• Korean Journal of Veterinary Research
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• v.53 no.2
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• pp.77-82
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• 2013

The present study was planned to evaluate the bioequivalence of two commercial formulations of enrofloxacin, which have been marketed as 10% injectable solution after intramuscular administration at a single dose of 2.5 mg/kg body weight to 12 clinically healthy goats The study was carried out on the basis of crossover design. The two formulations were: Baytril as a reference product and Spectrama Vet as a test product. The plasma concentrations of enrofloxacin were measured by high performance liquid chromatography (HPLC) with UV detector. The pharmacokinetics of that data was performed using non-compartmental analysis. The maximum plasma concentration ($C_{max}$), time to reach peak concentration ($T_{max}$), area under concentration-time curve (AUC), elimination half-life ($t_{0.5el}$) were 1.14 and $1.05{\mu}g/mL$, 0.79 and 0.83 h, 5.70 and $5.79{\mu}g.h/mL$, 5.19 and 5.39 h for Baytril and Spectrama Vet, respectively. The 90% confidence interval for the mean ratio of $T_{max}$, $C_{max}$ and AUC were 94.72-116.2, 87.88-97.16 and 86.44-118.72%, respectively. These values falls within the European Medicines Agency bioequivalence acceptance range of 80-125% for both $T_{max}$ and AUC and between 75-133% for $C_{max}$. In conclusion, Spectrama-Vet is bioequivalent to Baytril and both products can be used as interchangeable drug in veterinary medicine practice.

• Journal of Pharmaceutical Investigation
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• v.29 no.4
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• pp.361-365
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• 1999

The bioequivalence of 'Bearcef tablet' (Daewoong Pharmaceutical Co.), containing 250 mg cefuroxime (as cefuroxime axetil), in reference to 'Zinnat tablet' (GlaxoWellcome Korea Co.) was evaluated in 16 normal volunteers $(age\; 21{\sim}29\;yrs)$ following the oral administration. After one tablet was administered, blood was taken at predetermined time intervals and the concentration of the drug in plasma was quantitated with an HPLC method. AUC, $C_{max}$ and $T_{max}$ were calculated and statistically analyzed for the bioequivalence of the two products. The results showed that the differences in AUC, $C_{max}$ and $T_{max}$ between two products were 6.92%,3.49% and 5.26%, respectively. The powers for AUC, $C_{max}$ and $T_{max}$ were >90%, >90% and 89.0%, respectively. Confiderice intervals for these parameters were all within ${\pm}20%$. Judging based on the above results, 'Bearcef tablet' is regarded to be bioequivalent to 'Zinnat tablet'.

• YAKHAK HOEJI
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• v.33 no.4
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• pp.229-236
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• 1989

Even though two different preparations are chemically equivalent, the variance of bioavailability differenciates the clinical effect of preparations, so that the preparations need to be evaluated by comparing bioavailability in vivo as well as chemical equivalence. In this study, bioequivalence tests of commercially available isoniazid tablets A, B, C and D (standard) were performed to give some guidelines to bioequivalence test. The bioavailability parameters obtained by drug administeration were statistically analyzed. Statistical evaluation of the data involved an analysis of variance for a cross over design. Cross over design was employed with 8 healthy volunteers. The results were within 20% difference of mean value in the AUC, Cmax, Tmax and amount of urinary excretion (Au) between standard and isoniazid tablets. The results of ANOVA showed no significant differences for 'group or sequence', but almost not for 'between subjects'. The tablet. A, B and D were within 20 min, but tablet C was within 50 min. Tablet A was biologically equivalent in the Au. tablet B biologically equivalent in the Au and AUC. Tablet C was biologically equivalent in the Au. The relationship between the dissolution rate and Au was significant.

• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.277-282
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• 2008

The purpose of the present study was to evaluate the bioequivalence of two topiramate tablets, Topamax tablet (Janssen Korea. Co., Ltd., Seoul, Korea, reference drug) and Topamin tablet (Myungmoon Pharm. Co., Ltd., Seoul, Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male Korean volunteers received one tablet at the dose of 100 mg topiramate in a $2{\times}2$ crossover study. There were two-weeks washout period between the doses. Plasma concentrations of topiramate were monitored by an LC-MS/MS for over a period of 96 hr after administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 96 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance (ANOVA) was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. The 90% confidence intervals of the $AUC_t$, ratio and the $C_{max}$ ratio for Topamin/Topamax were $\log0.88{\sim}\log1.02$ and $\log0.87{\sim}\log1.03$, respectively. These values were within the acceptable bioequivalence intervals of $\log0.80{\sim}\log1.25$. Taken together, our study demonstrated the bioequivalence of Topamax and Topamin with respect to the rate and extent of absorption.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.47-55
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• 2012

The newly revised bioequivalence guideline of Korea allows the add-on test since July 1, 2008 when the initial bioequivalence trial fails to show the equivalence of two drugs. The statistical model of the add-on test and its two stage testing procedures are discussed. Some statistical points of consistency test in the add-on test are considered and the issue on the sample size of add-on test is discussed. Some reasonable alternative like Japan's guideline for bioequivalence studies is recommended to secure the proper use of an add-on study through some simulation studies.

• Korean Journal of Clinical Pharmacy
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• v.14 no.2
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• pp.85-90
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• 2004

Bisoprolol, one of the $\beta_1-adrenorecepter$ antagonist, has been used for the treatment of mild to moderate essential hypertension anti stable angina pectoris. The oral bloavailability of bisoprolo1 is high $(90\%)$ and the drug has a long elimination half-life, $9{\sim}12\;hr$, which allows once-daily administration. The bioequivalence of two bisoprolol preparations was evaluated according to the guidelines of Korea Food & Drug Administration (KFDA). The test product was Concor $tablet^{(R)}$ made by Newgenpharm and the reference product was Monocor $tablet^{(R)}$ made by Wyeth Korea. Twenty healthy male subjects, 23.8 (21-30) years old and 03.8(52-92) kg, were randomly divided into two groups and a randomized $2\times2$ cross-over study was employed. After two tablets containing 10 mg bisoprolol hemifumarate were orally administered, blood was taken at predetermined time intervals and the concentration of bisoprolol in plasma was determined using an HPLC method with fluorescence detector. Two pharmacokinetic parameters, $AUC_t\;and\;C_{max}$ were calculated and analyzed statistical]y for the evaluation of bioequivalence of the two products. Analysis of variance was carried out using logarithmically transformed parameter values. The $90\%$ confidence intervals of $AUC_t\;and\;C_{max}$ were log $0.95{\sim}1og\;1.04\;and\;1og\;0.96{\sim}1og\;1.07,\;respectively.$ These values were within the acceptable bioequivalence intervals of log $0.8{\sim}log\;1.23$. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating that Concor tablet is bioequivalent to Monocor tablet.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.287-293
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, Amaryl tablet (Handok & Aventis Korea, reference drug) and Mepiril tablet (Myungmoon Pharm. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (glibenclamide) to human plasma, plasma samples were extracted using 1mL of methyl tertiary butyl ether. Compounds extracted were analyzed by reverse-phase HPLC with multiple reaction monitoring (MRM) mode analyte detection. This method for determination glimepiride proved accurate and reproducible, with a limit of quantitation of 2 ng/mL in human plasma. Twenty-four healthy male Korean volunteers received each medicine at the glimepiride dose of 2 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of glimepiride were monitored by a LC-MS/MS for over a period of 12 hr after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Amaryl/Mepiril were log 0.9583-log 1.1357 and log 1.0570-log 1.2376, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Taken together, our study demonstrated the bioequivalence of Amaryl and Mepiril with respect to the rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.57-62
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• 2007

The purpose of the present study was to evaluate the bioequivalence of two donepezil tablets, $Aricept^{TM}$ tablet (Dae Woong Pharm. Co., Ltd., Korea, reference drug) and $Donpezil^{TM}$ tablet (Dong Wha Pharm. Ind. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male Korean volunteers received one tablet containing donepezil hydorchloride 10 mg in a $2{\times}2$ crossover study. There was a three-week washout period between the doses. Plasma concentrations of donepezil were monitored by an LC-MS/MS far over a period of 240 hr after the administration. $AUC_t$, (the area under the plasma concentration-time curve from time zero to 240 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$)were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$, No significant sequence effects were found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ and $C_{max}$ were log 0.95${\sim}$log 1.03 and log 0.94${\sim}$log 1.08, respectively. These values were within the acceptable bioequivalence intervals of log 0.80${\sim}$log 1.25. Taken together, our study demonstrated the bioequivalence of $Aricept^{TM}$ and $Donpezil^{TM}$ with respect to the rate and extent of absorption.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.525-533
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• 2006

The aim of this study was to evaluate the bioequivalence of risperidone in healthy male subjects representing different CYP2D6 genotypes with respect to risperidone, 9-hydroxyrisperidone (9-OH-risperidone), and active moiety. A total of 506 Korean subjects were genotyped for $CYP2D6^*10$ by means of allele-specific polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Based on the genotype analysis, 24 subjects, 7 homozygous for $CYP2D6^*1$ for $^*10$, and 7 heterozygous for $^*10$, were recruited and received a single oral dose of 2 mg risperidone tablet in this study. Serum concentrations of risperidone and 9-OH-risperidone up to 48 h were simultaneously determined. There were no significant differences of the active moiety, risperidone, and 9-OH-risperidone between the two preparations in AUC_{0-{\propto}}$ and $C_{max}$. The 90% confidence intervals (Cls) for the ratio of means of the log-trans-formed AUC_{0-{\propto}}$ and $C_{max}$ for the active moiety, risperidone, and 9-OH-risperidone were all within the bioequivalence acceptance criteria of 0.80-1.25. The $CYP2D6^*10$ allele particularly was associated with higher serum concentrations of risperidone and the risperidone/9-OH-risperidone ratio compared with the $CYP2D6^*1$ allele. The results demonstrate that the two preparations of risperidone are bioequivalent and it can be assumed that they are therapeutically equivalent and exchangeable in clinical practice. Furthermore, the pharmacokinetic parameters of risperidone and the risperidone/9-OH-risperidone ratio are highly dependent on the CYP2D6 genotypes.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.311-317
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• 2004

A bioequivalence study of $Gomcillin^{TM}$ capsules (DAEWOONG Pharmaceutical Co., Korea) to $Famoxin^{TM}$ capsules (Dong Wha Pharm. Ind. Co., Korea) was conducted according to the guideline of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the amoxicillin dose of 500 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of amoxicillin were monitored by a high-performance liquid chromatography for over a period of 8 hours after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 8 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Gomcillin^{TM}/Famoxin^{TM}$ were $log0.91\;{\sim}\;log1.03$ and $;log0.93\;{\sim}\;log1.10$, respectively. These values were within the acceptable bioequivalence intervals of $log0.80\;{\sim}\;log1.25$. Thus, our study demonstrated the bioequivalence of $Gomcillin^{TM}$ and $Famoxin^{TM}$ with respect to the rate and extent of absorption.