• Analytical Science and Technology
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• v.31 no.3
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• pp.107-111
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• 2018

Currently, ultraviolet-visible spectrophotometry and titration methods are used for assay tests of tramadol hydrochloride injection and raw material in the Korean Pharmacopoeia XI (KP XI). Titration has also been used in the British Pharmacopoeia (BP 2013) for the assay test of tramadol hydrochloride, and the HPLC assay for tramadol hydrochloride raw material has been used in the United States Pharmacopeia (USP 39). In this study, we developed an alternative HPLC assay method for tramadol hydrochloride injection that is up to date and specific, and employs the same method as tramadol hydrochloride capsules. Validation of the HPLC method was conducted to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of the calibration curves in the desired concentration range was good ($r^2$ > 0.9999). RSDs of intra-day precision obtained were 0.05-0.08 % and inter-day precision obtained were 0.08-0.19 %. Accuracy was obtained with recoveries in the range of 98.16 % and 100.90 %. As a result of the system's suitability, the RSD of both retention time and the peak area obtained were 0.07 %. The values of the plate number and tailing factor of tramadol hydrochloride obtained were 7076 and 1.16, respectively. Because of the intermediate precision and robustness of the developed assay, it is expected to become a valuable tool for revising the Korean Pharmacopoeia (KP XI).

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.9-18
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• 1993

Sugar spheres loaded with melatonin (MT) were coated with $Aquacoat^{\circledR}$ to control the release rate of MT over 8 hours. A zero-order release pattern over 8 hours was obtained with 20% coating on 8-10 mesh beads in USP basket dissolution studies. MT in 20% coated beads was quite stable at room temperature with less than 5% MT degraded during 6 months' storage. Dissolution profiles were also unchanged after 6 months. An oral preparation containing MT-loaded uncoated beads for immediate release and 20% coated beads with $Aquacoat^{\circledR}$ for controlled release over 8 hours was evaluated in six human subjects. When total 0.5 mg MT as low dose (immediate release portion of MT, 0.1 mg) was administered to four subjects, average peak plasma MT concentration was reached at about 600 pg/ml and maintained at about 10 pg/ml over 8 hours. Plasma MT concentration-time profiles were similar in shape to computer-simulated profiles. However, maximal plasma MT concentrations were three times greater compared to computer simulated curve. These results suggest that MT dose, ratio of immediate and controlled release MT, and pharmacokinetic parameters selected are adjusted to mimic endogenous MT concentration-time curve. In another study, 0.2 mg MT having 10% of immediate release portion and 80% controlled release portion produced plasma MT concentration-time curve which is more similar to endogenous profiles. A low bioavailability (<20%) may result from extensive first pass metabolism and remaining amounts of MT from controlled beads. A good correlation between plasma MT concentration and urinary excretion rate of 6-sulphatoxymelatonin (6-STMT), a major metabolite of MT was observed. As plasma MT concentration increased, urinary excretion rate of 6-STMT increased concomitantly. The linear relation between plasma MT and urinary excretion rate of 6-STMT was statistically significant. This result suggests that urinary 6-STMT may be used as an index of circadian rhythms of MT in humans.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.279-285
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• 2005

Ground CS-891 (N-[1-(4-methoxyphenyl)-1-methylethyl]-3-oxo-4-aza-5a-androst-1-ene-$17{\beta}$-carboxamide) of poorly water soluble drug was obtained using a Heiko Seisakusho model TI-100 vibration mill, and samples with different crystallinity were prepared at mixture ratios of 10:0, 7:3, 5:5, 3:7 and 0:10 (intact;ground CS-891). Physicochemical characterizations were obtained using qualitative and quantitative X-ray diffractometry, different scanning calorimetry (DSC), scanning electron microscopy (SEM), Quantasorb surface area analyzer, and controlled atmosphere microbalance. With increase of amorphous CS-891 in mixture ratios, the intensities of X-ray diffraction peaks of crystalline CS-891 were decreased, whereas surface area, water absorption, and exothermic peaks in DSC were increased. The apparent solubility of ground CS-891 was $4.4\;{\mu}g/ml$ and the solubility of intact CS-891 was $3.1\;{\mu}g/ml$ at $37{\pm}1^{\circ}C$. The apparent precipitation rates of CS-891 in a supersaturated solution during the solubility test were increased with an increase of amorphous CS-891, and a crystalline form of CS-891 transformed from amorphous CS-891 after the solubility test was found by X-ray diffraction analysis, DSC and SEM. The dissolution profiles of CS-891 with different crystallinity at $37{\pm}1^{\circ}C$ by the USP paddle method were investigated, and the apparent dissolution rate constant of ground CS-891 was about 5.9-fold higher than that of intact CS-891. A linear relationships between the crystallinity of CS-891 and the apparent dissolution rate constant (r>0.96) were obtained.

• Journal of Pharmaceutical Investigation
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• v.36 no.3
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• pp.161-167
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• 2006

The objective of this study was to investigate the dissolution patterns of variety of orally administered drug products available on the market. It aimed to understand their dissolution behaviors on the basis of the biopharmaceutics classification system (BCS) concept. On the tenets of BCS, several active pharmaceutical ingredients were selected: fluoxetine hydrochloride (class I), naproxen sodium (class ll), pyridostigmine bromide (class III), furosemide (class IV) and simvastatin (class IV). Typical dissolution media used in this study were pH 1.2, pH 4 & 6.8 phosphate buffers, and water. In cases, particular dissolution media specified in the KP and/or USP were used. Dissolution patterns of fluoxetine hydrochloride and pyridostigmine bromide products were characterized by their rapid release In addition, their dissolution characteristics were relatively unaffected by the type of a dissolution medium. Similar dissolution patterns were observed with pH 1.2, pH 4 & 6.8 phosphate buffers and water. By sharp contrast, poor dissolution patterns were noticed with naproxen sodium products, when pH 1.2 and pH 4 phosphate buffer were used. Improvements in its dissolution were achieved by switching the dissolution media to pH 6.8 phosphate buffer or water. Unsatisfactory dissolution data also were observed with a simvastatin product, when it was subject to dissolution tests by use of a surfactant-free pH 1.2, pH 4 & 6.8 phosphate buffers and water. All the release patterns reported in this study were best understood when BCS concepts were implemented. Our results demonstrated that a BCS-based drug classification should be considered first to choose a dissolution test/method and set up dissolution specification.

• Journal of Pharmaceutical Investigation
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• v.38 no.3
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• pp.177-182
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• 2008

The purposes of this study were to prepare dual-layered coated compact pellets containing three nutrients Glucose, Chromium picolinate, Vitamin C) for rumen bypass. The core compact pellets were prepared by an extrusionspheronization method and then double layered coated with pH independent EC (ethyl cellulose) and pH-dependent polymers ($Eudragit^{(R)}$ E100) using a fluid-bed spray coater. Depending on the coating levels of EC and $Eudragit^{(R)}$ E100, release profiles were variable in simulated rumen (pH 6.8) and abomasums (pH 2.0) fluid using USP apparatus I (basket method). When compact pellets were coated with EC (about 10% level in inner layer) and then $Eudragit^{(R)}$ E100 (20% level in outer layer) in a dual-layered manner, rumen-bypass delivery resisting rumen fluid followed by release in abomasums fluid could possible. The friability was also satisfactory based on chewing behavior of ruminants. The dual-layered coated compact pellets showed smooth surface and distinct inner/outer layers using scanning electron microscopy (SEM). The current rumen bypass delivery system can be also applicable to deliver other nutrients in ruminants.

• Advances in nano research
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• v.5 no.3
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• pp.215-230
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• 2017

The development of hybrid systems comprising nanoparticles and polymers is an opening pathway for engineering nanocomposites exhibiting outstanding mechanical, optical, electrical, and magnetic properties. Among inorganic counterpart, iron oxide nanoparticles (IONP) exhibit high magnetization, controllable surface chemistry, spintronic properties, and biological compatibility. These characteristics enable them as a platform for biomedical applications and building blocks for bottom-up approaches, such as the layer-by-layer (LbL). In this regard, the present study is addressed to investigate IONP synthesised through co-precipitation route (average diameter around 7 nm), with either positive or negative surface charges, LbL assembled with sodium sulfonated polystyrene (PSS) or polyaniline (PANI). The surface and internal morphologies, and electrochemical properties of these nanocomposites were probed with atomic force microscopy, UV-vis and Raman spectroscopy, scanning electron microscopy, cross-sectional transmission electron microscopy, and electrochemical measurements. The nanocomposites display a globular morphology with IONP densely packed while surface dressed by polyelectrolytes. The investigation of the effect of thermal annealing (300 up to $600^{\circ}C$) on the oxidation process of IONP assembled with PSS was performed using Raman spectroscopy. Our findings showed that PSS protects IONP from oxidation/phase transformation to hematite up to $400^{\circ}C$. The electrochemical performance of nanocomposite comprising IONP and PANI were investigated in $0.5mol{\times}L^{-1}$ $Na_2SO_4$ electrolyte solution by cyclic voltammetry and chronopotentiometry. Our findings indicate this structure as promising candidate for potential application as electrodes for supercapacitors.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.244-251
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• 2010

Standardized parenteral nutrition is required to improve patient's safety, clinical appropriateness and to increase uniformity between institution and institutions. We assessed the consistency with the American society for parenteral and enteral nutrition (A.S.P.E.N.) practice guideline for PN by evaluating current practice process for parenteral nutrition formulation in inpatients pharmacies in Korea. Each question in this survey was based on 2007 A.S.P.E.N. recommendations of standard parenteral nutrition formulation, the American society of health-system pharmacists (ASHP), and the United State Pharmacopoeia (USP) Chapter 797 guideline for compounding parenteral nutritions. All 90 Korean society of hospital pharmacist (KSHP) member directors of pharmacy were requested to respond to the survey in order to compare the survey results to ASHP national survey of pharmacy practice in hospital settings (2002) in compliance with A.S.P.E.N. guideline. We had final response rate of 35.6%. 25 (100%) hospitals complied with this Garb guideline (response rate was 84.4%) which was the highest compliance. Only 17.9% of hospital pharmacies were actively involved in complications monitoring. Monitoring complications and efficacy were least in compliance with the A.S.P.E.N. guideline. 69.0% of Korean pharmacists adjusted medication dosage based on disease state or monitoring laboratory data in compliance with the A.S.P.E.N. guideline. Over 50% of the hospital pharmacies failed to provide and evaluate staff training in aseptic manipulation skills periodically. Korean hospital pharmacies need to comply with the standard practice guideline for compounding sterile preparation in order to provide better quality of parenteral nutrition service for specific patient population.

• Archives of Pharmacal Research
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• v.28 no.1
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• pp.120-126
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• 2005

The objective of this study was to investigate the effects of sodium lauryl sulfate upon the saturation solubility of carbamazepine, its dissolution kinetics, and $T_{50\%}$ defined as the time required for dissolving $50\%$ of carbamazepine. Water, 0.1N-HCI, and phosphate buffers at pH 4.0 and 6.8 containing 0.1, 0.5, 1, and $2\%$ sodium lauryl sulfate were used as dissolution media. The dissolution study was conducted by using the USP dissolution apparatus II with an agitation rate of 75 rpm. Samples of the dissolution media were taken in 7, 15, 30, 45, 60, 75, and 90 min, and the amounts of carbamazepine were determined spectrophotometrically at 285 nm. All dissolution data were fitted well into a four-parameter exponential equation: $Q\;=\;a(1\;-\;e^{-bxt})\;+\;c(1\;-\;e^{-dxt})$. In this equation Q represented $\%$ carbamazepine dissolved at a time t, and a, b, c, and d were constants. This equation led to the calculation of dissolution rates at various time points and $T_{50\%}$. It was found that the dissolution rate of carbamazepine was directly proportional to the aqueous concentration of sodium lauryl sulfate. In addition, under our experimental conditions $T_{50%}$ values ranged from 37.8 to 4.9 min. It was interesting to note that $T_{50\%}$ declined rapidly as the surfactant concentration increased from 0.1 to $0.5\%$, whereas it declined more slowly at concentrations greater than $1\%$. These results clearly demonstrated that the dissolution rate of carbamazepine and duration of its dissolution test could be tailored by optimizing the amount of sodium lauryl sulfate in a dissolution medium.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.135-145
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• 2012

This study is a research development case study on the free-standing Network based camera video recording DVR. The DVR devices till now have recorded data by converting and compressing analogue video to digital, but in the future, digital videos will be recorded directly through the network camera. Also, digital compressing methods are progressing from MPEG-4, MJPEG, to H.264 method, with products considering high definition compression efficiency, minimized data size, network compatibility, and fast pending time. According to this, in 2012, it is predicted that network camera and video devices throughout the world will outrun the current analogue devices. With this transition of technological environment and fast product pending speed, a new, quality focused design is required for product development including technical realization, reliability, high-definition, compression technology, will be essential. Manufacturers are researching a new direction for the product appearance. This study considers the actual end-users as the design target and through consumer survey on preferences, design needs and required elements necessary in the design development process are extracted. Furthermore, usability and preferred images were explored through literature study and market research. Through this research process, appropriate forms for the network based DVR were analyzed, and applied into the design development process. This product will take into consideration its competitiveness and the significance of USP(Unique Selling Proposition) which is the design supremacy and professional technical skills.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.414-421
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• 2011

시중에 유통 중인 영양보충용 제품의 수용성 비타민 $B_1$(thiamin), $B_2$(riboflavin), $B_3$(nicotinic acid and nicotine amide), $B_6$(pyridoxine), C(ascorbic acid)의 신속한 동시분석 방법을 확립하기 위하여 본 연구를 실시하였다. 영양보충용 제품은 정제, 연질캅셀, 분말, 액상의 4가지 제형에 대해 27종의 제품을 구입한 후, Ion-pair 분리기법을 사용하여 HPLC-UVD를 이용한 동시분석 방법을 검토하였다. 비타민 $B_1$, $B_2$, $B_3$, $B_6$, C의 HPLC에 의한 동시분석 조건을 검토한 결과, 이동상은 0.02% triethylamine, 17.5% 메탄올, $5{\mu}M$ sodium hexanesulfonic acid가 함유된 pH 3.5(acetic acid로 조절)의 수용액을 사용하였고, 용출시간은 다른 피크의 영향을 받지 않도록 30분으로 하였다. 수용성 비타민의 회수율은 96% 이상이었다. 본 연구에 의해 확립된 수용성 비타민의 동시분석 조건은 검량선의 직선성, 정밀성, 정확성, 기기적합성 등이 USP 및 ICH 기준에 적합하여 HPLC의 동시분석 방법으로 합당하였다. 수용성 비타민의 추출 용매는 제형에 따라 약간의 차이를 보이긴 했으나, 물이나 산성조건을 갖춘 HPLC의 이동상이 에탄올이나 메탄올보다 높은 추출 효율을 보였다. 초음파 추출기에 의한 추출 시간은 20분이 가장 적당하였다. 본 연구의 결과는 수용성 비타민의 신속한 추출 및 분석에 매우 효율적으로 이용될 것으로 기대된다.