• Journal of Pharmaceutical Investigation
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• v.13 no.2
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• pp.59-65
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• 1983

A convenient high performance liquid chromatographic method for the quantitative determination and content uniformity of prednisolone in tablets is described. The prednisolone was chromatographed using a ${\mu}-Bondapak\;C_{18}$ column and the eluent 70% MeOH at a flow rate 1. 0ml/min. Diethylstilbestrol was used as an internal standard. The UV detector response at 254nm was linear over a range of $10{\sim}60{\mu}g/ml$ under conditions of the analysis. Reproducibility studies gave relative standard deviations of $0.3{\sim}0.5%$.

• YAKHAK HOEJI
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• v.44 no.5
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• pp.424-431
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• 2000

A biopharmaceutics drug classification system for correlation between in vitro dissolution and in vivo bioavailability is proposed based on recognizing that drug dissolution and gastrointestinal permeability are the fundamental parameters controlling the rate and extent of drug absorption. The objective of this study was to assess whether in vitro dissolution profiles of immediate-release beta-blocker tablets can be correlated with intestinal membrane permeability and/or in vivo bioavailability In vitro dissolution of the beta-blocker tablets was examined using KP VII Apparatus II methods at various pH. Intestinal membrane permeability was determined in vitro using the diffusion chamber method. Bioavailablity parameters were cited from literatures. The dissolution profiles did not accurately represent the in vivo bioavailablity However there were good correlations between intestinal membrane permeability and log P (noctanol/buffer). The correlations obtained in this study indicated that in vitro diffusion chamber method could be used to predict intestinal absorption in vivo.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.279.1-279.1
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• 2003

NIR reflectance spectroscopy, using a fiber-optic probe was used to determine rapidly and non-destructively the content of ambroxol in intact ambroxol 30 mg (nominal content 12.5％ m/m ambroxol) tablets by collecting NIR spectra in range 1100 - 1750 nm and using PLSR calibration method. The tablets (10.3 - 15.9％ m/m ambroxol, i.e., 82 - 127％ of the nominal label content) were used 7 calibration set and 5 validation set. (omitted)

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.379-381
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• 1990

The effect of calcium gluconate on estrogen (estradiol) serum level as well as follicle stimulating hormone level was studied. Our results revealed that oral administration of calcium gluconate (100 mg/kg body wight) to adult non-pregnant female rabbits caused a significant increase of serum levels of estradiol and follicle stimulating hormone. On the other hand, oral contraceptive (Norminest tablets) decreased significantly follicle stimulating hormone serum level, while combined administration of calcium gluconate and oral contraceptive caused significant increase of serum level of follicle stimulating hormone compared with control values. Also, concurrent administration of calcium gluconate and Norminest tablet increased significantly the rate of conception compared with group recieved Norminest tablets only. These results indicated that combined administration of calcium and oral contraceptives must be cautiously.

• Korean Journal of Clinical Pharmacy
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• v.7 no.2
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• pp.73-80
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• 1997

The bioequivalence of two loxoprofen tablets between the $Loxonin^{TM}$ (Dong Hwa Pharmaceutical Co., Ltd.) and the $Lokpen^{TM}$ (Dong Il Pharmaceutical Co., Ltd.) was evaluated. 12 normal male volunteers (age $21\sim27$ years old) were divided into two groups and a randomized cross-over study was employed. After one tablet containing 60 mg of loxoprofen sodium anhydrous was orally administered, blood was taken at predetermined time intervals and the concentration of loxoprofen in serum was determined with an HPLC method using UV/VIS detector. The pharmacokinetic parameters ($C_{max},\;T_{max}$, and $AUC_t$) were calculated and ANOVA was utilized for the statistical analysis of parameters. The results showed that the differences in $C_{max},\;T_{max}$, and $AUC_t$ between two tablets were $1.13\%,\;0\%,\;and\;0.69\%$, respectively The powers (1-${\beta}$) for $C_{max},\;T_{max}$, and $AUC_t$ were $84.88\%,\;88.61\%,\;and\;84.81\%$, respectively Detectable differences ($\delta$) and confidence intervals were all less than $20\%$. All of these parameters met the criteria of KFDA for bioequivalence, indicating that $Lokpen^{TM}$ tablet is bioequivalent to $Loxonin^{TM}$ tablet.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.255-260
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• 2008

The purpose of this study was to evaluate the bioequivalence of the test (Daewoo Hydrocortisone 10 mg, Daewoo Pharm. Co., Busan, Korea) and reference (Jenapharm Hydrocortisone 10 mg, JayTech Biogen, Seoul, Korea) hydrocortisone tablets. Twenty-four healthy male Korean volunteers were divided into two groups with a randomized $2{\times}2$ cross-over design. In order to suppress the endogenous cortisol secretion, a single oral dose of Dexamethasone (4 mg) was administered 10 hr prior to hydrocortisone administration. Blood samples were withdrawn for 10 hr at the predetermined intervals after a single oral dose of hydrocortisone (20 mg). The serum concentration of hydrocortisone was analyzed by HPLC/UV using a column switching method after liquid-liquid extraction process. The pharmacokinetic parameters ($AUC_{0{\sim}10hr}$, $C_{max}$, and $T_{max}$) of the test and reference hydrocortisone tablets were determined while the secretion of endogenous cortisol was being suppressed. The pharmacokinetic parameters of the test tablet were not statistically different from those of the reference tablet at ex value was 0.05. The 90% confidence intervals for the average ratio (test/reference) of $AUC_{0{\sim}10hr}$ and $C_{max}$ were within the Korea Food and Drug Administration acceptance range of 0.80-1.25 ($0.89{\sim}0.99$ and $0.86{\sim}0.99$ for $AUC_{0{\sim}10hr}$ and $C_{max}$, respectively). Therefore it was concluded that the test tablet, Daewoo Hydrocortisone tablet was bioequivalent to the reference tablet, Jenapharm Hydrocortisone tablet.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.4111-4111
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• 2001

When a drug is prepared in a tablet, the active component represents only a small portion of the dosage form. The other components of the formulation include materials to assist in the dissolution, antioxidants, coloring agents and bulk fillers. The tablets are tested using approved testing methods usually involving separation and subsequent quantification of the active component. Tablets may also be tested by near-Infrared Reflectance spectrometry (NIRS). In the present study, based on NIRS and multivariate calibration methods, a novel and precise method is developed for direct determination of ascorbic acid in vitamin C tablet. Two different tablet formulations were powdered in three different sizes, 63-125 ${\mu}{\textrm}{m}$, and examined. Spectral region of 4750-4950 $cm^{-1}$ / was used and optimized for quantitative operations. Partial least squares (PLS) and multiple linear regression (MLR) methods were performed for this spectral region. The results of optimized PLS and MLR methods showed that reproducibility increase with decreasing grain size and standard error of calibration (SEP) of less than 1% w/w of ascorbic acid and a correlation coefficient of 0.998 can be achieved. The PLS method showed better results than MLR. Seven overdose and underdose samples (prepared in the laboratory to match marketed products) were tested by proposed and iodometric standard methods. A correlation between NIRS predicted ascorbic acid values and iodomet.ic values was calculated ($R^2$=0.9950). Finally, the direct analysis of individual intact tablets in their unit-dose packages (Blistering in aluminum and PVC foils) obtained from market were also carried out and a correlation coefficient of 0.9989 and SEP of 0.931% w/w of ascorbic acid were achieved.

• Journal of Pharmaceutical Investigation
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• v.41 no.6
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• pp.363-369
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• 2011

In this study, we demonstrated the release behavior of carvedilol with the content of polyvinylpyrrolidone K-30 (PVP K-30) and the effect of citric acid and fumaric acid as acidifiers on the release behavior of drug. In addition, it tries to inquire into the release behavior difference of the carvedilol according to the manufacturing method. The release behavior of the tablets was compared with Dilatrand$^{(R)}$ in the simulated gastric fluid (pH1.2). Differential scanning calorimeter (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were characterized for the physicochemical properties of the tablets. In case of mixing the carvedilol and PVP K-30, in case the ratio of the carvedilol and PVP K-30 was 1:5, the release behavior was the highest among. As well as the dissolution rate of tablets manufactured by lyophilization and rotary evaporator was higher than physical mixture. The dissolution rate of containing acidifiers was more improved. But, rather the excessive amount of the acidifier addition reduced the dissolution rate.

• Journal of Pharmaceutical Investigation
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• v.34 no.5
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• pp.407-411
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• 2004

New formulations of amlodipine maleate tablet have been investigated to enhance the stability of the drug against light and humidity. Three kinds of amlodipine maleate tablets were prepared. One is prepared by previously known formulation (formulation C), the others were by new formulations using hydrophilic polymer $(Opadry^{\circledR})$ coated granules (formulations A and B). Amlodipine maleate powder was coated with $Opadry^{\circledR}$ to produce the coated granules and it was mixed with other excipients to produce the tabletting mass of new formulations A and B. Dissolution rate of newly formulated tablets was over 80% within 10 minutes in 0.01 M HCl medium, and its dissolution pattern was similar to that of $Norvasc^{\circledR}$ tablet. After 6 months storage under accelerated conditions, residual drug contents of tested formulations (A and B) were not significantly different from formulation C, ranging from 96.2 to 100.4%. Meanwhile, dissolution amount of formulation C was significantly reduced compared to that of formulation A (p<0.05), showing formulation A was more stable than unprotected formulation C at the accelerated conditions. Results of appearance, hardness and disintegration remained unchanged during stability study. In conclusion, it showed that the new formulations had enhanced the stability characteristics and hydrophilic coating technique was an alternative and promising method to improve the stability of amlodipine maleate tablet.

• Journal of Pharmaceutical Investigation
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• v.28 no.3
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• pp.193-198
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• 1998

Bioequivalence of two cilostazol tablets, the $Pletaal^{TM}$ (Korea Otsuka Pharmaceutical Co., Ltd.) and the $Losazol^{TM}$ (Kyoung Dong Pharmaceutical Co., Ltd.), was evaluated according to the guideline of KFDA. Fourteen normal male volunteers (age $20{\sim}28$ years old) were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After two tablets containing 50 mg of cilostazol were orally administered, blood was taken at predetermined time intervals and the concentration of cilostazol in plasma was determined with an HPLC method using UV detector. The pharmacokinetic parameters $(C_{max},\;T_{max}\;and\;AUC_t)$ were calculated and ANOVA was utilized for the statistical analysis of parameters. The results showed that the differences in $C_{max},\;T_{max}\;and\;AUC_t$ between two tablets were 3.14%, 10.0% and 7.35%, respectively. The powers $(1-{\beta})$ for $C_{max},\;T_{max}\;and\;AUC_t$ were 89.67%, 80.97% and 83.87%, respectively. Detectable differences $({\Delta})$ and confidence intervals were all less than 20% except $T-{max}$, but confidence interval of $T_{max}$ was also less than 20% at the significance $level({\alpha})$ of 0.1. All of these parameters met the criteria of KFDA for bioequivalence, indicating that $Losazol^{TM}$ tablet is bioequivalent to $Pletaal^{TM} tablet$.