A simple, rapid and selective liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is developed and validated for quantification of venlafaxine in human plasma with simple liquid-liquid extraction step consisted of extraction with ether and dichloromethane for 10 min and mixing with 1 M sodium acetate in human plasma using fluoxetine as an internal standard (IS). The analyte are separated using an isocratic mobile phase consisted of acetonitrile and 5 mM ammonium formate (4/3, v/v) on a isocratic YMC hydrosphere C18 (2.0x50.0 mm, 3.0 microm) column and analyzed by MS/MS in the multiple reaction monitoring (MRM) mode using the transitions of respective [M+H](+) ions, m/z 278.2-->260.3 and m/z 310.1-->148.1 for quantification of venlafaxine and IS, respectively. The standard calibration curves showed good linearity within the range of 1.0-200.0 ng/mL (r2=0.9986, 1/chi2 weighting). The lower limit of quantification (LLOQ) was 1.0 ng/mL. The retention times of venlafaxine and IS were 0.6 min and 0.7 min that means the potential for the high-throughput potential of the proposed method. In addition, no significant metabolic compounds were found to interfere with the analysis. Acceptable precision and accuracy were obtained for the concentrations over the standard curve range. The validated method was successfully applied to bioequivalence study after 75-mg of venlafaxine sustained-release (SR) capsule in 24 healthy Korean subjects.
Ammonium Compounds ; Calibration ; Chromatography, Liquid ; Ether ; Fluoxetine ; Humans ; Ions ; Liquid-Liquid Extraction ; Methylene Chloride ; Pharmacokinetics ; Plasma* ; Sodium Acetate ; Tandem Mass Spectrometry ; Therapeutic Equivalency* ; Venlafaxine Hydrochloride

OBJECTIVEIn order to find a method for improving the salt resistance of seeds and seedlings for Perilla frutescens under NaCl stress, seed germination and physiological characteristics of P. frutescens seedlings were studied.

METHODSeveral physiological indexes of P. frutescens seeds treated by Ca2+ and sodium nitroprusside (SNP) under NaCl stress like the germination vigor, germination rate, germination index and vigor index were measured. And other indexes like the biomass of the seedlings, the content of malondialdehyde (MDA) in leaves, the activities of superoxide (SOD), peroxidase (POD) and catalase (CAT) were also measured.

RESULTThe germination of P. frutescens seeds under NaCl stress was inhibited obviously. But after the treatment with Ca2+ and SNP, all of the germination indexes increased. And the seeds that treated with SNP + Ca2+ had the most significantly increase in all indexes. The germination vigor was 65.1%, the germination rate was 89.3%, the germination index and vigor index were 13.9 and 0.1109, respectively. The content of MDA decreased after the treatment. The activities of three enzymes include SOD, POD and CAT were increased by the treatment and get the maximin 0.84, 5.71 and 4.92 U x mg(-1) respectively. And the EGTA showed an obvious inhibition to the effect of SNP on P. frutescens.

CONCLUSIONSNP (0.1 mmol x L(-1)) and Ca2+ (10 mmol x L(-1)) could significantly alleviate the damages to the seeds and seedlings of P. frutescens under NaCl stress, and promote the salt resistance of the seeds and seedlings. These results might suggest that exogenous NO might enhance P. frutescens salt resistance and alleviate salt injury possible by enhancing Ca2+ influx by activating Ca2+ channels and improving concentration of Ca2+ of P. frutescens seedlings.

Calcium ; pharmacology ; Catalase ; metabolism ; Germination ; drug effects ; Nitroprusside ; pharmacokinetics ; Perilla ; drug effects ; enzymology ; physiology ; Peroxidases ; metabolism ; Plant Proteins ; metabolism ; Seedlings ; drug effects ; enzymology ; metabolism ; physiology ; Sodium Chloride ; metabolism ; Stress, Physiological

Effects of intracellular Na+, K+ and Cl- on Ca(2+)-regulated exocytosis activated by 10 microM acetylcholine (ACh) were studied in guinea-pig antral mucous cells which are permeabilized by nystatin treatment. Ca(2+)-regulated exocytotic events were modulated by [Na+]i, [K+]i and [Cl-]i via mediation of PTX-sensitive G proteins. Increases in [Na+]i and PTX inhibit G protein (G(Na)), which suppressed the exocytosis. Increases in [K+]i caused the exchange of G proteins (from G(Na) to G(K)) to increase, and GK evoked activation of the exocytosis and was inhibited by PTX. Increases in [Cl-]i and PTX inhibit G protein (G(Cl)), which stimulates exocytotic events. Based on these observations, the exocytosis in antral mucous cells were modulated by intracellular ions, concentration of which were increased or decreased by cell volume changes caused by Ach.
Acetylcholine/pharmacology ; Animal ; Cell Membrane Permeability/drug effects ; Exocytosis/physiology* ; Exocytosis/drug effects ; Gastric Mucosa/metabolism ; Gastric Mucosa/cytology ; Guinea Pigs ; Hypertonic Solutions/pharmacology ; Ionophores/pharmacology ; Nystatin/pharmacology ; Pertussis Toxins/pharmacology ; Potassium/pharmacokinetics* ; Pyloric Antrum/metabolism* ; Pyloric Antrum/cytology ; Sodium Chloride/pharmacokinetics* ; Vasodilator Agents/pharmacology

The purpose of this study is to develop glipizide push-pull osmotic pump (PPOP) tablets by using a formulation design expert system and an artificial neural network (ANN). Firstly, the expert system for the formulation design of osmotic pump of poor water-soluble drug was employed to design the formulation of glipizide PPOP, taking the dissolution test results of Glucotrol XL as the goal. Then glipizide PPOP was prepared according to the designed formulations and the in vitro dissolution was carried out. And in vivo evaluation was carried out between the samples which were similar to Glucotrol XL and the Glucotrol XL in Beagle dogs. The range of the factors of formulation and procedure, which could influence the drug release, was optimized using artificial neural network. Finally, the design space was found. It was found that the target formulation which was similar to Glucotrol XL in dissolution test could be obtained in a short period by using the expert system. The samples which were similar to Glucotrol XL were bio-equivalent to the Glucotrol XL in Beagle dogs. The design space of the key parameter coating weight gain was 9.5%-12.0%. It could be concluded that a well controlled product of glipizide PPOP was developed since the dissolution test standard of our product was more strict than that of Glucotrol XL.
Animals ; Area Under Curve ; Delayed-Action Preparations ; Dogs ; Drug Compounding ; methods ; Drug Delivery Systems ; Drug Design ; Expert Systems ; Female ; Glipizide ; administration & dosage ; chemistry ; pharmacokinetics ; Hypoglycemic Agents ; administration & dosage ; chemistry ; pharmacokinetics ; Male ; Neural Networks (Computer) ; Osmosis ; Polyethylene Glycols ; chemistry ; Random Allocation ; Sodium Chloride ; chemistry ; Solubility ; Tablets

This study is to prepare the W/O microemulsion containing NaCl and fluorouracil (5-Fu) as a model drug to investigate the transdermal characteristics and skin irritation of the microemulsion in vitro. Isopropylmyristate (IPM) acting as oil phase, Aerosol-OT (AOT) as surfactant, Tween 85 as cosurfactant, NaCl solution was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, and then 5-Fu powder was added. According to the area of microemulsion based on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cells to study the influence of the amount of water and the drug loading capacity and optimize the formulation further. Refer to 5-Fu cream, the irritation of microemulsion on the rat skin was studied. The optimum formulation was composed of 0.7% (w/v) 5-Fu, 50% NaCl solution (0.05 mol x L(-1)), 20% mix-surfactant (AOT/Tween 85, K(m) = 2) and 29.3% oil (IPM). The cumulative amount of fluorouracil permeated in 12 h was (2 013.4 +/- 41.6) microg x cm(-2), 20.23 folds and 10.38 folds more than 0.7% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. Microemulsion exhibited some irritation, but could be reversed after drug withdrawal. The addition of NaCl significantly increased the content of water and the drug loading in microemulsion systems. The NaCl/AOT-Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.
Administration, Cutaneous ; Animals ; Antimetabolites, Antineoplastic ; administration & dosage ; adverse effects ; pharmacokinetics ; Dioctyl Sulfosuccinic Acid ; chemistry ; Drug Carriers ; Drug Delivery Systems ; Emulsions ; Exanthema ; chemically induced ; Fluorouracil ; administration & dosage ; adverse effects ; pharmacokinetics ; In Vitro Techniques ; Male ; Mice ; Myristates ; chemistry ; Oils ; chemistry ; Polysorbates ; chemistry ; Rats ; Rats, Sprague-Dawley ; Skin Absorption ; Sodium Chloride ; chemistry ; Surface-Active Agents ; chemistry ; Water