• Title/Summary/Keyword: solvent effect

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Effect of Tripolyphosphate (TPP) on the Controlled Release of Cyclosporin A from Chitosan-coated Lipid Microparticles

  • Cheon, Ji-Woong;Shim, Chang-Koo;Chung, Suk-Jae;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • v.39 no.1
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    • pp.59-63
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    • 2009
  • Soybean phosphatidylcholine microparticles loaded with cyclosporin A (CsA) were prepared by the modified emulsion solvent diffusion and ionic gelation method, in which chitosan on the surface of the microparticles was crosslinked with various concentrations of tripolyphosphate (TPP). The morphology of the particles was characterized by scanning electron microscopy (SEM). The change of particle size and zeta-potential by chitosan on the surface of the lipid microparticles were systematically observed. The encapsulation efficiency and loading capacity of CsA in the particles were determined by high performance liquid chromatography (HPLC). In vitro release kinetics was studied using the dialysis method. In the results, the mean particle size and the zeta-potential of lipid microparticles increased when the attached chitosan was cross-linked (from 2.5 to 6.2 ${\mu}m$ and from -37.0 to +93.0 mV, respectively). The cyclosporin A-loaded lipid microparticles appeared discrete and spherical particles with smooth surfaces. The encapsulation efficiency of CsA was between 79% and 90% while the loading capacity was between 41% and 56%. In vitro release study showed that the crosslinkage of chitosan by TPP significantly delayed the release of CsA from the particles in a concentration-dependent manner. Thus, the release of CsA from the lipid microparticles could be controlled by tripolyphosphate used as a cross-linking agent.

Effect of some factors on extraction of effectual components in cinnamon extracts (추출조건이 계피추출액의 유효성분함량에 미치는 영향)

  • Kim, Na-Mi;Ko, Sung-Ryong;Choi, Kang-Ju;Kim, Woo-Jung
    • Applied Biological Chemistry
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    • v.36 no.1
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    • pp.17-22
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    • 1993
  • Effects of temperature, time, solvent addition ratio and number of extraction on contents of effectual components and soluble materials of cinnamon extracts were studied. All of the chemical contents of proximate composition and cinnamic acid, cinnamic aldehyde and eugenol were significantly increased as the extraction temperature increased from $20^{\circ}C$ to $80^{\circ}C$, while little change measured at $100^{\circ}C$. During ten hours of extraction at $80^{\circ}C$, more than six hours extraction showed a little increase effects the contents of cinnamic aldehyde, eugenol and proximate components. The ratio of solvents added to dried cinnamon also showed improving effects of chemical properties as the ratio increased from 5 to 40 times. Two times of extractions for 1 hour was found to be effective to recover those components.

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Isolation and characteristics of hyper-butanol producing OBT7 mutant of Clostridium saccharoperbutylacetonicum N1-4 (클로스트리디움 싸카로퍼부틸아세토니컴 N1-4주(株)로부터 부타놀 다량생산주(株) OBT 돌연변이의 분리와 특성)

  • Ahn, Byoung-Kwon
    • Applied Biological Chemistry
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    • v.36 no.1
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    • pp.38-44
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    • 1993
  • 1) OBT7 mutant was isolated by W light-butanol tolerance from Clostridium saccharoperbutylacetonicm ATCC 13564 (N1-4 strain). The mutant produced 16.5 g/l (1.4-fold increase) of n-butanol, 4.65 g/l (1.5-fold increase) of acetone, and 21.5 g/l of total solvent. It was suggested that clostridial bacteria producing n-butanol does not have a poor effect on misrepair via an error-prone pathway by UV light-butanol tolerance. 2) Compared to glucose fermentation, in mannitol fermentation, OBT7 mutant did not produce acetone and acetic acid. And the ratios of n-butanol and ethanol to total solvents increased by 10.3% and 10.5%, respectively, totalling 20.8%, while the ratio of acetone was decreased by 21.2%. Also the maximum ratio of n-butanol to total solvents reached 94.8%. These results indicated that oxidized compound (acetone, acetic acid, and butyric acid) was converted to the reduced compounds (n-butanol, and ethanol). Therefore, mannitol can be used to eliminate by-products of oxidized compound.

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Anti-Mullerian Hormone Serum Concentrations in Prenatal and Postnatal Period in Murine

  • Kim, Dae Young
    • Journal of Embryo Transfer
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    • v.28 no.2
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    • pp.149-155
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    • 2013
  • Mullerian inhibiting substance (MIS) is a member of the TGF-${\beta}$ (transforming growth factor-${\beta}$) family whose members play key roles in development, suppression of tumour growth, and feedback control of the pituitary-gonadal hormone axis. MIS is expressed in a highly tissue-specific manner in which it is restricted to male Sertoli cells and female granulose cells. The serum levels of MIS in prenatal and postnatal ICR mice were measured using the enzyme-linked immuno-solvent assay (ELISA) using the MIS/AMH antibody. Mice were grouped by age: the significant periods were at the onset of development. During sex organ differentiation, no remarkable difference between female and male foetus MIS serum levels (both<0.1 ng/ml) was observed. However, MIS serum levels in pregnant mice markedly changed (4.5~12.2 ng/ml). After birth, postnatal female and male mice serum MIS levels changed considerably (male: <0.1~138.5 ng/ml, female: 5.3~103.4 ng/ml), and the changing phase were diametrically opposed (male: decreasing, female: fluctuating). These findings suggest that MIS may have strong associations with not only develop-ment but also puberty. For further studies, establishing the standard MIS serum levels is of importance. Our study provides the basic information for the study of MIS interactions with reproductive organ disability, cancer, and the effect of other hormone or menopause. We hypothesise that if MIS is regularly injected into middle-age women, meno-pause will be delayed. We detected that serum MIS concentration curves change with age. The changing phase is different between males and females, and this difference is significant after birth. Moreover, MIS mRNA is expressed during the developmental period (prenatal) and also in the postnatal period. This finding indicates that MIS may play a significant role in the developmental stage and in growth after birth.

Effect of spinning parameters of polyethersulfone based hollow fiber membranes on morphological and mechanical properties

  • Tewfik, Shadia R.;Sorour, Mohamed H.;Shaalan, Hayam F.;Hani, Heba A.
    • Membrane and Water Treatment
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    • v.9 no.1
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    • pp.43-51
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    • 2018
  • Hollow fiber (HF) membranes are gaining wide interest over flat membranes due to their compaction and high area to surface volume ratio. This work addresses the fabrication of HF from polysulfone (PS) and polyethersulfone (PES) using N-methylpyrrolidone (NMP) as solvent in addition to other additives to achieve desired characteristics. The semi-pilot spinning system includes jacketed vessel, four spinneret block, coagulation and washing baths in addition to dryer and winder. Different parameters affecting dry-wet spinning phase inversion process were investigated. Dope compositions of PES, NMP and polyvinyl pyrrolidone (PVP) of varying molecular weights as additive were addressed. Some critical parameters of importance were also investigated. Those include dope flow rate, air gap, coagulation & washing baths and drying temperatures. The measured dope viscosity was in the range from 1.7 to 36.5 Pa.s. Air gap distance was adjusted from 20 to 45 cm and coagulation bath temperature from 20 to $46^{\circ}C$. The HF membranes were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and mechanical properties. Results indicated prevalence of finger like structure and average surface roughness from about 29 to 78.3 nm. Profile of stress strain characteristics revealed suitability of the fibers for downstream interventions for fabrication of thin film composite membrane. Different empirical correlations were formulated which enable deeper understanding of the interaction of the above mentioned variables. Data of pure water permeability (PWP) confirmed that the fabricated samples fall within the microfiltration (MF)-ultrafiltration (UF) range of membrane separation.

Preparation of Dexamethasone-21-palmitate Incorporated Lipid Nanosphere: Physical Properties by Varying Components and Ratio of Lipid (팔미틴산덱사메타손이 봉입된 지질나노입자의 제조: 지질종류와 함량에 따른 물리적 특성)

  • Jung, Suk-Hyun;Lee, Jung-Eun;Seong, Ha-Soo;Shin, Byung-Cheol
    • Journal of Pharmaceutical Investigation
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    • v.36 no.6
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    • pp.355-361
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    • 2006
  • Intraarticular corticosteroid injections for therapy of rheumatic arthritis are administered with the aim of optimal local anti-inflammatory effect at the injection site. Since the side effects of corticosteroidal drug, dexamethasone(DEX), administered at hish dose limited the therapeutic efficacy, there was a need to design a new drug delivery system for controlled release of dexamethasone. As a prodrug for continuous therapeutic efficacy, dexamethasone-21-palmitate(DEX-PAL) was prepared via esterification of palmitoyl chloride and dexamethasone. DEX-PAL was identified by NMR and MASS analysis. DEX-PAL or DEX was entrapped in lipid nanosphere which could be prepared by using a self emulsification-solvent evaporation method. Physicochemical characteristics such as mean particle diameter, zeta potential and drug loading efficiency of the lipid nanospheres were investigated with variation of either the kind of lipid or the lipid composition. The lipid nanospheres had a mean diameter $83{\sim}95$ nm and DEX-PAL loading efficiency of up to 95%. The drug loading efficiency increased with the increase of aliphatic chain length attached to the phospholipid. The incorporation of cationic lipid was very efficient for both reducing particle size of lipid nanospheres and enhancing drug loading efficiency. The lipid nanospheres containing DEX-PAL may be a promising novel drug carrier for the controlled release of the poorly water-soluble drugs.

Mechanistic insights of metal acetylacetonate-aided dehydrocoupling of liquid-state ammonia borane NH3BH3

  • Pereza, Manon;Mieleb, Philippe;Demirci, Umit B.
    • Advances in Energy Research
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    • v.4 no.2
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    • pp.177-187
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    • 2016
  • Ammonia borane $NH_3BH_3$ solubilized in organic solvent is a potential liquid-state chemical hydrogen storage material. In this study, metal acetylacetonates like $Fe(O_2C_5H_7)_3$, $Co(O_2C_5H_7)_2$, $Ni(O_2C_5H_7)_2$, $Pd(O_2C_5H_7)_2$, $Pt(O_2C_5H_7)_2$ and $Ru(O_2C_5H_7)_3$ are considered for assisting dehydrocoupling of ammonia borane in diglyme (0.135 M) at $50^{\circ}C$. The molar ratio between ammonia borane and metal acetylacetonate is fixed at 100. A protocol for the separation of the soluble and insoluble fractions present in the slurry is proposed; it consists in using acetonitrile to make the precipitation of metal-based compounds easier and to solubilize boron-based intermediates/products. The nature of the metal does not affect the dehydrocoupling mechanisms, the $^{11}B\{^1H\}$ NMR spectra showing the formation of the same reaction intermediates. The aforementioned metal acetylacetonates do mainly have effect on the kinetics of dehydrocoupling. Dehydrocoupling takes place heterogeneously and dehydrogenation of ammonia borane in these conditions leads to the formation of polyborazylene via intermediates like e.g., B-(cyclodiborazanyl) amine-borane and borazine. Our main results are reported and discussed herein.

Rhus verniciflua Stokes Extract and Its Flavonoids Protect PC-12 Cells against H2O2-Induced Cytotoxicity

  • Nam, Tae Gyu;Lee, Bong Han;Choi, Hyo-Kyoung;Mansur, Ahmad Rois;Lee, Sang Gil;Kim, Dae-Ok
    • Journal of Microbiology and Biotechnology
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    • v.27 no.6
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    • pp.1090-1097
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    • 2017
  • Rhus verniciflua Stokes (RVS), an herbal medicine found in East Asia, was extracted and further fractionated to investigate its antioxidant capacity and neuroprotective effects. The RVS ethyl acetate (EtOAc) fraction had the highest level of total phenolics and antioxidant capacity among all solvent fractions tested. Pretreatment of PC-12 cells with the EtOAc fraction effectively attenuated $H_2O_2$-induced oxidative damage. Furthermore, the EtOAc fraction significantly attenuated caspase-3 activity, resulting in inhibition of $H_2O_2$-induced apoptosis. We identified and quantified fustin, sulfuretin, and butein in the EtOAc fraction using accurate mass quadrupole time-of-flight mass spectrometry and reversed-phase high-performance liquid chromatography. The intracellular antioxidant capacity and superoxide dismutase (SOD) activity were significantly increased in PC-12 cells treated with the EtOAc fraction and with individual flavonoids. When cells were pretreated with the EtOAc fraction or individual flavonoids and then co-incubated with diethyldithiocarbamic acid (an inhibitor of SOD activity), cell viability against $H_2O_2$-induced oxidative stress was attenuated. These results suggest that the RVS EtOAc fraction and its flavonoid constituents protect PC-12 cells against $H_2O_2$-induced neurotoxicity through their antioxidant properties.

Toxicity of PFCs in Embryos of the Oryzias latipes Using Flow though Exposure System (유수식 연속노출장비를 이용한 과불화화합물(PFOS, PFOA)이 송사리 (Oryzias latipes) 알의 초기발생과정에 미치는 영향 연구)

  • Cho, Jae-Gu;Kim, Kyung-Tae;Ryu, Tae-Kwon;Park, Yu-Ri;Yoon, Jun-Heon;Lee, Chul-Woo;Kim, Hyun-Mi;Choi, Kyung-Hee;Jung, Ki-Eun
    • Environmental Analysis Health and Toxicology
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    • v.25 no.2
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    • pp.145-151
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    • 2010
  • Perfluorinated chemicals (PFCs) is a kinds of persistent organic pollutants, and have the potential toxicity of which is causing great concern. In this study, we employed Oryzias latipes embryos to investigate the developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)s compound using flowthrow system for 14 day. O. latipes embryos were exposed to solvent control, 20, 40 and 80 mg/L of PFOS and 62.5, 130, 260 mg/L of PFOA respectively. After exposure, hatchability, mortality, total length and heart beats were examined. Hatching rates were reduced approximately 27% in the 80 mg/L PFOS-treated group and 17% in the 62.5, 130 mg/L PFOA-treated groups. Heart beats in the PFOS-treated groups were reduced at 7 day but, PFOA-treated groups were increased heart beats. 80 mg/L PFOS treated group showed significant reduction in growth (total length) level to 90% of control. But PFOA did not showed significant effect on growth. In the 14 days $LC_{50}$ of PFOS and PFOA was 22.74 mg/L and 173 mg/L, respectively. The overall results indicated that the early stage of O. latipes might be a reliable model for the testing of developmental toxicity to perfluorinated chemicals.

Effect of etoricoxib on experimental oxidative testicular ischemia-reperfusion damage in rats induced with torsion-detorsion

  • Yapanoglu, Turgut;Ozkaya, Fatih;Yilmaz, Ali Haydar;Mammadov, Renad;Cimen, Ferda Keskin;Hirik, Erkan;Altuner, Durdu
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.5
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    • pp.457-464
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    • 2017
  • Etoricoxib features antioxidant and anti-inflammatory properties concomitantly, suggesting that it may be beneficial in testicular ischemia reperfusion (I/R) damage. Our aim is to investigate the effects of etoricoxib on testicular I/R damage induced with torsion-detorsion (TD). The etoricoxib + torsion-detorsion (ETD) groups of animals were given etoricoxib in 50 and 100 mg/kg of body weight (ETD-50 and ETD-100), while the testes torsion-detorsion (TTD) and sham operation rat group (SOG) animals were given single oral doses of distilled water as a solvent. TTD, ETD-50 and ETD-100 groups were subjected to $720^{\circ}$ degrees torsion for four hours, and detorsion for four hours. The SOG group was not subjected to this procedure. Biochemical, gene expression and histopathological analyses were carried out on the testicular tissues. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta ($IL-1{\beta}$) and tumor necrosis factor alpha ($TNF-{\alpha}$) were significantly higher, and the levels of total glutathione (tGSH) and glutathione reductase (GSHRd) were significantly lower in the TTD group, compared to the ETD-50, ETD-100 and SOG groups. Etoricoxib at a dose of 100 mg/kg better prevented I/R damage than the 50 mg/kg dose. Etoricoxib may be useful in clinical practice in the reduction of I/R damage on testes caused by torsion-detorsion.