• Transactions on Electrical and Electronic Materials
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• 제13권1호
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• pp.2-5
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• 2012

We have designed, synthesized, and evaluated the physical properties of some high birefringence (${\Delta}n$) isothiocyanato biphenyl-bistolane liquid crystals. These compounds exhibit ${\Delta}n^-$ 0.4-0.7 at room temperature and wavelength $\lambda$=633 nm. Laterally substituted short alkyl chains and fluorine atom eliminate smectic phase and lower the melting temperature. The moderate melting temperature and very high clearing temperature make those compounds attractive for eutectic mixture formulation. Several mixtures based on those compounds were formulated and its physical properties evaluated.

• 분석과학
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• 제34권2호
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• pp.46-55
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• 2021

Evaluation of drug-excipient compatibility is one of the basic steps in the preformulation of pharmaceutical dosage forms. Some reactive excipients have been known so far which may cause stability problems for drug molecules in pharmaceutical dosage forms. The aim of this study was to evaluate drugexcipient compatibility of gliclazide with some common pharmaceutical excipients, known for their ability to incorporate in drug-excipient interactions. Binary mixtures were prepared using lactose, magnesium stearate, polyvinylpyrrolidone, sodium starch glycolate, polyethylene glycol 2000 and dicalcium phosphate. Based on the results; gliclazide was incompatible with all tested excipients; but not with dicalcium phosphate. DSC (Differential Scanning Calorimetry) results were in accordance with HPLC (High Pressure liquid chromatography) data and were more predictive than FTIR (Fourier Transform Infrared Spectroscopy). Drug and reactive excipients incompatibility was fully discussed and documented. It is advisable to avoid incompatible excipients or carefully monitor the drug stability when incorporating such excipients in final formulation designs.

• Biomolecules & Therapeutics
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• 제16권3호
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• pp.226-230
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• 2008

Monoolein-based cubic liquid crystalline systems were formulated for the local delivery of oregonin and hirsutanonol for the treatment of atopic dermatitis. The liquid crystalline phase and its nanodispersion containing drugs were prepared. The skin permeation and deposition properties of the drugs were examined in normal and delipidized rat skin. The proportion of oregonin (%) deposited in normal skin after topical administration of the drugs in the form of aqueous solution, cubic phase or cubic nanodispersions were $1.53\;{\pm}\;0.46$, $3.62\;{\pm}\;0.17$ and $5.13\;{\pm}\;0.73$, and those of hirsutanonol were $2.46\;{\pm}\;0.02$, $5.44\;{\pm}\;0.27$ and $17.28\;{\pm}\;2.19$, respectively. The greater lipophilicity and thus greater skin affinity of hirsutanonol than oregonin contributed the greater amount of skin deposition. The monoolein-based liquid crystalline phases significantly increased the amount of both drugs permeated and deposited. Approximately 3.2, 2.1 and 3.0 times greater amount of oregonin, and 3.4, 2.1 and 2.2 times greater amount of hirsutanonol were deposited in delipidized skin after administration of each drug in the form of aqueous solution, cubic phase and cubic nanodispersions system, respectively, because of lowered barrier function of the delipidized skin. In this study, the effects of drug property, vehicles type and skin condition on skin deposition and permeation properties of drug were examined and concluded that monoolein-based liquid crystalline systems would be a promising formulation for the local delivery of drugs.

• Mass Spectrometry Letters
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• 제13권4호
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• pp.146-151
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• 2022

Rotigotine (RTG) is a non-ergot dopamine agonist used to manage the early stage of Parkinson's disease (PD) as transdermal patch. However, the poor medication compliance of PD patients and skin issues related with repeated applications of RTG patches lead to the search for alternative formulations and it also requires appropriate analytical methods for their in vivo evaluation. Thus, here, a sensitive, efficient, and cost-effective method to determine RTG in rat plasma using liquid-liquid extraction (LLE) and multiple reaction monitoring was developed. The use of 20 µL of rat plasma for sample treatment, 8-OH-DPAT as the internal standard, and methyl tert-butyl ether as the LLE solvent in the present method gives it advantages over previous methods for the analysis of RTG in biological samples. The good analytical performance of the developed method was confirmed in specificity, linearity (the coefficient of determination ≥0.999 within 0.1-100 ng/mL), sensitivity (the lower limit of quantitation at 0.1 ng/mL), accuracy (81.00-115.05%), precision (≤10.75%), and recovery (81.00-104.48%) by following the FDA guidelines. Finally, the applicability test of the validated method to the in vivo evaluation of a RTG formulation showed that the present method is the only method which can be accurately applied to that longer than 24 hours, critical for the development of formulations with reduced dosing frequencies. Therefore, the present method could contribute to the development of new RTG formulations helpful to people suffering from PD.

• 한국유기농업학회지
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• 제20권3호
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• pp.345-356
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• 2012

본 연구는 2009년에 친환경 농산물 재배 농가들이 사용하는 자가 제조 액비 실태를 파악하고자 친환경 농산물 인증을 받은 29농가를 대상으로 액비의 종류, 재료, 제조과정, 활용방법 및 효과 등에 대해서 조사를 실시하였다. 농가에서 사용하는 액비의 재료는 대부분 주변에서 쉽게 구할 수 있는 것들이었고 제조방법은 주재료에 미생물의 에너지원으로 사용할 수 있는 당밀이나 흑설탕을 첨가하고 그리고 발효 미생물원으로 부엽토, 시판미생물, 시군센터에서 보급하는 미생물 또는 토착미생물 배양체를 사용하고 있었다. 농가에서 제조하여 활용하고 있는 액비 종류는 발효액비, 천혜녹즙, 아미노산액비, 칼슘액비, 인산액비 등 이었고 이들 액비는 생육촉진, 개화촉진, 꽃눈형성, 당도증가, 저장성 증대, 병해충 저항성 증가, 그리고 고온장해 억제 등의 효과가 있는 것으로 조사되었다. 수집된 액비의 성분분석 결과, pH와 EC의 범위는 시료간의 차이가 크며 질소, 인산 등 다량원소 함량은 대부분 적었으며 같은 재료를 이용하여 제조된 액비라도 제조방법에 따라 양분함량이 각각 다른 것으로 조사되었다.

• Journal of Pharmaceutical Investigation
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• 제37권2호
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• pp.85-94
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• 2007

The objective of this study is to prepare a stable delivery systems containing polyethoxylated retinamide(PERA) - derivatives of retinoic acid, effective anti-wrinkle and anti-acne agent. Cubic liquid crystalline phase gel (CLCPG) and cubosomes containing various concentrations of PERA were prepared to investigate the physicochemical properties. Furthermore, stability and transdermal absorption efficacy of the CLCPG containing PERA were investigated in comparison with oil-in-water (O/W) emulsions which are predominantly used as a topical formulation. CLCPG increase the stability of PERA in comparison with O/W emulsion. For tropical application, CLCPG containing PERA shows higher moisturizing effect than that of O/W emulsion. In skin permeation test, CLCPG shows higher PERA deposit on epidermis. With its specific physicochemical property caused by the glyceryl oleate, CLCPG itself could be used for stabilizer of various actives and applied as an effective delivery system for topical application. Cubosome, nano-sized dispersed CLCPG, is also expected to be applied in a various field of industry like food, cosmetics and pharmaceuticals.

• 공업화학
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• 제8권4호
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• pp.617-623
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• 1997

폴리솔베이트-핵산올-물의 3성분계의 상거동에 관한 메카니즘을 조사한 것으로, 등방성인 미셀영역에서 비등방성인 모자이크 액정상을 편광현미경에 의해 관찰하였다. 액정상 및 다른 상들은 약 20~70 wt% 범위에서 관측되었으며, 이 영역에서는 보다 안정한 유화계나 분산계의 포뮬레이션에 대한 기본적인 데이터를 제공할 수 있다. 알킬기의 탄소수 증가에 따라 3상 영역이 감소한 반면에, 2상 영역이 증가되었으며 비등방성 액정상은 관찰되지 않았다.

• 대한기계학회논문집B
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• 제27권9호
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• pp.1273-1281
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• 2003

The present study is mainly motivated to investigate the vaporization, auto-ignition, and combustion of liquid fuel spray injected into high pressure environment. The unsteady, multi-dimensional models were used for realistic simulation of spray as well as prediction of accurate ignition delay time. The Separated Flow (SF) model which considers the finite rate of transport between liquid and gas phases was employed to represent the interactions between spray and gas field. Among the SF models, the Discrete Droplet Model (DDM) which simulates the spray using finite number of representative samples of discrete droplets was adopted. The Eulerian-Lagrangian formulation was used to analyze the two-phase interactions. In order to predict an evaporation rate of droplet in high pressure environment, the high pressure vaporization model was applied using thermodynamic equilibrium and phase equilibrium at droplet surface. The high pressure effect as well as high temperature effect was considered in the calculation of liquid and gas properties. In case of vaporization, an interaction between droplets was studied through the simulation of spray. The interaction is shown up differently whether the ambient gas field is at normal pressure or high pressure. Also, the characteristics of spray behavior in high pressure environment were investigated through the comparison with normal ambient pressure case. In both cases, the spray behaviors are simulated through the distributions of temperature and reaction rate in gas field.

• 한국축산식품학회지
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• 제39권1호
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• pp.23-34
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• 2019

Fat reduction in the formulation of cheese emulsion causes problems in its flowability and functional characteristics during spray-dried cheese powder production. In order to eliminate these problems, the potential of using microparticulated whey protein (MWP) in cheese emulsions was examined in this study. Reduced-fat white-brined cheese emulsions (RF) with different dry-matters (DM) (15%, 20%, and 25% excluding emulsifying salt) were produced using various MWP concentrations (0%-20% based on cheese DM of emulsion). Their key characteristics were compared to full-fat cheese emulsion (FF). MWP addition had no influence on prevention of the phase separation observed in the instable group (RF 15). The most notable effect of using MWP was a reduction in apparent viscosity of RF which significantly increased by fat reduction. Moreover, increasing the amount of MWP led to a decrease in the values of consistency index and an increase in the values of flow behavior index. On the other hand, using high amounts of MWP made the emulsion more liquid-like compared to full-fat counterpart. MWP utilization also resulted in similar lightness and yellowness parameters in RF as their full-fat counterparts. MWP in RF increased glossiness and flowability scores, while decreased mouth coating scores in sensory analyses. Fat reduction caused a more compact network, while a porous structure similar to FF was observed with MWP addition to RF. In conclusion, MWP showed a good potential for formulation of reduced-fat cheese emulsions with rheological and sensorial characteristics suitable to be used as the feeding liquid in the spray drying process.

• 분석과학
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• 제32권4호
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• pp.147-154
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• 2019

Ampicillin and Sulbactam (2:1, w/w) are combined in formulation to provide broader antibacterial action in treatment of many infections. The development of analytical method for simultaneouly determine these two compounds was difficult because of the differences in their chemical structures and ratio in the formulation. Current published methods still have some limitations. In this study, we developed an alternative high-performance liquid chromatography (HPLC) assay method for simultaneously determination of ampicillin sodium and sulbactam sodium in powder for injection. Method validation of HPLC method was conducted to determine linearity, precision, accuracy, system suitability, robustness. The linearity of the calibration curves in the desired concentration range was good ($r^2$> 0.9994). RSDs of intra-day and inter-day precision obtained were less than 2.00 %. Accuracy was obtained with the recoveries in range of 98.42 % and 101.36 %. As a result of system suitability, RSD of both retention time and the peak area obtained were not more than 1.0 %. The values of plate number were more than 7000 and symmetric factors obtained were 0.8. As intermediate-precision and robustness of the developed assay, it could be expected to become valuable tools for revising the Korean Pharmacopoeia (KP XI).