Yong-Jin Im

Effects of Ficus carica paste on loperamide-induced constipation in rats.

OBJECTIVE Constipation is one of the most common gastrointestinal complaints worldwide. This study examined the effects of fig (Ficus carica L.) paste for the treatment of loperamide-induced constipation in a rat model. METHODS Animals were divided into one normal control group and four experimental groups (0, 1, 6, and 30 g/kg). Loperamide (2 mg/kg, twice per day) was injected intraperitoneally to induce constipation in the four experimental groups. Fig paste was administered for 4 weeks to assess its anti-constipation effects. RESULTS Fecal pellet number, weight and water content were increased in the fig-treated groups as compared to the control group. Reductions in body weight and increased intestinal transit length were observed in the fig-treated groups. Fecal pellet number was reduced in the distal colons of the fig-treated rats. Exercise and ileum tension increased in the experimental groups as compared to the control group. According to histological analyses, the thickness of the distal colon and areas of crypt epithelial cells that produce mucin were increased in the fig-treated groups in a dose-dependent manner. CONCLUSION Constipation was decreased when fig fruit was fed to rats. Specifically, fecal number, weight, and water content, as well as histological parameters such as thickness and mucin areas in the distal colon were improved. Fig treatment may be a useful therapeutic and preventive strategy for chronic constipation.

Development and validation of an LC-MS/MS method for determination of compound K in human plasma and clinical application

A rapid, sensitive and selective analytical method was developed and validated for the determination of compound K, a major intestinal bacterial metabolite of ginsenosides in human plasma. Liquid-liquid extraction was used for sample preparation and analysis, followed by liquid chromatography tandem spectrometric analysis and an electrospray-ionization interface. Compound K was analyzed on a Phenomenex Luna C18 column (100×2.00 mm, 3 μm) with the mobile phase run isocratically with 10 mM ammonium acetate-methanol-acetonitrile (5:47.5:47.5, v/v/v) at a flow rate of 0.5 mL/min. The method was validated for accuracy (relative error <12.63%), precision (coefficient of variation <9.14%), linearity, and recovery. The assay was linear over the entire range of calibration standards i.e., a concentration range of 1 ng/mL to 1,000 ng/ mL (r2 >0.9968). The recoveries of compound K after liquid-liquid extraction at 1, 2, 400, and 800 ng/mL were 106.00±0.08%, 103.50±0.19%, 111.45±5.21%, and 89.62±34.46% for intra-day and 85.40±0.08%, 94.50±0.09%, 112.50±5.21%, and 95.87±34.46% for inter-day, respectively. The lower limit of quantification of the analytical method of compound K was 1 ng/ mL in human plasma. The developed method was successfully applied to a pharmacokinetic study of compound K after oral administration in ten of healthy human subjects.

Pharmacokinetics of a new orally soluble film formulation of sildenafil administered without water.

OBJECTIVE To compare the pharmacokinetic profiles and to assess bioequivalence of a newly developed orally soluble film formulation of sildenafil, taken without water, with those of a conventional formulation of sildenafil. METHODS This study was conducted in a population of healthy subjects as an open-label, randomized sequence, two-period, two-formulation, single-dose, crossover design. The subjects were randomly assigned to 1 of 2 sequences of the two formulations: an orally soluble film (OSF) of 50 mg sildenafil as the test drug and a film-coated tablet (FCT) of 50 mg sildenafil as the reference drug. Blood samples were collected at intervals from 0 to 24 hours after administration. Plasma concentrations of sildenafil and its active metabolite N-desmethyl sildenafil were analyzed using a liquid chromatography/tandem mass spectrometry method. RESULTS 48 healthy male subjects completed the study. The geometric mean (CV%) for Cmax in the OSF and FCT formulations were 267.21 (4.68%) ng/mL and 285.97 (5.32%) ng/mL, respectively. The geometric mean for AUClast in the OSF and FCT formulations were 664.48 (4.40%) ng x h/mL and 647.96 (4.63%) ng x h/mL, respectively. The geometric mean for AUCinf in the OSF and FCT formulations were 685.65 (4.37%) ng x h/mL and 666.28 (4.60%) ng x h/ mL, respectively. The 90% confidence intervals of the ratios of the geometric means of the Cmax, AUClast, and AUCinf were 0.844 - 1.030, 0.961 - 1.091, and 0.965 - 1.093, respectively. CONCLUSIONS The OSF sildenafil formulation exhibited no significant differences in its pharmacokinetics compared with those of the FCT formulation. Therefore this convenient OSF sildenafil formulation, which can be taken without the need for water or chewing, offers physicians a novel and attractive treatment option for men with erectile dysfunction. *These authors contributed equally to this work.

Pharmacokinetic Comparison Study of a Combination Containing 500 mg of Naproxen and 20 mg of Esomeprazole: A Randomized, Single-dose, 2-way Crossover, Open-label Study in Healthy Korean Men

PURPOSE Nonsteroidal anti-inflammatory drugs have been used for analgesic, anti-inflammatory, and antithrombotic effects, but they carry a risk of major gastrointestinal damage. This risk can be greatly reduced by the coadministration of inhibitors of gastric acid secretion, such as proton pump inhibitors. This study was performed for the subsequent marketing of a combination drug that contained 500 mg of naproxen and 20 mg of esomeprazole in Korea. We evaluated the comparative bioavailability and tolerability of the test and reference formulations in healthy men. METHODS A total of 60 healthy men were enrolled in this single-dose, randomized, open-label, 2-period, 2-sequence, crossover study. During each period, men received a combination of 500 mg of naproxen and 20 mg of esomeprazole for test or reference, and between each period, there was a 1-week washout period. Blood samples were obtained 21 times throughout each period before dosing and 0.17, 0.33, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 8, 10, 12, 24, 48, and 72 hours after oral administration. Plasma concentrations were determined using LC-MS/MS. The pharmacokinetic parameters, including Cmax, AUC0-t, AUC0-∞, and Tmax, were measured, and all treatment-emergent adverse events and their associations with the study medications were recorded throughout the entire study. FINDINGS A total of 59 men completed the study. No significant differences were found in the prevalence of AEs between the 2 formulations. In addition, there were no serious or unexpected AEs during the study. Both formulations had very similar Cmax, AUC, and t½ values, but the Tmax of naproxen appeared earlier in the test formulation than in the reference formulation and that of esomeprazole appeared later in the test formulation than in the reference formulation. IMPLICATIONS This study suggests that the test and reference formulations of a combination of 500 mg of naproxen and 20 mg of esomeprazole are bioequivalent in the extent of absorption and peak concentration. We anticipate that the test formulation will treat those who need relief from pain and inflammation and will decrease the risk of developing gastric ulcers. cris.nih.go.kr identifier: KCT0001117.

Pharmacokinetic properties and bioequivalence of candesartan cilexetil in Korean healthy volunteers.

Candesartan is a long-acting and selective nonpeptide AT1 subtype angiotensin II receptor antagonist. The aim of this study was to compare the pharmacokinetics and to evaluate the bioequivalence of two candesartan cilexetil 16 mg formulations. Forty healthy volunteers were randomly assigned into two groups. After a single dose of 16 mg candesartan cilexetil oral administration, blood samples were collected at specific time intervals from 0–36 h. The plasma concentrations of candesartan cilexetil were determined by LC-MS/MS. The pharmacokinetic parameters such as AUClast, AUCinf and Cmax were calculated and the 90% confidence intervals of the ratio (test/reference) pharmacokinetic parameters were obtained by analysis of variance on logarithmically transformed data. The mean for AUClast in the reference and the test drug were 1530.1 ± 434.6 and 1315.7 ± 368.6 ng·h/mL. The mean for AUCinf in the reference and the test drug were 1670.0 ± 454.5 and 1441.2 ± 397.8 ng·h/mL. The mean value for Cmax in the reference and the test drug was 142.6 ± 41.0 and 134.9 ± 41.4 ng/mL. The 90% confidence intervals for the AUClast, AUCinf and Cmax were in the range of log 0.81–log 0.91, log 0.81–log 0.91 and log 0.88–log1.01, respectively. No adverse events were reported by subjects or found on analysis of vital signs or laboratory tests. This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these health volunteers. Both formulations were safe and well tolerated in 16 mg of candesartan cilexetil hydrochloride.

Method Development of Ellagic Acid as Marker Compound for Standardization of Gochang Bokbunja (Rubus coreanus Miquel) as Functional Ingredient

Method development and validation of ellagic acid for the standardization of Gochang Bokbunja as a functional ingredient and health food were accomplished. A Symmetry (C18, , ) column was used with a gradient elution system of 1% formic acid in water and acetonitrile. This method was validated according to specificity, linearity, accuracy, precision test, and recovery test. Specificity was confirmed with identical retention time, and calibration curves of ellagic acid showed good linear regression ( >0.9996). Relative standard deviations (RSD) of data from the intra- and inter-day experiments were less than 2.28% and 2.84%, except in the low limit of quality control (LLOQ, ) sample. The results of the recovery test were from 89.17% to 97.92% with RSD values from 0.05 to 0.14%. Therefore, we performed analysis of ellagic acid as a marker compound in Gochang Bokbunja extracts. The amount of ellagic acid in Gochang Bukbunja was about (0.192%) in the three times analysis, and RSD was less than 2.36% by the validated method. These results suggest that the developed HPLC method is simple, efficient, and could contribute to the quality control of Gochang Bokbunja extract as a functional ingredient.

An Assessment of the Pharmacokinetics of a Sustained-release Formulation of a Tramadol/Acetaminophen Combination in Healthy Subjects

PURPOSE To provide consistent pain relief and improve convenient sustained release (SR), a fixed-dose combination tramadol/acetaminophen tablet was formulated. This study aimed to evaluate the pharmacokinetic profiles of an SR 75-mg tramadol/650-mg acetaminophen formulation after a single dose compared with an immediate release (IR) 37.5-mg tramadol/325-mg acetaminophen formulation after 2 doses and at steady state and to assess the effect of food on the pharmacokinetic SR formulation profile after a single dose. METHODS Two clinical trials were conducted: (1) an open-label, randomized, 3-period, 3-treatment, crossover study to assess the pharmacokinetic SR (one 75-mg tramadol/650-mg acetaminophen combination tablet) formulation profiles after a single dose and IR (one 37.5-mg tramadol/325-mg acetaminophen combination tablet q6h for 2 doses) formulation profiles after 2 doses and the effect of food intake on healthy male subjects and (2) an open, randomized, 2-period, 2-treatment multiple dose crossover study to evaluate the steady-state pharmacokinetic SR and IR formulation profiles. Safety assessments were performed. FINDINGS Forty-three subjects completed each study protocol. The SR combination tramadol/acetaminophen formulation was clinically and statistically equivalent to the IR combination formulation in the fasting state. When tramadol and acetaminophen tablets were administered with food, the time to peak plasma concentrations and the tramadol/acetaminophen absorption were unaffected. There was no serious adverse event reported. IMPLICATIONS The SR combination tramadol/acetaminophen tablet exhibited similar exposure and absorption rates compared with those of the IR formulation of tramadol, O-desmethyltramadol, and acetaminophen. The SR formulation may be more convenient for patients and has the potential to enhance compliance and pain control. ClinicalTrials.gov identifier: NCT01880125.

Pharmacokinetic properties and bioequivalence of olmesartan medoxomil/hydrochlorothiazide in healthy Korean male subjects.

UNLABELLED Olmesartan medoxomil inhibits the vasoconstrictor effects of angiotensin II. Hydrochlorothiazide (HCTZ) promotes sodium excretion, resulting in a reduction of plasma volume and peripheral resistance. A combination of these agents is known to have a greater effect for the treatment of hypertension than monotherapy with either one of these components. OBJECTIVE To assess bioequivalence between fixed-dose combination of olmesartan medoxomil and hydrochlorothiazide (HCTZ) in healthy Korean subjects. METHODS 40 healthy Korean volunteers were randomized into two groups. After administration of a single dose of investigational products, blood samples were collected before study drug administration (baseline) and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, 24, and 36 hours after study drug administration. The plasma concentrations of olmesartan and HCTZ were measured by LC-MS/MS. The pharmacokinetic parameters were calculated, and the 90% confidence intervals (CIs) of the geometric mean ratio (test/reference) of the parameters were obtained by analysis of variance (ANOVA) on logarithmically transformed data. RESULTS The corresponding 90% CIs for the geometric mean ratio of the test to reference drugs were 0.93 - 1.04, 0.93 - 1.04, and 0.95 - 1.10. For HCTZ treatments, the 90% CIs for the geometric mean ratio of test to reference drugs were 0.95 - 1.03 for AUClast, 0.96 - 1.03 for AUC∞, and 0.89 - 1.04 for Cmax. CONCLUSION This study demonstrated that the test and reference products met the regulatory criteria assuming bioequivalence. Both formulations were safe and well tolerated, and there were no noteworthy differences in the safety profiles of the test and reference drugs.

A Randomized, Double-Blind, Placebo-Controlled Study of the Safety and Efficacy of Olanzapine for the Prevention of Chemotherapy-Induced Nausea and Vomiting (CINV) in Patients Receiving Moderately Emetogenic Chemotherapy: Results of the Korean South West Oncology Group (KSWOG) Study

Purpose Data on the efficacy of olanzapine in patients receiving moderately emetogenic chemotherapy (MEC) are limited. This study aimed to evaluate and compare the efficacy of olanzapine versus placebo in controlling nausea and vomiting in patients receiving MEC. Materials and Methods We conducted a randomized, double-blind, placebo-controlled study to determine whether olanzapine can reduce the frequency of chemotherapy-induced nausea and vomiting (CINV) and improve the quality of life (QOL) in patients receiving palonosetron and dexamethasone as prophylaxis for MEC-induced nausea and vomiting. The primary end point was complete response for the acute phase (0-24 hours after chemotherapy). The secondary end points were complete response for the delayed (24-120 hours) and overall phase (0-120 hours), proportion of significant nausea (visual analogue scale ≥ 25 mm), use ofrescue medications, and effect on QOL. Results Fifty-six patients were randomized to the olanzapine (n=29) and placebo (n=27) groups. Complete response rates were not significantly different between the olanzapine and placebo groups in the acute (96.5% vs. 88.0%, p=0.326), delayed (69.0% vs. 48.0%, p=0.118), and overall phases (69.0% vs. 48.0%, p=0.118). However, the percentage of patients with significant nausea (17.2% vs. 44.0%, p=0.032) and the use of rescue medications (0.03±0.19 vs. 1.88±2.88, p=0.002) were lower in the olanzapine group than in the placebo. Furthermore, the olanzapine group demonstrated better QOL (p=0.015). Conclusion Olanzapine combined with palonosetron and dexamethasone significantly improved QOL and vomiting control among previously untreated patients receiving MEC, although the efficacy was limited to the reduction of the frequency of CINV.

Pharmacokinetic properties of isosorbide-5-mononitrate under fasting and fed conditions in healthy male subjects.

OBJECTIVE This study was performed to compare the pharmacokinetic properties and relative bioavailability of two isosorbide-5-mononitrate (5-ISMN) sustained-release drugs in healthy Korean subjects under fasting and fed conditions. METHODS A total of 60 healthy volunteers (30 each in the fasting and fed arms of the study) were enrolled in the study and were randomized to treatment. After the administration of a single dose of one of the investigational products, blood samples were collected at specific time intervals from 0 to 36 hours. The plasma concentrations of 5-ISMN were measured by LC-MS/MS. The pharmacokinetic parameters were calculated, and the 90% confidence intervals (CIs) of the geometric mean ratio (test/reference) of the parameters were obtained by analysis of variance on logarithmically transformed data. RESULTS The corresponding 90% CIs of AUClast and Cmax for the test/reference geometric mean ratio were 90.75 - 98.44% and 92.28 - 98.33%, respectively, under fasting conditions. In the fed state study, the 90% CIs for the geometric mean ratio of test to reference drugs were 94.79 - 103.33% for AUClast and 99.86 - 108.02% for Cmax. CONCLUSION The test product is equivalent to the reference product in subjects under fasting and fed conditions within the Korean regulatory bioequivalence criteria. Both formulations were safe and well tolerated, and there were no noteworthy differences in the safety profiles between the test and reference drugs.