scholarly journals ANALYTICAL METHOD VALIDATION, PHARMACOKINETICS AND BIOEQUIVALENCE STUDY OF DIMETHYL FUMARATE IN HEALTHY IRANIAN VOLUNTEERS

Author(s):  
GHASEMIAN ELHAM ◽  
SADRAI SIMA ◽  
SHOKRI JAVAD ◽  
SAYADI SHAHRAM

Objective: Pharmacokinetic evaluation of Dimethyl Fumarate (DMF) in the Iranian population wasn’t studied. So, the aim of this research is the validation of the analytical method and evaluation of the pharmacokinetic properties and bioequivalence of the generic form of this drug versus the reference product. Methods: 2 single-dose, test, and reference DMF products were orally administered to 24 healthy volunteers. The washout period was 28 d between the treatments. Monomethyl fumarate as the metabolite of DMF was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the method was validated. Also, the pharmacokinetic parameters were calculated for bioequivalence evaluation. Results: The analytical method was validated and linear over the range of 31.25-4000 ng/ml (R2= 0.997). In addition, the method was precise and accurate in the low, medium, and high concentrations. The results indicated that the 2 products had similar pharmacokinetics. Further, the 90% CI of the mean ratios of the test versus the reference products of the log-transformed area under the concentration-time curve over 10 h (0.99 to 1.02) and peak concentration (0.98 to 1.03) were within the acceptable range of 0.8 to 1.25 and the generic product of DMF could be similar to that of the reference product. Conclusion: The applied analytical method is selective, accurate, precise, and repeatable for the analysis of monomethyl fumarate (MMF) in plasma. Also, the bioequivalence study showed no significant difference between the pharmacokinetic parameters of these 2 products. So, the DMF test product can be claimed to be bioequivalent with the reference product.

1997 ◽  
Vol 41 (5) ◽  
pp. 982-986 ◽  
Author(s):  
T P Kanyok ◽  
A D Killian ◽  
K A Rodvold ◽  
L H Danziger

Aminosidine is an older, broad-spectrum aminoglycoside antibiotic that has been shown to be effective in in vitro and animal models against multiple-drug-resistant tuberculosis and the Mycobacterium avium complex. The objective of this randomized, parallel trial was to characterize the single-dose pharmacokinetics of aminosidine sulfate in healthy subjects (eight males, eight females). Sixteen adults (mean [+/- standard deviation] age, 27.6 +/- 5.6 years) were randomly allocated to receive a single, intramuscular aminosidine sulfate injection at a dose of 12 or 15 mg/kg of body weight. Serial plasma and urine samples were collected over a 24-h period and used to determine aminosidine concentrations by high-performance liquid chromatographic assay. A one-compartment model with first-order input, first-order output, and a lag time (Tlag) and with a weighting factor of 1/y2 best described the data. Compartmental and noncompartmental pharmacokinetic parameters were estimated with the microcomputer program WinNonlin. One subject was not included (15-mg/kg group) because of the lack of sampling time data. On average, subjects attained peak concentrations of 22.4 +/- 3.2 microg/ml at 1.34 +/- 0.45 h. All subjects had plasma aminosidine concentrations below 2 microg/ml at 12 h, and all but two subjects (one in each dosing group) had undetectable plasma aminosidine concentrations at 24 h. The dose-adjusted area under the concentration-time curve from 0 h to infinity of aminosidine was identical for the 12- and 15-mg/kg groups (9.29 +/- 1.5 versus 9.29 +/- 2.2 microg x h/ml per mg/kg; P = 0.998). Similarly, no significant differences (P > 0.05) were observed between dosing groups for peak aminosidine concentration in plasma, time to peak aminosidine concentration in plasma, Tlag, apparent clearance, renal clearance, elimination rate constant, and elimination half-life. A significant difference was observed for the volume of distribution (0.35 versus 0.41 liters/kg; P = 0.037) between the 12 and 15 mg/kg dosing groups. Now that comparable pharmacokinetic profiles between dosing groups have been demonstrated, therapeutic equivalency testing via in vitro pharmacokinetic and pharmacodynamic modelling and randomized clinical trials in humans should be conducted.


Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 243 ◽  
Author(s):  
Yao Yang ◽  
Zhengwei Huang ◽  
Xuan Zhang ◽  
Jinyuan Li ◽  
Ying Huang ◽  
...  

Major depressive disorder (MDD) is one of the main contributors to disability and suicide mortality globally. Paroxetine hydrochloride (PHH) is the most potent antidepressant used for MDD treatment. Due to its reduced side effects PAXIL® CR is a widely-used controlled-release formulation of PHH. However, the complicated double-layer production of PAXIL® CR faces the risk of layer separation. In this study, PHH enteric coating single layer controlled-release tablets (PHH-EC-SLTs) were designed as a simplified substitution of PAXIL® CR through a rational formulation screening. The optimized PHH-EC-SLTs showed similar release behaviors in vitro to PAXIL® CR and the release profiles corresponded to a zero-order release model (R2 = 0.9958). Polymer matrix erosion was the main release mechanism, according to the fitting exponents n > 1 in the Korsmeyer-Pappas model. Crucial pharmacokinetic parameters including peak-reaching time (Tmax), peak concentration (Cmax) and the area under the blood level-time curve (AUC0-48) of PHH-EC-SLTs and PAXIL® CR had no significant difference (p > 0.05) and the relative bioavailability (F = 97.97%) of PHH-EC-SLTs demonstrated their similar pharmacokinetic profiles in vivo. In view of avoiding layer separation risk and simplifying the preparation processing, the self-made PHH-EC-SLTs could be considered as a safe and economic alternative to PAXIL® CR.


Author(s):  
GNANASEKARAN JOHN SELVARAJ ◽  
ARUL BALASUBRAMANIAN ◽  
KOTHAI RAMALINGAM

Objective: The present study was aimed to alter the pharmacokinetic parameters of the drug pentoxifylline using a novel natural mucoadhesive polymer from two different plants, Manilkara zapotta Linn and Ocimum basilicum Linn. Methods: The polymer was isolated and six batches of mucoadhesive tablets of pentoxifylline was formulated with 3 different concentrations of each polymer. The best formulation from each of the polymer was selected and administered to rabbits and the plasma drug concentration was compared with the marketed formulation. The pharmacokinetic parameters such as such as Cmax, tmax, AUC, AUMC, λz, t1/2, and MRT were determined. Results: The plasma drug concentration vs time curve shows the extended-release of pentoxifylline when compared with the conventional marketed formulation. The results show that there is no change in the peak plasma concentration, but the significant difference was observed in t½, which showed approximately 2.5 fold increase from 2.44 to 6.87 h and the AUC showed five-fold increase from 22.40 to 117.19 μg*h/ml, and other pharmacokinetic parameters, when compared with the marketed formulation. Conclusion: The isolated polymer from the plants Manilkara zapotta Linn. and Ocimum basilicum Linn can be used as a carrier for developing mucoadhesive formulations and it alter the pharmacokinetic of pentoxifylline positively.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1666
Author(s):  
Ying Li ◽  
Yin Wu ◽  
Ya-Jing Li ◽  
Lu Meng ◽  
Cong-Yang Ding ◽  
...  

Herein, the effect of silymarin pretreatment on the pharmacokinetics of simvastatin in rats was evaluated. To ensure the accuracy of the results, a rapid and sensitive UPLC–MS/MS method was established for simultaneous quantification of simvastatin (SV) and its active metabolite simvastatin acid (SVA). This method was applied for studying the pharmacokinetic interactions in rats after oral co-administration of silymarin (45 mg/kg) and different concentrations of SV. The major pharmacokinetic parameters, including Cmax, tmax, t1/2, mean residence time (MRT), elimination rate constant (λz) and area under the concentration-time curve (AUC0–12h), were calculated using the non-compartmental model. The results showed that the co-administration of silymarin and SV significantly increased the Cmax and AUC0–12h of SVA compared with SV alone, while there was no significant difference with regards to Tmax and t1/2. However, SV pharmacokinetic parameters were not significantly affected by silymarin pretreatment. Therefore, these changes indicated that drug-drug interactions may occur after co-administration of silymarin and SV.


2014 ◽  
Vol 8 (2) ◽  
pp. 237-240
Author(s):  
Monchana Jullangkoon ◽  
Sutep Jaruratanasirikul ◽  
Nanchanit Aeinlang

Abstract Background: Cefepime, a fourth generation cephalosporin, is a broad spectrum antibiotic effective against both Gram positive and Gram negative bacteria. It is available from several pharmaceutical firms in southeast Asia. We studied bioequivalence of two products. Objective: To assess the bioequivalence of two cefepime formulations: Cefamax 1 g intramuscular (Siam Pharmaceutical, Bangkok, Thailand) as the test formulation and Maxipime 1 g (Bristol-Myers Squibb, Bangkok, Thailand) as the reference formulation. Methods: The study was conducted as an open, randomized, two-period crossover trial with a 1 week washout period in 18 healthy volunteers. Each subject received a single dose of 1 g intramuscular injection of the test or reference formulation. Blood samples were collected via an intravascular catheter at several time points over a 12 h period. Plasma cefepime concentrations were quantified by HPLC with photodiode array detection at 280 nm. The statistical comparisons for pharmacokinetic parameters were made using a paired t test. Results: There was no significant difference in the logarithmically transformed values of Cmax, AUC0-12, and AUC0-∞ between Cefamax and Maxipime using an analysis of variance (ANOVA). The 90% confidence intervals (CIs) of Cmax, AUC0-12, and AUC0-∞ between the two formulations were 91.17-105.78, 90.29-97.63, and 88.89-96.57, respectively. All subjects had good tolerance and no serious adverse events were observed. Conclusion: Cefamax 1 g intramuscular formulation is bioequivalent to Maxipime 1 g intramuscular formulation based on 90% CIs for Cmax, AUC0-12, and AUC0-∞ within 80%-125%.


2003 ◽  
Vol 47 (2) ◽  
pp. 820-823 ◽  
Author(s):  
Jianzhong Liu ◽  
Ki-Fai Fung ◽  
Zhangliu Chen ◽  
Zhenling Zeng ◽  
Jie Zhang

ABSTRACT A comparative in vivo pharmacokinetic study of florfenicol was conducted in 18 crossbred pigs infected with Actinobacillus pleuropneumoniae following intravenous (i.v.), intramuscular (i.m.), or oral (p.o.) administration of a single dose of 20 mg/kg. The disease model was confirmed by clinical signs, X rays, pathohistologic examinations, and organism isolation. Florfenicol concentrations in plasma were determined by a validated high-performance liquid chromatography method with UV detection at a wavelength of 223 nm. Pharmacokinetic parameters were calculated by using the MCPKP software (Research Institute of Traditional Chinese Veterinary Medicine, Lanzhou, China). The disposition of florfenicol after a single i.v. bolus was described by a two-compartment model with values for the half-life at α phase (t 1/2α), the half-life at β phase (t 1/2β), the area under the concentration-time curve (AUC0-∞), and the volume of distribution at steady state (V ss) of 0.37 h, 2.91 h, 64.86 μg · h/ml, and 1.2 liter/kg, respectively. The concentration-time data fitted the one-compartment (after i.m.) and two-compartment (after p.o.) models with first-order absorption. The values for the maximum concentration of drug in serum (C max), t 1/2α, t 1/2β, and bioavailability after i.m. and p.o. dosing were 4.00 and 8.11 μg/ml, 0.12 and 3.91 h, 13.88 and 16.53 h, and 122.7 and 112.9%, respectively, for the two models. The study showed that florfenicol was absorbed quickly and completely, distributed widely, and eliminated slowly in the infected pigs, and there was no statistically significant difference between the pharmacokinetic profiles for the infected and healthy pigs.


2004 ◽  
Vol 48 (6) ◽  
pp. 2061-2068 ◽  
Author(s):  
Alison K. Meagher ◽  
Alan Forrest ◽  
Axel Dalhoff ◽  
Heino Stass ◽  
Jerome J. Schentag

ABSTRACT The pharmacokinetics of an extended-release (XR) formulation of ciprofloxacin has been compared to that of the immediate-release (IR) product in healthy volunteers. The only significant difference in pharmacokinetic parameters between the two formulations was seen in the rate constant of absorption, which was approximately 50% greater with the IR formulation. The geometric mean plasma ciprofloxacin concentrations were applied to an in vitro pharmacokinetic-pharmacodynamic model exposing three different clinical strains of Escherichia coli (MICs, 0.03, 0.5, and 2.0 mg/liter) to 24 h of simulated concentrations in plasma. A novel mathematical model was derived to describe the time course of bacterial CFU, including capacity-limited replication and first-order rate of bacterial clearance, and to model the effects of ciprofloxacin concentrations on these processes. A “mixture model” was employed which allowed as many as three bacterial subpopulations to describe the total bacterial load at any moment. Comparing the two formulations at equivalent daily doses, the rates and extents of bacterial killing were similar with the IR and XR formulations at MICs of 0.03 and 2.0 mg/liter. At an MIC of 0.5 mg/liter, however, the 1,000-mg/day XR formulation showed a moderate advantage in antibacterial effect: the area under the CFU-time curve was 45% higher for the IR regimen; the nadir log CFU and 24-h log CFU values for the IR regimen were 3.75 and 2.49, respectively; and those for XR were 4.54 and 3.13, respectively. The mathematical model explained the differences in bacterial killing rate for two regimens with identical AUC/MIC ratios.


1999 ◽  
Vol 43 (6) ◽  
pp. 1516-1519 ◽  
Author(s):  
Leock Y. Ngo ◽  
Ram Yogev ◽  
Wayne M. Dankner ◽  
Walter T. Hughes ◽  
Sandra Burchett ◽  
...  

ABSTRACT To evaluate if atovaquone (ATQ) interacts pharmacokinetically with azithromycin (AZ) in human immunodeficiency virus-infected children, 10 subjects (ages, 4 to 13 years) were randomized in a crossover study to receive AZ (5 mg/kg/day) alone (ALONE) or AZ (5 mg/kg/day) and ATQ (30 mg/kg/day) simultaneously (SIM) prior to receiving AZ and ATQ staggered by 12 h. Despite a lack of significant difference in the mean AZ pharmacokinetic parameters, the steady-state values of AZ’s area under the concentration-time curve from 0 to 24 h and maximum concentration in serum were consistently lower (n = 7 of 7) for the SIM regimen than they were for the ALONE regimen. A larger study will be required to determine if ATQ affects AZ pharmacokinetics and efficacy in a clinically significant manner.


1998 ◽  
Vol 42 (9) ◽  
pp. 2405-2409 ◽  
Author(s):  
Kenneth Miller ◽  
Arnold Louie ◽  
Aldona L. Baltch ◽  
Raymond P. Smith ◽  
Patrick J. Davis ◽  
...  

ABSTRACT Pentoxifylline has immunomodulatory properties and has been shown to decrease organ damage and improve survival in animals with gram-negative sepsis or endotoxemia. This effect is mediated by a reduction in endotoxin-induced production of tumor necrosis factor alpha (TNF-α) by the host. In earlier studies, we observed an unexpected increase in mortality in mice infected with Candida albicans that were given pentoxifylline even though concentrations of TNF-α in serum were not affected. The current study was designed to determine whether the pharmacokinetics of pentoxifylline and its metabolites were altered in C. albicans-infected mice and, if so, whether these changes could have contributed to the increased mortality. Noninfected mice and mice infected with C. albicans were treated with pentoxifylline (60 mg/kg of body weight) intraperitoneally every 8 h. Serum was collected from animals after one (day 0), four (day 1), or seven (day 2) injections of pentoxifylline or saline (controls). The first dose was administered 6 h after C. albicans infection. Serum was pooled. Concentrations of pentoxifylline and metabolites I, IV, and V were determined by capillary gas chromatography. Renal function and hepatic profiles were assessed. Pharmacokinetic parameters (maximum concentration of pentoxifylline in serum, half-life, and area under the concentration-time curve from 0 h to infinity [AUC0–∞]) for all noninfected mice were similar and did not differ from those for day 0-infected mice. For day 1-infected mice, values of these three pharmacokinetic parameters for pentoxifylline and metabolite I were increased two- to fourfold over values for noninfected and day 0-infected mice. For metabolites IV and V, the AUC0–∞was increased approximately eightfold over control values. In addition, day 1-infected mice demonstrated evidence of renal and hepatic dysfunction. In summary, C. albicans infection produced marked changes in the pharmacokinetics of pentoxifylline and its metabolites in the mice. The high concentrations of pentoxifylline and its metabolites in serum attained in infected mice may have contributed to the increased mortality of mice with systemic candidiasis.


Author(s):  
Parameshwar P ◽  
Y N Rao ◽  
Shobha J C ◽  
Y N Reddy ◽  
V M Reddy

The aim of a  randomized, balanced, two treatment, two-period, two-sequence, single-dose, crossover pilot bioavailability and bioequivalence study conducted in 12 healthy adult male volunteers under fasting conditions was to compare steady state pharmacokinetics of Linezolid 600mg tablets of Dr.Reddy’s Laboratories Ltd, and Zyvox ® (Linezolid) 600mg tablets of Pharmacia & Upjohn Company, USA. The subjects were dosed once during the study and the pre-dose blood samples were collected within 1 hr prior to dosing. The concentrations of Linezolid from the blood samples were quantified by validated HPLC method and pharmacokinetic parameters were computed. 90% Confidence intervals of reference Vs test for Cmax  lower limit 87.23 and upper limit 109.24, AUC0-t lower limit 86.20 and upper limit 109.17, AUCO-α lower limit 85.48 and upper limit 111.54. Analysis of variance (ANOVA) did not show significant difference to these parameters. Based on the results obtained, both the formulations have exhibited the same rate and extent of absorption, indicating switch ability in clinical practice.


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