• Archives of Pharmacal Research
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• v.17 no.4
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• pp.240-243
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• 1994

Release rates of flurbiprofen from transdermal gels made of poloxamer 407 were evaluated using a membraneless diffusion cell in order to study the effects of formulation variables on flurbiprofen release such as poloxamer 407 (17.5-25%) drug (0.1-1.0%), ethanol (10-20%), PG or PEF 300 (5-15%) concentrations and gel pH(3-7). Isopropyl myristate was employed as a receptor medium for the drug released from the gel. The diffusion coefficient of flurbiprofen decreased linearly as the amount of poloxamer 407 and the drug in the gel increased. The release rate of flurbiprofen was gel increased. The The addition of more ethanol in the gel increased the drug release, resulting from the increase of the thermodynamic activity of the drug in the aqueous phase of the gel. However, the concentration effects of PG and PEG 300 on the release rate of flurbiprofen were negligible over the concentration range used.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.27-32
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• 1994

In order to reduce systemic side effects following oral administration, flurbiprofen was formulated as transdermal gels consisting of the drug, poloxamer 407 and ethanol in buffer solutions. The effect of formulation variables in the preparation of flurbiprofen gels on skin permeation of the drug was evaluated using Keshary-Chien diffusion cells fitted with excised rat skins. The permeation rate of flurbiprofen through rat skin was directly proportional to initial drug concentration (between 0.1% and 1.0%) in the gel while it was inversely proportional to poloxamer 407 concentration (between 17.5% and 25%). The skin permeation of flurbiprofen was substantially influenced by the gel pH between 3 and 7, exhibiting a maximum at pH 4. The concentration effect of ethanol on the permeation of the drug was negligible in the concentration range of $10{\sim}20%$.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.39-43
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• 2007

Previously, we have reported that PLGA nanoparticles were prepared for sustained release of water-soluble blue dextran and the particle size, in vitro release pattern and encapsulation were modulated by varying polymers. This study was designed to encapsulate plasmid DNA in PLGA nanoparticles and to investigate the effect of Polymers and temperatures. PLGA nanoparticles were fabricated with poloxamer 188 (P188) or poloxamer 407 (P407) by using spontaneous emulsification solvent diffusion method. As a model plasmid DNA, pCMV-Taq2B/1L-18 was encapsulated in PLGA nanoparticles. Then, the particle size, zeta potential and encapsulation efficiency of nanoparticles containing plasmid DNA were investigated. Particle sizes of PLGA nanoparticles prepared with P188 and P407 were in the range of 200-330 nm and 250-290 nm, respectively. Zeta potentials of nanoparticles were negative regardless of nanoparticle compositions. Encapsulation efficiency of P407 nanoparticles prepared at $30^{\circ}C$ was higher than those at other preparation condition. From the results, the PLGA nanoparticles prepared with poloxamers at different temperature, could modulate the particles size of nanoparticles, and encapsulation efficiency of plasmid DNA.

• The Korean Journal of Food & Health Convergence
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• v.4 no.4
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• pp.1-9
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• 2018

To determine the effect of Vitex doniana (leaves stem and root bark) ethanolic extracts on lipid profiles of Poloxamer 407 (P407) induced hyperlipidemic and normal rats. Fifty four mixed sex rats weighing 100-200g were divided into nine groups comprising six animals per group. At the end of the 21 day, the animals were sacrificed and blood sample were collected for determination of serum levels of: Total cholesterol (TC), Triacylglycerides (TAG), High-density lipoprotein cholesterol (HDL-c) and Low-density lipoprotein cholesterol (LDL-c). The studies showed that all induced treated groups significantly (P<0.05) lower serum levels of TC, TAG, LDL-c and significantly (P<0.05) increased HDL-c when compared to the P407 induced hyperlipidemic control. The normal treated groups showed no significant (P>0.05) difference in the serum levels of TC, TAG, LDL and HDL when compared to the normal control group. Calculation of atherogenic risk predictor indices of the induced treated groups showed that all the extracts significantly (P<0.05) lowered the LDL-c/HDL-c, log (TAG/HDL-c) and significantly (P<0.05) increased HDL-c/TC ratio when compared to the P407 induced hyperlipidemic control group. The atherogenic risk predictor indices of normal treated groups showed no significant difference (P>0.05) in LDL-c/HDL-c, Log (TAG/HDL-c) and HDL-c/TC ratio when compared to the normal control group. The study demonstrates the phytotherapeutic effect of Vitex doniana (leaves, stem and root bark) ethanolic extract in poloxamer 407 induced hyperlipidemia.

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.277-283
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• 2010

CoQ with low melting temperature was exploited to improve its solubility by preparing its solid dispersions (SDs) with a meltable polymer, poloxamer 407 (P 407). P407 can be utilized for a relatively simple, quick, inexpensive, reproducible and potentially scalable manner in the low temperature melting method. CoQ 10 solubility and dissolution increased with increasing concentrations of P 407 in SDs. Comparison of the enhanced dissolution of CoQ 10 from different poloxamers suggested that the preparation of CoQ 10 SDs using P 407 as a meltable hydrophilic polymer carrier could be a promising approach to improve its dissolution.

• Journal of Pharmaceutical Investigation
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• v.25 no.2
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• pp.129-136
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• 1995

In order to reduce the systemic side effects and the gastrointestinal irritation of indomethacin following its oral administration, the drug was formulated as a transdermal gel using poloxamer 407. In vitro diffusion cells fitted with excised rat skins were used to evaluate the effects of formulation variables on skin permeation of indomethacin from poloxamer gels. The formulation variables were the concentrations of indomethacin, poloxamer 407 and ethanol, and the gel pH. The increase of the drug amount in the gel from 0.5% to 2.0% induced a direct but nonlinear increase in the skin permeation rate of indomethacin. The increase of poloxamer concentration from 17.5% to 25% in the gel resulted in a decrease of skin permeation rate of indomethacin, which was due to a reduction in the amount of free drug molecules available for permeation through skin by entrapping more drug molecules within the micelles formed by poloxamer. The increase of ethanol concentration from 10% to 20% in the gel resulted in a linear increase of permeation rate of indomethacin through skin, possibly due to the penetration enhancing effect of ethanol. The skin permeation of indomethacin was substantially influenced by the gel pH, exhibiting a maximum at pH 4.

• The Journal of Internal Korean Medicine
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• v.26 no.4
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• pp.820-827
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• 2005

연구목적: 본 연구는 Poloxamer-407로 유발시킨 고지혈증에 대한 청간탕의 효과를 알아보기 위해 수행되어졌다. 실험방법: Poloxamer-407로 쥐에 고지혈증을 유발시킨후 청간탕과 Lipidil을 경구 투여하여 혈청 cholesterol, 고밀도 지단백, 중성지질을 측정하였으며, 지질대사와 관련된 ACAT, DGAT, $CYP7{\alpha}H$, LDL receptor의 gene expression을 RT-PCR를 통해 비교 분석하였다. 실험결과: 청간탕 투여군은 혈청 콜레스테롤을 각각 32% 와 65% (p<0.05)로, 혈청 중성지방을 각각 21% 와 51% (p<0.05)로 감소시켰다. 또한, 청간탕은 LDL 수용체와 $CYP7{\alpha}H$ 유전자 발현을 증가시켰다. 결론: 이상의 연구로부터 우리는 청간탕이 지질의 흡수, 저장을 억제하고 콜레스테롤의 분비를 촉진함으로써 고지혈증에 일정한 효과가 있음을 알 수 있었다.

• The Korean Journal of Urological Oncology
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• 제15권3호
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• pp.178-186
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• 2017

Purpose: Poloxamer 407 (P407) thermo-sensitive hydrogel formulations were developed to enhance the retention time in the urinary bladder after intravesical instillation. Materials and Methods: P407 hydrogels (P407Gels) containing 0.2 w/w% fluorescein isothiocyanate dextran (FD, MW 4 kDa) as a fluorescent probe were prepared by the cold method with different concentrations of the polymer (20, 25, and 30 w/w%). The gel-forming capacities were characterized in terms of gelation temperature (G-Temp), gelation time (G-Time), and gel duration (G-Dur). Homogenous dispersion of the probe throughout the hydrogel was observed by using fluorescence microscopy. The in vitro bladder simulation model was established to evaluate the retention and drug release properties. P407Gels in the solution state were administered to nude mice via urinary instillation, and the in vivo retention behavior of P407Gels was visualized by using an in vivo imaging system (IVIS). Results: P407Gels showed a thermo-reversible phase transition at $4^{\circ}C$ (refrigerated; sol) and $37^{\circ}C$ (body temperature; gel). The G-Temp, G-Time, and G-Dur of FD-free P407Gels were approximately $10^{\circ}C-20^{\circ}C$, 12-30 seconds, and 12-35 hours, respectively, and were not altered by the addition of FD. Fluorescence imaging showed that FD was spread homogenously in the gelled P407 solution. In a bladder simulation model, even after repeated periodic filling-emptying cycles, the hydrogel formulation displayed excellent retention with continuous release of the probe over 8 hours. The FD release from P407Gels and the erosion of the gel, both of which followed zero-order kinetics, had a linear relationship ($r^2=0.988$). IVIS demonstrated that the intravesical retention time of P407Gels was over 4 hours, which was longer than that of the FD solution (<1 hour), even though periodic urination occurred in the mice. Conclusions: FD release from P407Gels was erosion-controlled. P407Gels represent a promising system to enhance intravesical retention with extended drug delivery.

• Journal of Pharmaceutical Investigation
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• v.25 no.3
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• pp.177-184
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• 1995

In order to formulate an aqueous topical preparation of epidermal growth factor(EGF) for the treatment of open wound and bum, the stability of EGF in aqueous vehicles containing various stabilizers was evaluated and the pharmacological activity of gel preparations formulated with poloxamer 407 was determined with wound model. Various additives, which are known as potent stabilizers for proteins and polypeptides so far, were used to increase the stability of EGF in aqueous vehicles. The contents of EGF in the vehicles containing stabilizers were determined with an HPLC method after the storage at $37^{\circ}C$. EGF was more stable in ultrapure water than RO water or saline. All the additives studied resulted in deleterious effects on EGF stability. Therefore, it was speculated that any additives or impurities in the vehicle made EGF unstable. However, nitrogen purge of solution increased the stability of EGF in aqueous vehicles. The aqueous topical preparations of EGF were formulated with poloxamer 407 as a gel base in saline. Gelatin or amastatin was employed as a protease inhibitor. The pharmacological effect of EGF gel was studied with open wound model in mice. EGF preparations, made of oleaginous base or poloxamer gel base, showed significant healing effect compared to the control group(p<0.05). The addition of protease inhibitor in poloxamer 407 gel resulted in significant healing effect compared to the gel without it(p<0.05). Body weights of mice treated with EGF preparation were increased at the first day after the formation of open wound, while those of the control group were decreased. The EGF gel made of poloxamer 407 containing a pretense inhibitor would be a promising aqueous topical preparation for EGF.

• Polymer(Korea)
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• v.36 no.4
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• pp.500-506
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• 2012

In this study, we developed and optimized hydrophilic polymer based solid dispersion formulations (SDs) for enhancing the aqueous solubility of eprosartan, one of poorly soluble drugs, that has been broadly used for the treatment of high blood pressure. Poly(ethylene glycol) (PEG) and poly(vinyl pyrrolidone) (PVP) based SDs were prepared by hot melting and solvent evaporation methods and the drug/polymer composition varied in the range of 1:1~1:5 with or without poloxamer 407 (P407) as a polymeric surfactant. The SDs prepared by solvent evaporation showed more reduced crystallinity than ones by hot melting, and PVP based SDs showed more enhanced solubility and lower crystallinity than PEG based SDs. Furthermore, it was observed from DSC and PXRD analysis that the SDs with P407 (drug:polymer: P407 = 1:5:1) demonstrated no crystallinity and the most enhanced solubility (more than 3~4 times).