جستجوی مقالات مرتبط با کلیدواژه « human plasma » در نشریات گروه « شیمی »

Embelin is the main bioactive chemical in E. ribes berries and possesses various biological properties. Currently, no liquid chromatographic method is available for quantitative estimation of embelin from human plasma. The purpose of this study was to develop an accurate, precise, and simple reverse-phase high-performance liquid chromatographic method for measuring the amount of embelin in human plasma. The separation of embelin was achieved using a Waters C18 (150 x 4.6 mm i.d., 5µ particle size) column. A mixture of acetonitrile and phosphate buffer whose pH was adjusted to 3.6 in a 20:80 v/v ratio and at a flow rate of 1.4 ml/min was employed as a mobile phase. The detection was performed at 289 nm. The plasma extraction method was validated for various parameters, including precision, accuracy, and stability.The developed method using human plasma was linear over a range of 13.9–41.65 ng/µl concentrations with a regression coefficient of 0.984. The accuracy testing revealed the value of the mean percent recovery between 101.54 and 109.15. The mean intra- and inter-day precision of the assay ranged from 105.04 to 91.16% and 0.3628 to 1.4227% RSD, respectively. The extracted samples also showed bench-top and freeze-thaw stability over 72 hours. In human plasma, embelin was found to be stable. The method's validation parameters satisfied the required criteria for acceptance. From the results, we concluded that the developed method can be used for accurate and precise quantification of embelin from human plasma.

Cultivated media for the growth of human blood cells are many, but the use of natural and less expensive materials is the most important to obtain the suitable growth for the cultivation of human lymphocytes. It needs a lot of materials that help in its development. Here, plasma is a very important growth factor for the growth of cells, which through its growth is useful in studying many natural and abnormal processes and interactions that occur in cells or studying the effect of many chemicals on cells through the examination of cell division so that it does not affect the nature of their chromosomes, and the results showed that the best concentration of chromosomes. Human plasma suitable for the growth of human blood cells is 20% and 10% plasma concentration which gave the highest cell division rate that could be obtained. There are no significant differences between plasma concerning the cell division index. As for the study of the chromosomal body, this indicator is important and is widely used in cytogenetic studies.

Ultrasound-assisted  emulsification  microextraction  (USAEME)  and  gas  chromatography – flame ionization detection (GC-FID) was presented for the extraction and determination of olanzapine in human urine and plasma samples. Chlorobenzene at microliter volume level as an extraction solvent without  disperser  solvent  was  used.  The  main advantages  of  this  method  are  high  speed,  high recovery,  good  repeatability  and  extraction  solvent  volume  at  µL  level.  The  effect  of  several variables such as type and volume of extraction solvent, ultrasonication time, centrifugation time, salt addition, etc. were evaluated, carefully. In the optimum conditions, the calibration curve was linear in the range of 70-2000 µg L-1 with the detection limit of 20 µg L-1. The relative standard deviation  (R.S.D.)  for  the  five  replicate  measurements  of  olanzapine  was  4.6  %.  USAEME combined with GC-FID is a fast, simple and efficient method for the determination of olanzapine in human urine and plasma samples.

In this study, a dispersive liquid–liquid microextraction method using an extraction solvent lighter than water has been developed for the extraction and preconcentration of cholecalciferol and calcifediol from plasma samples followed by high performance liquid chromatography determination. Initially, acetonitrile and sodium chloride (NaCl) are added into the plasma as an extraction solvent and a salting–out agent, respectively. After manual shaking, the mixture is centrifuged. In the presence of sodium chloride, a two–phase system is formed. Then a portion of the upper phase is removed and mixed with n–hexane at µL–level and rapidly injected into distilled water by a syringe. In this process, the analytes are extracted into the fine droplets of n–hexane (as an extraction solvent). Under optimal conditions, enrichment factor was obtained 92 and 94 for calcifediol and cholecalciferol, respectively. The intra– (n=6) and inter–day (n=4) precisions were less than or equal to 8.1% at a concentration of 10 ng mL–1 of each analyte. Finally, this method was applied to the analysis of the analytes in human plasma samples.

For the first time, a novel and efficient ionic liquid-based ultrasound-assisted in-situ solvent formation microextraction (IL-UA-ISFME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) has been successfully developed for the determination of duloxetine (DLX) in human plasma. Herein, an environmentally-friendly hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was formed by addition of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) to sample solution including NaPF6 as an ion-pairing agent. The analyte was extracted into the ionic liquid although the microextraction solvent was dispersed among the sample solution using ultrasound radiation. The sample was then centrifuged and extracting phase injected into HPLC system. The developed sample enrichment method revealed considerable robustness against the variations of sample ionic strength. Begin with, parameters controlling the performance of the microextraction were evaluated and optimized. The limit of detection was 0.8 µg L-1 while a good linearity (r2 = 0.996) and a broad linear range (2.0 to 1500 µg L-1) were achieved. A reasonable relative recoveries (83.6-92.1%) and appropriate intra-assay (4.0-5.1%, n = 5) and inter-assay (4.3-7.6%, n = 9) precisions along with appropriate sample clean-up exhibited good performance of the analytical procedure. It was eventually validated for the screening purposes in human plasma after oral administration of the drug and some pharmacokinetic data were achieved. This green method is prompt, convenient, and reliable and offers satisfactory reproducibility as well as sufficient sensitivity.

A simple, accurate and fast vortex-assisted dispersive liquid-liquid microextraction procedure has been developed for the extractive spectrophotometric determination of niflumic acid in biological samples. The method is based on the formation of an ion association complex between niflumic acid and methylene blue. The resulting ion-pair was extracted into dichloromethane and its absorbance was measured at 655 nm. All experimental parameters affecting the analytical performance of the method such as pH, type and volume of buffer and extraction solvent, dye concentration, extraction time, ionic strength and interfering species were investigated. The calibration curve was linear in the range of 5-70 ng mL-1 and the limit of detection (LOD) was found to be 2.8 ng mL-1. The procedure was successfully applied for the determination of niflumic acid in human plasma and goat’s milk samples. The main advantages of the proposed method are rapidity, little solvent consumption, low cost and providing low LOD by the simple UV-Vis spectrophotometer.

Quetiapine fumarate is a dibenzothiazepine derivative and it is classified as a second-generation antipsychotic drug that has been established as an effective therapy for schizophrenia and bipolar disorder. These antipsychotics have a low incidence of extrapyramidal side effects and tardive dyskinesi as compared to older antipsychotics. The advantages of the therapeutic profile of quetiapine have led to increasing the use of the clinical practice encouraging the development of new pharmaceutical preparations.

The goal of this work was to recognize the synthesis and analytical deference methods of quetiapine fumarate.

Generally, A precise, specific, rapid and feasible reversed-phase high-performance liquid chromatographic (RP-HPLC), UV spectrophotometric and reversed phase ultra-performance liquid chromatography (RP-UPLC) methods for the determination of an antipsychotic drug quetiapine fumarate in pharmaceuticals, spiked human urine and plasma sample have been developed and collected in this review. The methods also find applications in clinical, biological and pharmacokinetic studies of quetiapine fumarate.

The present study describes a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of S-RRR and R-SSS nebivolol (nebivolol enantiomers) in human plasma using solid phase extraction technique. Method of both S-RRR and R-SSS nebivolol (nebivolol enantiomers) has been developed and validated using racemic nebivolol D4 as an internal standard. Analytes from human plasma were extracted by ion exchange cartridges and subsequently separated on chiral column using acetonitrile: ammonium carbonate in water, 158 mg/L 80:20% v/v as a mobile phase, at a flow rate of 0.9 mL/min. Quantification of S-RRR and R-SSS nebivolol and R-nebivolol D4 was performed using multi-reaction monitoring mode (MRM) in positive mode. The calibration curve was linear (r2 > 0.99) over the concentration range of 20.0 to 6000 pg/mL for S-RRR and R-SSS nebivolol. The intra-day and inter-day assay precision revealed within ±15% (at LLOQ level ±20%) with accuracy within 85%-115% (at LLOQ level 80% -120%). The LC-MS/MS method was fully validated for all the validation parameters as per current regulatory requirement (US FDA, EU) such as selectivity, matrix effect, recovery and stability (in solution and in matrix stability).

A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via solid phase extraction and the chromatographic separation was achieved on Inertsil ODS-3, 50 x 4.6 mm, 5µ column under isocratic conditions. Detection of CA and IS was done by tandem mass spectrometry, operating in positive ionization and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for CA and IS were m/z 365.2→240.2 and 409.2→228.2, respectively. The method was fully validated as per the US FDA guidelines. The linear dynamic range of CA was 7.564 - 897.893 ng/mL. The intra-batch and inter-batch precision (%CV) was ≤ 14.1% while the mean extraction recovery was 84.48 % across quality control levels. It was successfully applied to a bioequivalence study of Cefdinir/CA (125 mg/62.5 mg) suspension formulation in 32 healthy Indian male subjects under fasting condition.

Recent clinical and pre-clinical data demonstrate that adjuvant antimicrobial therapy is beneficial in cancer treatment. For the first time, an electrochemical method was proposed for the simultaneous determination of acyclovir (ACV) and methotrexate (MTX) at activated or electropretreated pencil graphite electrode (EPPEG). Their simultaneous determination was achieved by cyclic voltammetry (CV) and adsorptive square wave voltammetry (AdSWV) techniques. The proposed sensor has a wide linear range of 2×10 -7 to 1.4×10 -6 M for MTX and 5×10 -7 to 3×10 -6 M for ACV. The limits of detection (LOD) values were found 1.13×10-8 M and 6.07×10-8 M for MTX and ACV, respectively. The proposed method was applied in their pharmaceutical formulations and human plasma. In addition the proposed method could be applied in pharmaceutical laboratories and quality control analysis in the near future.

A simple and sensitive chemiluminescence-based method was established for the determination of rabeprazole.The proposed method was based on the enhancing effect of rabeprazole on Ce(IV)-Na2SO3 -Tb(III) chemiluminescence reaction. A possible mechanism was discussed for chemiluminescence system by studying UV-Vis, fluorescence and chemiluminescence spectra. The effects of various chemical parameters were investigated and optimized. Under the optimum conditions, the enhanced chemiluminescence intensity was directly proportional to the concentration of rabeprazole in the range of 0.015-0.2 µg ml-1, with a detection limit of 6 ng ml-1. The proposed method was applied to the analysis of pharmaceutical formulations and human plasma samples and to the dissolution study of rabeprazole tablets with satisfactory results. The results indicated that more than 95% of the labeled amount of rabeprazole was dissolved over 30 min in the basic medium, while only 10% of rabeprazole was released in acidic medium.

Membrane selective electrodes were used to determine tetryzoline hydrochloride (TZH) in pure form, pharmaceutical preparations and in biological fluids. The membrane selective electrodes include construction of water insoluble ion-association complexes. The TZH ion exchangers were formed using tetraphenyl borate (TZH-TPB), phosphomolybdic acid (TZH-PMA) and phosphotungstic acid (TZH-PTA), in a plasticized PVC (polyvinyl chloride) matrix, using dibutyl phthalate (DBP) or dioctylphthalate (DOP) as a plasticizer. The performance characteristics of the developed sensors were evaluated according to IUPAC recommendations. The developed sensors showed good responses but the best electrochemical characteristics and selectivity coefficients were achieved with TZH-TPB sensor using DBP as a plasticizer, where the linear responses of TZH was found within the concentration ranges of 10−6 to 10−2 mol/L and Nernstian slope was calculated to be of 56.8 mV/ decade at 25 °C, over the pH range of 5–9. The suggested method was used to determine TZH in synthetic mixtures, pharmaceutical formulations and in presence of its alkali degradation product. The proposed sensors displayed useful analytical characteristics for the determination of TZH in biological fluids such as rabbit aqueous humor and human plasma. The later application can be used to detect oral TZH poisoning in children. The obtained results were statistically compared with the official method, showing no significant difference with respect to accuracy and precision.