• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.315.1-315.1
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• 2003

After beginning the new medical system separating the prescription from the drug dispensary, the demand of bioequivalence test significantly increases to show the equivalence between the test and reference drugs as a result of amendment of the pharmaceutical affairs law which allows a generic substitution. Accordingly the standard protocols provided by the government are required for reducing the period andthe cost to perform the bioequivalence study. (omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2006년도 추계학술대회
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• pp.80-86
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• 2006

Bioequivalence is a term in pharmacokinetics used to access the expected in vivo biological equivalence of two proprietary preparations of a drug. Bioequivalence studies are usually performed for generic drugs. Two pharmaceutical products are bioequivalent if they are pharmaceutically equivalent and their bioavailabilioes after administration in the same molar dose are similar. Bioequivalence is usually accessed by single dose in vivo studies in healthy volunteers and the reference product is usually the innovator product that is marketed. Regulatory definition of bioequivalence is based on the statistical analysis of thebioavailability of the reference and test product. In general, two products are evaluated as bioequivalent if the 90% confidence interval of the relative mean Cmaxand AUC of the test to reference product are within 80.00% to 125.00% in the fasting state. Key process in bioequivalence study is development and validation of bioanalytical method, determination of the drug concentration in the biosamples (usually plasma or serum) obtained from volunteers, calculation of the pharmacokinetic parameters and statistical analysis of the pharmacokinetic parameters. Although current guidelines and regulations do not require the bioequivalence studies to be done under good laboratory practice (CLP), the issues to perform the bioequivalence studies under GLP environment is emerged both from the regulatory and industry side. GLP perspectives of bioequivalence studiesare needed to be discussed in respect to achieve quality assurance in bioequivalence studies.

• Journal of Pharmaceutical Investigation
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• 제39권3호
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• pp.217-219
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• 2009

There are several approaches to calculate a sample size for bioequivalence test. Among these approaches, sample sizes determination based on Schuirmann's two one-sided tests procedures has been used most popularly in case of 2${\times}$2 bioequivalence study. Here we proposed simple sample size table for conventional 2${\times}$2 bioequivalence test based on Schuirmann's two one-sided tests in accordance with Korean Guidelines for Bioequivalence Test. This table will allow researchers with a little statistical background to calculate the sample size for bioequivalence with easy process.

• Journal of the Korean Data and Information Science Society
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• 제17권1호
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• pp.245-257
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• 2006

A modified Anderson and Hauck(1983) test for analyzing a two-sequence two-period crossover design in bioequivalence trials is proposed when some observations at the second period are missing. It is based on the maximum likelihood estimators of average bioequivalence model and designed for handling missing at random(MAR) situation. The performance of the proposed test is compared to other tests using Monte Carlo simulations.

• 한국임상약학회지
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• 제19권1호
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• pp.50-60
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• 2009

Highly variable drugs (within-subject variability greater than 30%) have been difficult to meet current regulatory acceptance criteria using a reasonable number of study subjects. In this study, we reviewed previous studies presenting alternative approaches for bioequivalence evaluation of highly variable drugs, and focused on an approach for widening the bioequivalence acceptance limits using within-subject variability. We discussed the suggested five solutions for highly variable drug including the deletion of $C_{max}$ of the bioequivalence criteria, direct expansion of bioequivalence limit, multiple dose studies in steady state, bioequivalence assessment on the metabolite, add-on study, and widening the bioequivalence acceptance limits based on reference variability. The methods for widening of bioequivalence limits based on reference variability are scaled average bioequivalence containing within-subject variability on reference drug (${\sigma}_{WR}$), population bioequivalence derived from total variability on reference drug (${\sigma}_{TR}$) and test drug (${\sigma}_{TT}$), and individual bioequivalence derived from subject by formulation interaction variability (${\sigma}_D$) and within subject variability on reference drug (${\sigma}_{WR}$) and test drug (${\sigma}_{TR}$). To apply these methods, the switching variability (${\sigma}_0$) will have to be set by the regulatory authorities. The proposals of bioequivalence evaluation approach for the highly variable in Korea are presented for both of new drug and reevaluation drug.

• 약학회지
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• 제54권4호
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• pp.295-299
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• 2010

The aim of this study was to develop and validate for determination of alibendol in human plasma by HPLC method. After precipitation of 500 ${\mu}l$ plasma samples by 50% methanol 50 ${\mu}l$ and 60% perchloric acid 30 ${\mu}l$ and the supernatant 50 ${\mu}l$ was injected into HPLC. The assay was performed isocratically using 10 mM potassium phosphate (pH 3.0) and acetonitrile (80 : 20, v/v) as mobile phase. The $C_{18}$ column (particle size $3.5{\mu}m$, $4.6{\times}50$ mm, Zorbax Eclipse) was used as a solid phase. The mobile phase was delivered at a flow-rate of 1.7 ml/min, detection was by ultraviolet absorption at 232 nm and concentrations were calculated on the basis of peak areas. In these conditions, alibendol can be separated from ethylparaben, the internal standard, and endogenous substances. The retention times of alibendol and ethylparaben were just about 2.6 and 3.5 minutes, respectively. This rapid HPLC method was validated by examining the precision and accuracy for inter- and intra-day analysis. The standard curve was linear ($R^2$=1.0000) over the concentration range of 0.05~20 ${\mu}g$/ml. The inter-day relative standard deviation (R.S.D.) and accuracy were 0.2~12.2% and 94.4~101.2% (82.7% at the lower limit of quatitation). The intra-day R.S.D. and accuracy were 0.1~11.8% and 98.8~102.5%, respectively. The method was successfully applied to the determination of alibendol in plasma for a pharmacokinetic study.

• Journal of Pharmaceutical Investigation
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• 제19권4호
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• pp.191-194
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• 1989

Bioequivalence test of $Asthcontin^{\circledR}$ tablet, a commercial slow-release theophylline (TP) dosage form, was performed using $Slo-bid^{\circledR}$ capsule as the reference. Since it has been confirmed that the saliva concentration of TP is closely correlated with the plasma concentration in man, the area under the saliva concentration-time curve was used as a bioavailability parameter. The statistical analysis showed that the two dosage forms are equivalent in bioavailability estimating from the saliva concentration. The results supported that the use of soliva as a test sample provides simple and easy techniques for bioequivalence tests of TP-containing dosage forms.

• Archives of Pharmacal Research
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• 제13권2호
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• pp.180-186
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• 1990

A bioequivalence study of ranitidine tablets was conducted according to the Korean Guidine for the Bioequivalence Test using twelve healthy male subjects. The plasma concentration-timecurves of ranitidine from the test and reference tablets showed profound multiple peak phenomenon in each subject as reported earlier. However, the area under the plasma concentration-time curve (AUC) and the maximum ploasma concentration at the first peak ($C_{max1}$) of the two preparations was proven to be equal when analyzed satistically according to the criteria of the guidline;i. e., statistical power (1-$\beta$)was calculated to be over 0.8 under the condition of $\alpha$ = 5% and $\Delta$(minimum detectable difference) = 20%, and the confidence interval of the difference in AUC at 95% confidence level was in the range of $\pm$ 20%, which statisfied the criteria of bioequivalence. Equivalence of the peak concentration of ranitidine at the second peak ($C_{max2}$), and the time to reach the first ($T_{max1}$) and second verify the bioequivalence of $c_{max2}$ , $T_{max1}$ and $T_{max2}$ between the two tablets. However, we conclude that the test and reference tablets are bioequivalent taking the therapeutic characteristics of the ranitidine preparations into consideration.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.47-55
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• 2012

식품의약품안전청에서는 제제간의 생물학적 동등성의 입증이 실패했을 경우 추가시험을 허용하는 시험 기준을 2008년 7월부터 시행하고 있다. 생물학적 동등성 시험의 추가시험규정은 원시험에서의 동등성 평가가 불충분한 시험 예수 때문에 실패했을 때 별도의 재시험 시험계획서를 제출하지 않고 피험자수를 증가시켜 다시 시험하여 제제간의 동등성을 평가할 수 있는 근거를 마련한 점에 긍정적이다. 하지만 최근 추가시험의 규정에 따라 군당 12명 이상의 피험자를 사용했을 경우 오히려 추가시험의 일관성 검정 규정을 만족하지 못하여 추가시험이 실패되는 경우가 자주 발생하고 있어 추가시험규정에 대한 불만이 고조되고 있다. 본 연구에서는 이러한 상황이 발생되는 통계적 원인을 살펴보고 현 기준을 일본 규정처럼 조금 더 일반화하게 되면 추가시험을 더 폭넓게 사용할 수 있는 것을 제안하고자 한다.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 춘계 학술발표회 논문집
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• pp.67-72
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• 2002

A Bayesian testing procedure is proposed for assessment of bioequivalence in both mean and variance which ensures population bioequivalence under normality assumption. We derive the joint posterior distribution of the means and variances in a standard 2 ${\times}$ 2 crossover experimental design and propose a Bayesian testing procedure for bioequivalence based on a Markov chain Monte Carlo methods. The proposed method is applied to a real data set.