• 폴리머
• /
• 제24권1호
• /
• pp.113-123
• /
• 2000

Poly(p-hydroxybenzoate) (PHB)/poly(ethylene terephthalate) (PET) 8/2공중합 폴리에스테르계 액정고분자와 poly(ethylene 2,6-naphthalate) (PEN) 및 poly(ethylene terephthalate)를 용융혼합하여 삼상계 블렌드물의 액정상 형성여부 및 기계적 성질을 조사하였다. PHB의 함량이 40 mo1%에서 급격한 점도의 감소로 토크의 값이 감소하였고, 인장강도와 초기 탄성율은 PHB의 함량이 증가함에 따라 액정고분자의 피브릴 형성으로 증가하였다. 섬유의 인장강도와 탄성율은 PHB의 함량과 권취속도를 증가시킴에 따라 증가하였고, 에스테르 교환반응은 용융혼합 시간에 따라 증가하였다. 에스테르 교환반응은 용융흔합물의 흔화성을 향상시키고, 동일 조성비의 단량체를 함유한 공중합체에서 나타나는 액정상을 형성하였다. PHB의 함량이 30 wt%에서는 부분적인 액정상이 나타나며, 40 wt%에서 삼상계 블렌드의 의사액정상이 나타났다.

• Journal of Pharmaceutical Investigation
• /
• 제40권6호
• /
• pp.339-345
• /
• 2010

Fenofibrate has been used for many years to lower cholesterol levels and its pharmacokinetic profile is well understood. However, due to its low solubility in water, it has low bioavailability after oral administration. In order to improve the dissolution rate, fenofibrate was formulated into a self-microemulsifying drug delivery systems (SMEDDS). We used pseudo-ternary phase diagrams to evaluate the area of microemulsification, and an in vitro dissolution test was used to investigate the dissolution rate of fenofibrate. The optimized formulation for in vitro dissolution assessment consisted of Lauroglycol FCC (60%), Solutol HS 15 (27%), and Transcutol-P (13%). The mean droplet size of the oil phase in the microemulsion formed from the SMEDDS was about 130 nm. The dissolution rate of fenofibrate from SMEDDS was significantly higher than that of the reference tablet. Our studies suggested that the fenofibrate containing SMEDDS composition can effectively increase the solubility and oral bioavailability of poorly water-soluble drugs.

• 한국세라믹학회지
• /
• 제21권4호
• /
• pp.313-322
• /
• 1984

Phase relationships of the pseudobinary systems in melanotekite-plumboferrite and melanotekite-magnetoplumbite in $PbO-Fe_2O_3-SiO_3$ system were obtained. Dielectric electric and magnetic properties were measured in the chosen pseudo-ternary system.

• 한국산학기술학회논문지
• /
• 제20권12호
• /
• pp.555-562
• /
• 2019

본 연구의 목적은 다양한 항균활성을 지닌 천연물 유래 물질 신남알데히드를 이용한 안정한 자가미세유화 약물전달시스템을 개발하는 것이다. 이러한 목표를 달성하기 위하여 신남알데히드의 주 분해산물인 신남산과 신남알데히드의 동시 정량법을 확립하였으며, 설정된 분석법을 이용한 용해도 시험으로 신남알데히드에 대한 용해도 개선효과가 우수한 계면활성제를 선별하였다. 계면활성제로 Cremophor EL, 공계면활성제로 Transcutol P를 이용한 신남알데히드의 pseudo-ternary phase diagram을 작성하여 에멀전의 입자크기를 최소화시킬 수 있는 조성비로 신남알데히드 : Cremophor EL : Trasncutol P = 10 : 70 : 20%(v/v/v)인 SMEDDS 조성물을 제조한 후 안정성 시험을 통해 신남알데히드의 함량변화 및 에멀전의 입자크기 변화에 대해 확인하였다. 본 연구를 통해 제조된 신남알데히드의 자가유화 나노에멀전은 신남산의 생성량이 적고 신남알데히드의 함량 저하 속도가 느려 안정성이 우수하였으며, 안정성 기간 중에 최초의 입자크기를 잘 유지하는 특성이 확인되었다. 따라서 이 조성물은 신남알데히드를 위한 의약품 제형으로의 활용 가능성이 높을 것으로 사료된다.

• Archives of Pharmacal Research
• /
• 제28권2호
• /
• pp.243-248
• /
• 2005

To improve the skin permeability of piroxicam, a new oil-in-water microemulsion containing $0.5\%$ piroxicam was developed. Among various oils investigated for their suitability as an oil phase for the microemulsion system, oleic acid showed both excellent solubility and skin permeation enhancing effect for piroxicam. Microemulsion existence ranges were identified through the construction of the pseudo-ternary phase diagram. The effect of the content of oleic acid and the ratio of the surfactant/cosurfactant on skin permeation of piroxicam were evaluated with excised rat skins. The optimum formulation with the highest skin permeation rate ($47.14\;{\mu}g/cm^2/h$) consisted of $0.5\%$ piroxicam, $10\%$ oleic acid, $60\%$ Labrasol/ethanol (1:5) and water.

• Journal of Pharmaceutical Investigation
• /
• 제39권6호
• /
• pp.417-422
• /
• 2009

Budesonide belongs to Class II in the Biopharmaceutics Classification System (BCS) for its high permeability and poor aqueous solubility. The purpose of this study was to improve the solubility and dissolution rate of budesonide using an o/w microemulsion system in order to develop a nasal formulation. Based on the results of the solubility study and pseudo ternary phase diagrams, microemulsions of about 80 nm in mean diameter were formulated using isopropyl myristate and Labrasol$^{(R)}$ as an oil phase and a surfactant, respectively. Solubility of budesonide in the microemulsions increased up to 6.50 mg/mL, which is high enough for a nasal formulation. In vitro release profiles of budesonide significantly increased from the microemulsions compared to that of the budesonide powder. These results suggest that the microemulsions of budesonide could further be developed into a clinically useful nasal formulation.

• Biomolecules & Therapeutics
• /
• 제21권2호
• /
• pp.173-179
• /
• 2013

Objective of present study was to prepare and characterize self-nanoemulsifying drug delivery system (SNEDDS) of lutein and to evaluate its effect on bioavailability of warfarin. The SNEDDS was prepared using an oil, a surfactant, and co-surfactants with optimal composition based on pseudo-ternary phase diagram. Effect of the SNEDDS on the bioavailability of warfarin was performed using Sprague Dawley rats. Lutein was successfully formulated as SNEDDS for immediate self-emulsification and dissolution by using combination of Peceol as oil, Labrasol as surfactant, and Transcutol-HP or Lutrol-E400 as co-surfactant. Almost complete dissolution was achieved after 15 min while lutein was not detectable from the lutein powder or intra-capsule content of a commercial formulation. SNEDDS formulation of lutein affected bioavailability of warfarin, showing about 10% increase in $C_{max}$ and AUC of the drug in rats while lutein as non-SNEDDS did not alter these parameters. Although exact mechanism is not yet elucidated, it appears that surfactant and co-surfactant used for SNEDDS formulation caused disturbance in the anatomy of small intestinal microvilli, leading to permeability change of the mucosal membrane. Based on this finding, it is suggested that drugs with narrow therapeutic range such as warfarin be administered with caution to avoid undesirable drug interaction due to large amount of surfactants contained in SNEDDS.

• 대한화학회지
• /
• 제56권6호
• /
• pp.720-724
• /
• 2012

Under pseudo-first order conditions, the monomeric species of Cr(VI) was found to be kinetically active in the absence of phenanthroline (phen) whereas in the phen-promoted path, the Cr(VI)-phen complex undergoes a nucleophilic attack by etane-1,2-diol to form a ternary complex which subsequently experience a redox decomposition leading to hydroxy ethanal and Cr(III)-phen complex. The effect of the cationic surfactant (CPC), anionic surfactant (SDS) and neutral surfactant (TX-100) on the unpromoted and phen-promoted path have been studied. Micellar effects have been explained by considering the preferential partitioning of reactants between the micellar and aqueous phase. Combination of TX-100 and phenanthroline will be the ideal for chromic acid oxidation of ethane-1,2-diol in aqueous media.

• Journal of Pharmaceutical Investigation
• /
• 제37권5호
• /
• pp.291-295
• /
• 2007

Prostaglandin $E_1\;(PGE_1)$ was formulated as two self-microemulsifying drug delivery systems (SMEDDS) composed of Cremophor $EL^{(R)}$ or Cremophor $ELP^{(R)}$ as a surfactant, ethanol as a cosurfactant and Labrafac $CC^{(R)}$ as an oil to develop liquid preparation for the treatment of erectile dysfunction. In pseudo-ternary phase diagram, viscous gel area and microemulsion area were defined. In the measurement of viscosity, the viscosity of two formulations increased gradually upon the addition of water and it decreased from the water contents over 40%. With excessive water, the present systems formed a microemulsion spontaneously. From these results, rte could expect that the present liquid $PGE_1$ SMEDDS formulations might stay within the urethra in the viscous state when contacting the moisture of the urethra and can be easily eliminated by urination. In long-term stability study, we could select one formulation more stable at the shelf storage condition of $4^{\circ}C$.

• 대한화학회지
• /
• 제57권6호
• /
• pp.703-711
• /
• 2013

In the present investigation, kinetic studies of oxidation of formic acid with and without catalyst and promoter in aqueous acid media were studied under the pseudo-first order conditions [formic acid]T ${\gg}[Cr(VI)]_T$ at room temperature. In the 1,10-phenanthroline (phen) promoted path, the cationic Cr(VI) phen complex is the main active oxidant species undergoes a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition through several steps leading to the products $CO_2$ and $H_2$ along with the Cr(III) phen complex. The anionic surfactant (i.e., sodium dodecyl sulfate, SDS) and neutral surfactant (i.e., Triton X-100, TX-100) act as catalyst and the reaction undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Whereas the cationic surfactant (i.e., N-cetyl pyridinium chloride, CPC) acts as an inhibitor restricts the reaction to aqueous phase. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. The neutral surfactant TX-100 has been observed as the suitable micellar catalyst for the phen promoted chromic acid oxidation of formic acid.