioequivalence range (80.00– 125.00% for AUC0-t and Cmax). It was concluded that the two etoricoxib film-coated tablets (test and reference drug) were bioequivalent in terms of the rate and extent of absorption

The present study was performed to compare the bioavailability of two perindopril erbumine (CAS 107133-36-8) 4 mg tablet formulations (test formulation and reference formulation). This study was a randomized, single-blind, two-period, two-sequence cross-over study which included 20 healthy adult male and female subjects under fasting conditions. In this study, one subject withdrew from the study and one reserve subject did not appear at both periods. The pharmacokinetic parameters were assessed based on the concentrations of perindopril (CAS 82834-16-0) and perindoprilat (CAS 95153-31-4) because perindopril has litte pharmacologic activity until hydrolized in the liver into its active metabolite, perindoprilat. The blood samples from 18 subjects were analyzed for plasma concentrations of perindopril and perindoprilat. In each of the two study periods (separated by a washout of three weeks) a single dose of test or reference drug was administered. Plasma concentrations of the drug were determined by LC-MS/MS method. The pharmacokinetic parameters assessed in this study were area under the plasma concentration-time curve from time zero to 192 h (AUC), area under the plasma concentration-time curve from time zero to infinity (AUCinf), the peak plasma concentration of the drug (Cmax time needed to achieve the peak plasma concentration (tmax), and the elimination half-life (t(1/2)). The geometric mean ratios (90% CI) of the test drug/reference drug for perindopril and perindoprilat were 106.59% (92.97-122.20%) and 100.56% (94.11-107.46%) for AUC,, 106.64% (93.39-121.77%) and 100.88% (95.30-106.80%) for AUCinfo, and 101.23% (87.39-117.27%) and 99.30% (90.42-109.05%) for Cmax, respectively. The 90% confidence intervals calculated for AUCt and Cmax of perindopril and perindoprilat were within the standard bioequivalence range (80-125% for AUC and Cmax). It was concluded that the two perindopril erbumine tablets (test and reference drug) were bioequivalent in terms of the rate and extent of absorption.

Introduction: Napabucasin is an NQO1-bioactivatable investigational agent hypothesized to affect multiple oncogenic cellular pathways including pSTAT3 through the generation of reactive oxygen species. The primary objectives of this phase 1, open-label study in healthy male subjects were to characterize the absorption, metabolism, and excretion of 14C-napabucasin and to determine the pharmacokinetics of 14C-napabucasin and relevant metabolites in plasma, urine, and feces. The secondary objective was to assess safety and tolerability of napabucasin. Methods: Healthy male adult (age 18–45 years) subjects were eligible to receive a single oral 240-mg dose of napabucasin containing ~100 μCi of 14C-napabucasin. Blood, urine, and feces were collected up to 264 hours (h; 11 days) postdose. Whole blood, plasma, urine, fecal, and expired air samples were assayed for total radioactivity (TR). Plasma, urine, and fecal samples were assayed for napabucasin and metabolites. Results: Overall, 8 subjects (mean [range] age 29 [23–39] years) were enrolled. The mean TR recovered was 81.1%. In general, elimination of 14C-napabucasin was predominantly via feces (57.2%), to a lesser extent via urine (23.8%), and was negligible in expired air. Most (76.0%) recovery was within 48 h postdose. 14C-napabucasin was rapidly absorbed (median time to peak concentration 2.8 h) and underwent extensive reductive metabolism to yield dihydro-napabucasin (M1), the sole major circulating metabolite. Systemic exposure to 14C-napabucasin was higher than M1, and M1 plasma concentration versus time profiles generally mirrored 14C-napabucasin. Similar arithmetic mean half-lives for 14C-napabuscasin and M1 (7.9 h and 7.1 h, respectively) suggest that the rate of formation of the reduced metabolite is rate limiting. The TR whole blood:plasma ratio of 0.4 indicated that circulating drug-related compounds were essentially confined to plasma. Four minor metabolites were identified but accounted for ≤7.0% of TR in plasma. Consistent with preclinical animal models, no uniquely human or disproportionate metabolite was quantified. Secondary glucuronide and sulfate conjugates were common urinary metabolites. These data suggest that 14C-napabucasin was mainly cleared by reductive metabolism and, to a lesser extent, by renal elimination. 14C-napabucasin and M1 recovered in urine accounted for 13.2% and 9.6% of the administered dose, respectively. Apparent renal clearance of 14C-napabucasin and M1 were 8.1 L/h and 7.9 L/h, respectively. All subjects experienced treatment-emergent adverse events (TEAEs). All TEAEs were mild (grade 1) and the majority were assessed as related to napabucasin. The most commonly reported TEAEs were gastrointestinal disorders and, of these, diarrhea was reported most frequently and generally started within 4.5–5.0 h postdose and resolved without treatment. There were no clinically significant laboratory, vital sign, electrocardiogram, or physical examination changes. Conclusions: 14C-napabucasin is primarily excreted through feces. 14C-napabucasin underwent extensive metabolism to yield M1 as the sole major circulating metabolite. No uniquely human or disproportionate metabolite was quantified. A single oral 240-mg dose of napabucasin was tolerated in healthy male subjects. Citation Format: Xiaoshu Dai, Michael D Karol, Matthew Hitron, Marjie Hard, J Evan Blanchard, Nicola Eraut, Natalie Rich, Brandon Gufford. Mass balance and pharmacokinetics of an oral dose of 14C-napabucasin in healthy adult male subjects [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A113. doi:10.1158/1535-7163.TARG-19-A113

e13009 Background: PERT-IJS is a proposed biosimilar to reference pertuzumab (PERT). This study assessed the pharmacokinetic (PK) equivalence, safety, tolerability, and immunogenicity of PERT-IJS compared with EU-approved PERT (EU-PERT) and US-licensed PERT (US-PERT) and EU-PERT versus US-PERT. Methods: In this double-blind, three-arm, parallel group, Phase 1 study, healthy male subjects were randomized 1:1:1 to 60±5 mins of a single 420 mg intravenous infusion of PERT-IJS (n = 50), EU-PERT (n = 50), or US-PERT (n = 49). Sentinel dosing with one subject from each treatment arm was performed initially to ensure optimal safety. PK, safety, and immunogenicity were evaluated for 91 days after dosing. The primary endpoint was area under the serum concentration–time curve (AUC) from time 0 to infinity (AUC 0-∞ ), and secondary endpoints were maximum serum concentration (C max ) and AUC from time 0 to the last measurable concentration at time t (AUC 0-t ) for pertuzumab. The pre-defined equivalence criterion was a 90% confidence interval (CI) of 80.00–125.00% for ratios of geometric least squares means (LSMs) among the test and reference products. Safety data were collected throughout the study and analyzed descriptively. Results: A total of 149 subjects, mean age 41.6 years, were randomized to the study treatments. The 90% CIs of the ratios of geometric LSMs were within the pre-defined bioequivalence interval of 80.00-125.00% for the primary and secondary endpoints (Table). Safety and tolerability profiles were also comparable among the treatment groups. The anti-drug antibody rates were comparable in all three treatment groups. Conclusions: This study demonstrated PK bioequivalence as well as comparable safety, tolerability, and immunogenicity between PERT-IJS versus EU-PERT/US-PERT and EU-PERT versus US-PERT in healthy male subjects. Clinical trial information: 2022-001691-34 . Statistical results of pertuzumab pharmacokinetics parameters. Treatment Comparison PK Parameter Geometric Least Squares Means Ratio 90% Confidence Interval PERT-IJS/EU-PERT AUC 0-∞ (mcg·h/mL) 0.97 91.48%-103.34% PERT-IJS/US-PERT AUC 0-∞ (mcg·h/mL) 0.94 88.25%-99.69% EU-PERT/US-PERT AUC 0-∞ (mcg·h/mL) 0.96 90.74%-102.55% PERT-IJS/EU-PERT AUC 0-t (mcg·h/mL) 0.97 91.39%-103.32% PERT-IJS/US-PERT AUC 0-t (mcg·h/mL) 0.94 88.06%-99.56% EU-PERT/US-PERT AUC 0-t (mcg·h/mL) 0.96 90.61%-102.47% PERT-IJS/EU-PERT C max (mcg/mL) 1.00 94.28%-106.01% PERT-IJS/US-PERT C max (mcg/mL) 0.97 91.70%-103.12% EU-PERT/US-PERT C max (mcg/mL) 0.97 91.71%-103.16%

Objective: To assess the pharmacokinetics and bioequivalence of Dapagliflozin 10mg + Vildagliptin Sustained Release (SR) 100mg + Metformin SR 1000mg fixed dose combination (FDC) tablets with DAPAMAC V 10 (Dapagliflozin 10mg + Vildagliptin SR 100mg tablets) and Glycomet 1g (Metformin SR 1000 mg tablets) in healthy adult male subjects under fasting conditions. Material and Methods: This was an open-label, balanced, randomized, two-treatment, two-period, two-sequence, single-dose, crossover, oral bioequivalence study. Volunteers were randomized to receive either a test product or a reference product under the fasting condition with a seven-day washout period. The pharmacokinetics parameters evaluated were maximum plasma concentration (Cmax), the area under the curve (AUC) at time t (AUC0-t), and the total area under the curve (AUC0-∞). Adverse events were also assessed as safety endpoints. Results: Twenty-four healthy adult male subjects were randomized, and 24 completed the study. The mean values for Cmax, AUC0-t, and AUC0-∞ were almost identical for test and reference products. The 90% confidence intervals of the ratios of adjusted geometric means for the pharmacokinetic parameters, i.e. Cmax, AUC0-t, and AUC0-∞ of the test product, were within the predefined bioequivalence limits of 80.00 to 125.00%. No adverse events or serious adverse events or deaths were reported during the study. All treatments were well tolerated. Conclusion: The test formulation, Dapagliflozin 10mg + Vildagliptin SR 100mg + Metformin SR 1000mg FDC, were bioequivalent to DAPAMAC V 10 (Dapagliflozin 10mg + Vildagliptin SR 100mg tablets) and Glycomet 1g (Metformin 1000mg SR tablets) in healthy adult male subjects under fasting conditions. Keywords: Bioequivalence, Fixed-Dose Combination, Dapagliflozin, Metformin, Sustained Release, Vildagliptin, AUC, Cmax

BackgroundThe current study was conducted to find out whether two oral preparations of 300 mg gabapentin (the test and reference capsules) were bioequivalent.Subjects and methodsThis was a randomized, single-blind, crossover study under fasting condition, with a 7-day washout period, which included 37 healthy adult male and female subjects. After an overnight fast, subjects were given, orally, one capsule of the test drug or of the reference drug. Blood samples were drawn immediately before taking the drug, then at 20 and 40 minutes, and 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 12, 15, and 24 hours after dosing, to evaluate pharmacokinetic parameters of the single dose administration, ie, the area under the plasma concentration–time curve (AUC) from time zero to 24 hours (AUCt), AUC from time zero to infinity (AUCinf), the peak plasma concentration of the drug (Cmax), time needed to achieve Cmax (tmax), and the elimination half-life (t1/2). The plasma concentrations of gabapentin were determined using validated high-performance liquid chromatography with ultraviolet detection.ResultsThe geometric mean ratios (90% confidence interval) of the test drug/reference drug for gabapentin were 103.15% (90.38%–117.72%) for AUCt, 103.53% (90.78%–118.07%) for AUCinf, and 108.06% (96.32%–121.24%) for Cmax. The differences in tmax and t1/2 values between the test and reference drug products for gabapentin were not statistically significant. Light-headedness, nausea, and headache were encountered during the study, but they were all mild and well tolerated. The 90% confidence intervals of the test/reference AUC ratio and Cmax ratio of gabapentin were within the acceptance range for bioequivalence.ConclusionThe two preparations of gabapentin 300 mg capsule were bioequivalent, thus both can be used interchangeably in the clinical setting.