• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.7 s.337
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• pp.35-40
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• 2005

This paper proposes a fractional-N phase-locked loop (PLL) frequency synthesizer using the 3rd order ${\Delta}{\sum}$ modulator for 900MHz medium speed wireless link. The LC voltage-controlled oscillator (VCO) is used for the good phase noise property. To reduce the lock-in time, a charge pump has been developed to control the pumping current according to the frequency steps and the reference frequency is increased up to 3MHz. A 36/37 fractional-N divider is used to increase the reference frequency of the phase frequency detector (PFD) and to reduce the minimum frequency step simultaneously. A 3rd order ${\Delta}{\sum}$ modulator has been developed to reduce the fractional spur VCO, Divider by 8 Prescaler, PFD and Charge pump have been developed with 0.25um CMOS, and the fractional-N divider and the third order ${\Delta}{\sum}$ modulator have been designed with the VHDL code, and they are implemented through the FPGA board of the Xilinx Spartan2E. The measured results show that the output power of the PLL is about -lldBm and the phase noise is -77.75dBc/Hz at 100kHz offset frequency. The minimum frequency step and the maximum lock-in time are 10kHz and around 800us for the maximum frequency change of 10MHz, respectively.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.197-203
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• 2007

A bioequivalence study of $Dilast^{TM}$ Capsule (Chong Kun Dang Pharma. Co., Ltd.) to $Ketas^{(R)}$ Capsule (Han Dok Pharma. Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty eight healthy male Korean volunteers received each medicine at the ibudilast dose of 20 mg in a $2{\times}2$ crossover study. There was one week wash-out period between the doses. Plasma concentrations of ibudilast were monitored by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for over a period of 36 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 36 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 $Dilast^{TM}$ $Capsule/Ketas^{(R)}$ Capsule were $log0.93{\sim}log1.06$ and $log0.93{\sim}log1.11$, respectively. These values were within the acceptable bioequivalence intervals of $log0.80{\sim}log1.25$. Thus, our study demonstrated the bioequivalence of $Dilast^{TM}$ Capsule and $Ketas^{(R)}$ Capsule with respect to the rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.413-419
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• 2006

In this study, the main purpose was to evaluate the bioequivalence of two thioctic acid tablests, Thioctacid HR tablet(Bukwang Pharm. Co., Ltd.) and Daewon thioctic acid HR tablet 600 mg(Daewon Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration(KFDA). Twenty-four, healthy Korean volunteers were divided into two groups, randomized and treated by $2{\times}2$ crossover study. After the administration of one thioctic acid tablet containing 600 mg thioctic acid, blood samples were taken until 8 hr after the oral administration. LC-MS/MS was applied to determination of thioctic acid, and we calculated the $AUC_t,\;C_{max},\;T_{max}$ from the plasma concentration-time data. Analysis of variance(ANOVA) 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 Daewon thioctic acid tablet 600 mg/Thioctacid HR were log 0.9877$\sim$log 1.1938 and log 0.8169$\sim$log 1.2237, respectively. These values were within the acceptable bioequivalence intervals of log 0.80$\sim$log 1.25, recommended by KFDA. In all of these results we concluded that Daewon thioctic acid tablet 600 mg was bioequivalent to Thioctacid HR tablet, in terms of rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.36 no.2
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• pp.131-136
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• 2006

The purpose of the present study was to evaluate the bioequivalence of two losartan tablets, $Cozaar^{TM}$ tablet (MSD Korea. Co., Ltd., Seoul, Korea, reference drug) and $Losartan^{TM}$ tablet (DaeWon Pharm. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male Korean volunteers received two tablets at the losartan kalium dose of 100 mg in a $2\;{\time}\;2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of losartan were monitored by an 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 $Cozaar^{TM}/Losartan^{TM}$ were $log\;0.97{\sim}log\;1.12\;and\;log\;0.93{\sim}log\;1.23$, 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 $Cozaar^{TM}$ and $Losartan^TM$ with respect to the rate and extent of absorption.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.8-15
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• 2002

We optimally designed the VCO(voltage-controlled oscillator) with spiral inductor using the MOSIS HP 0.5${\mu}{\textrm}{m}$ CMOS process. With the developed SPICE model of spiral inductor, the quality factor of spiral inductor was maximized at the operating frequency by varying the layout parameters, e.g., metal width, number of turns, radius, space of the metal lines. For the operation frequency of 2㎓, the inductance of about 3nH, and the MOSIS HP 0.5 CMOS process with the metal thickness of 0.8${\mu}{\textrm}{m}$, oxide thickness of 3${\mu}{\textrm}{m}$, the optimal width of metal lines is about 20${\mu}{\textrm}{m}$ for the maximum Quality factor. With the optimized spiral inductor, the VCO with LC tuning tank was designed, fabricated and measured. The measurements were peformed on-wafer using the HP8593E spectrum analyzer. The oscillation frequency was about 1.610Hz, the frequency variation of 250MHz(15%) with control voltage of 0V - 2V, and the phase noise of -108.4㏈c(@600KHz) from output spectrum.

• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.59-65
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• 2006

The purpose of this study was to evaluate the bioequivalence of two amlodipine maleate tablets, SKAD tablet (SK Pharma. Co., Ltd., Seoul, Korea, reference drug) and A-PINE tablet (Daewon Pharm. Co., Ltd., Seoul, Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male volunteers, $22.79\;{\pm}\;1.86$ years in age and $70.08\;{\pm}\;8.68$ kg in body weight, were divided into two groups and a randomized $2\;{\time}\;2$ crossover study was employed. After a tablet containing 6.42 mg of amlodipine maleate was orally administrated, blood was taken at predetermined time intervals over a period of 144 hr and concentrations of amlodipine in plasma were monitored using LC-MS/MS. Pharmacokinetic parameters such as $AUC_t$ (the area under the plasma concentration-time curve from time zero to 144 hr), $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were calculated and analysis of variance (ANOVA) test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$, and untransformed $T_{max}$. 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 A-PINE/SKAD were $log\;0.9429{\sim}log \;1.1476$ and $log\;0.9l46{\sim}log\;1.1488$, respectively. Since these values were within the acceptable bioequivalence intervals of $log\;0.80{\sim}log\;1.25$, recommended by KFDA, it was concluded that A-PINE tablet was bioequivalent to SKAD tablet, in terms of both rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.315-321
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• 2007

The purpose of the present study was to evaluate the bioequivalence of two lercanidipine hydrochloride tablets, Zanidip tablet (LG Life Sciences Ltd., Korea, reference drug) and Samchundang Lercanidipine tablet 10 mg (Sam Chun Dang Pharm. Co. Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (amlodipine maleate) to human serum, serum samples were extracted using hexan-isoamyl alcohol (100:1, v/v). Compounds were analyzed by liquid chromatography/tandem mass spectrometry. This method showed linear response over the concentration range of 0.05-20 ng/mL with correlation coefficient of 0.9999. The lower limit of quantitation using 0.5 mL of serum was 0.05 ng/mL which was sensitive enough for pharmacokinetic studies. Thirty healthy male Korean volunteers received each medicine at the lercanidipine hydrochloride dose of 20 mg in a $2\;{\times}\;2$ crossover study. There was a one-week washout period between the doses. Serum concentrations of lercanidipine were monitored by an LC/MS/MS fer over a period of 24 hr after the administration. $AUC_t$ (the area under the serum concentration-time curve from time 0 to 24 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (the maximum serum drug concentration) and $T_{max}$ (the time to reach $C_{max}$) were compiled from the serum 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 Samchundang Lercanidipine/Zanidip were log 0.9505-log 1.2258 and log 0.9987-log 1.2013, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Samchundang Lercanidipine tablet 10 mg and Zanidip tablet are bioequivalent.

• Journal of Pharmaceutical Investigation
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• v.40 no.2
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• pp.125-131
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• 2010

A bioequivalence study of LANIDIEM$^{(R)}$ tablet 4 mg (Samil. Co., Ltd.) to Vaxar$^{(R)}$ tablet 4 mg (GlaxoSmithKline Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Forty healthy male Korean volunteers were enrolled in the study and thirty six volunteers completed the study according to the protocol. Thirty six volunteers received each medicine at the lacidipine dose of 4 mg in a $2{\times}2$ crossover study. There was one week wash-out period between the doses. Plasma concentrations of lacidipine were monitored by a high performance liquid chromatography - tandem mass spectrometry (LC-MS/MS) for over a period of 24 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 24 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 LANIDIEM$^{(R)}$/Vaxar$^{(R)}$ were log 0.8102~log 1.0417 and log 0.8493~log 1.1439, respectively. These values were within the acceptable bioequivalence intervals of log 0.80~log 1.25. Thus, our study demonstrated the bioequivalence of LANIDIEM$^{(R)}$ tablet 4 mg and Vaxar$^{(R)}$ tablet 4 mg with respect to the rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.40 no.2
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• pp.109-115
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• 2010

The purpose of the present study was to evaluate the bioequivalence of two choline alphoscerate soft capsules, Gliatilin soft capsule (Daewoong Pharmaceuticals Co., Ltd.) and Cholicerin soft capsule (Sam Chun Dang Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Serum concentrations of choline after oral administration of choline alphoscerate were determined using a validated LC/MS/MS method. This method showed linear response over the concentration range of 0.5-20 ${\mu}g$/mL with correlation coefficient of 0.9999. The lower limit of quantitation using 100 ${\mu}L$ of serum was 0.5 ${\mu}g$/mL which was sensitive enough for pharmacokinetic studies. Thirty six healthy male Korean volunteers received each medicine at the choline alphoscerate dose of 1200 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Blood samples were taken at predetermined time intervals up to 8 hr. $AUC_t$ (the area under the serum concentration-time curve from time 0 to 8 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (the maximum serum drug concentration) and $T_{max}$ (the time to reach $C_{max}$) were compiled from the serum 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 Cholicerin/Gliatilin were log0.9998-log1.1172 and log0.9938-1.0944, respectively. These values were within the acceptable bioequivalence intervals of log0.80-log1.25. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Cholicerin soft capsule and Gliatilin soft capsule are bioequivalent.

• Journal of Pharmaceutical Investigation
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• v.38 no.2
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• pp.135-142
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• 2008

The present study describes the evaluation of the bioequivalence of two atorvastatin tablets, Lipitor $Tablet^{(R)}$ (Pfizer, reference drug) and Atorva $Tablet^{(R)}$ (Yuhan, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Forty-nine healthy male Korean volunteers received each medicine at the atorvastatin dose of 40 mg in a $2{\times}2$ crossover study with a two weeks washout interval. After drug administration, serial blood samples were collected at a specific time interval from 0-48 hours. The plasma atorvastatin concentrations were monitored by an high performance liquid chromatography -tandem mass spectrometer (LC-MS/MS) employing electrospray ionization technique and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.5 min and calibration curves were linear over the concentration range of 0.1-100 ng/mL for atorvastatin. The method was validated for selectivity, sensitivity, linearity, accuracy and precision. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 48hr) was calculated by the linear log trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were complied trom 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 Atorva $Tablet^{(R)}$ / Lipitor $Tablet^{(R)}$ were ${\log}\;0.9413{\sim}{\log}\;1.0179$ and ${\log}\;0.831{\sim}{\log}\;1.0569$, respectively. These values were within the acceptable bioequivalence intervals of ${\log}\;0.8{\sim}{\log}\;1.25$. Based on these statistical considerations, it was concluded that the test drug, Atorva $Tablet^{(R)}$ was bioequivalent to the reference drug, Lipitor $Tablet^{(R)}$.