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1.
J Nanosci Nanotechnol ; 19(3): 1824-1828, 2019 Mar 01.
Article in English | MEDLINE | ID: mdl-30469275

ABSTRACT

Poly(vinylidene fluoride) (PVDF) is one of the most studied polymers that exhibits piezoelectric and ferroelectric properties. PVDF crystallizes into four different forms, namely α, ß, γ, and δ phases. Generally, the nonpolar α phase, as a replacement for the polar ß phase with the most superior ferroelectric and piezoelectric properties, is formed from the precursor melt and solution. Here, we report a method for the preparation of ß-phase-dominant PVDF thin films by doping PVDF solution with a metal hydrated salt, such as Co(NO3)2·6H2O, without any stretching procedure. The crystal structure of the film was analyzed using X-ray diffraction -2 scanning and Fourier transform infrared spectroscopy. The morphology of the film was observed using a field emission-scanning electron microscope. To determine the frequency dependence of dielectric properties, an LCR meter was used in the range of 50 Hz to 1 MHz. The crystalline phase and morphology of the electrostatic spray-deposited PVDF films depended on the chemical additive. Our results show that the addition of a metal hydrated salt can induce an in situ poling effect, consequently facilitating the preferred dipole orientation in the electrostatically sprayed PVDF films.

2.
Chem Pharm Bull (Tokyo) ; 59(5): 529-35, 2011.
Article in English | MEDLINE | ID: mdl-21532187

ABSTRACT

In order to develop a preferable once-a-day oral tablet formulation, various formulations of three-layered tablets containing tamsulosin HCl as a hydrophilic model drug were evaluated and compared with a commercial reference, tamsulosin OCAS®. When the test tablet was exposed to a release medium, the medium quickly permeated to the mid-layer and the two barrier layers swelled surrounding the mid-layer rapidly. Volume expansion showed faster and enough swelling of the three-layered tablet up to 2 h. Larger amount of barrier layers caused reduced release kinetics and a high molecular weight polymer showed more resistance against agitation force. A formulation with water-soluble mid-layer showed fast erosion decreasing its volume significantly. On the pharmacokinetic study, the mean ratio of area under the curve (AUC) and C(max) for the test formulation to the reference was 0.69 and 0.84, respectively, showing that the absorption of the drug was less complete than the reference. Plasma concentration at 24 h of the test formulation was higher than the reference. The Wagner-Nelson method showed that decreased initial dissolution rate might be the cause of the less complete absorption. On considering in vitro-in vivo correlation (IVIVC), level A, the reference (R²=0.981) showed more linear relationship than the test (R²=0.918) due to the decreased dissolution and absorption rate of the formulation. This result suggests that the in vitro dissolution profiles and release kinetics might be useful in correlating absorption kinetics as well as overall plasma drug concentration-time profiles for formulation studies.


Subject(s)
Adrenergic alpha-1 Receptor Antagonists/administration & dosage , Adrenergic alpha-1 Receptor Antagonists/pharmacokinetics , Chemistry, Pharmaceutical/methods , Sulfonamides/administration & dosage , Sulfonamides/pharmacokinetics , Adrenergic alpha-1 Receptor Antagonists/chemistry , Animals , Area Under Curve , Delayed-Action Preparations , Dogs , Drug Administration Schedule , Molecular Weight , Solubility , Sulfonamides/chemistry , Tablets/administration & dosage , Tablets/chemistry , Tablets/pharmacokinetics , Tamsulosin , Time Factors
3.
Biomed Chromatogr ; 24(10): 1031-7, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20099369

ABSTRACT

We describe a simple, rapid and sensitive high-performance liquid chromatography-electrospray ionization tandem mass spectrometric method that was developed for the simultaneous determination of carebastine and pseudoephedrine in human plasma using cisapride as an internal standard. Acquisition was performed in multiple-reaction monitoring mode by monitoring the transitions: m/z 500.43 > 167.09 for carebastine and m/z 166.04 > 147.88 for pseudoephedrine. The devised method involves a simple single-step liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a C(18) reversed-phase chromatographic column at 0.2 mL/min by isocratic elution with 10 mM ammonium formate buffer-acetonitrile (30:70, v/v; adjusted to pH 3.3 with formic acid). The devised method was validated over 0.5-100 ng/mL of carebastine and 5-1000 ng/mL of pseudoephedrine with acceptable accuracy and precision, and was successfully applied to a bioequivalence study involving a single oral dose (10 mg of ebastine plus 120 mg of pseudoephedrine complex) to healthy Korean volunteers.


Subject(s)
Butyrophenones/blood , Chromatography, High Pressure Liquid/methods , Piperidines/blood , Pseudoephedrine/blood , Spectrometry, Mass, Electrospray Ionization/methods , Butyrophenones/chemistry , Butyrophenones/pharmacokinetics , Cisapride/analysis , Cisapride/chemistry , Cross-Over Studies , Humans , Hydrogen-Ion Concentration , Male , Piperidines/chemistry , Piperidines/pharmacokinetics , Pseudoephedrine/chemistry , Pseudoephedrine/pharmacokinetics , Reproducibility of Results , Republic of Korea , Sensitivity and Specificity , Therapeutic Equivalency , Young Adult
4.
Life Sci ; 83(21-22): 700-8, 2008 Nov 21.
Article in English | MEDLINE | ID: mdl-18845169

ABSTRACT

AIMS: The resistance to chemotherapeutic drugs is a major problem for successful cancer treatment. Multidrug resistance (MDR) phenotype is characterized by over-expression of P-glycoprotein (P-gp) on the cancer cell plasma membrane that extrudes drugs out of the cells. Therefore, novel MDR reversal agents are desirable for combination therapy to reduce MDR and enhance anti-tumor activity. Thus, the present study was aimed to evaluate the potent efficacy of novel quinoline derivative KB3-1 as a potent MDR-reversing agent for combined therapy with TAX. MAIN METHODS: MDR reversing effect and TAX combined therapy were examined by Rhodamine accumulation and efflux assay and Confocal immunofluorescence microscopy, Western blotting, TUNEL assay, and cell cycle analysis. KEY FINDINGS: The discovery of quinoline-3-carboxylic acid [4-(2-[benzyl-3[-(3,4-dimethoxy-phenyl)-propionyl]-amino]-ethyl)-phenyl]-amide (KB3-1) as a novel MDR-reversal agent. KB3-1 significantly enhanced the accumulation and retention of a P-gp substrate, rhodamine-123 in the P-gp-expressing MES-SA/DX5 uterine sarcoma cells but not in the P-gp-negative MES-SA cells at non-toxic concentrations of 1 microM and 3 microM. Similarly, fluorescence microscopy observation revealed that KB3-1 reduced the effluxed rhodamine-123 expression on the membrane of MES-SA/DX5 cells. Consistent with decreased P-gp pumping activity, confocal microscopic observation revealed that KB3-1 effectively diminished the expression of P-gp in paclitaxel (TAX)-treated MES-SA/DX-5 cells. Furthermore, Western blotting confirmed that KB3-1 reduced P-gp expression and enhanced cytochrome C release and Bax expression in TAX treated MES-SA/DX-5 cells. In addition, KB3-1 enhanced TAX-induced apoptotic bodies in MES-SA/DX5 cells by TdT-mediated-dUTP nick-end labeling (TUNEL) staining assay aswell as potentiated TAX- induced cytotoxicity, G2/M phase arrest and sub-G1 apoptosis in MES-SA/DX5 cells but not in MES-SA cells. Interestingly, KB3-1 at 3 microM had comparable MDR-reversal activity to 10 microM verapamil, a well-known MDR- reversal agent. SIGNIFICANCE: KB3-1 can be a MDR-reversal drug candidate for combination chemotherapy with TAX.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents/pharmacology , Cell Cycle/drug effects , Drug Resistance, Multiple/drug effects , Drug Resistance, Neoplasm/drug effects , Paclitaxel/pharmacology , Quinolines/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Blotting, Western , Cell Line, Tumor , Cell Survival/drug effects , Cytochromes c/metabolism , Drug Synergism , Humans , In Situ Nick-End Labeling , Indicators and Reagents , Microscopy, Confocal , Microscopy, Fluorescence , Rhodamine 123 , bcl-2-Associated X Protein/metabolism
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