The stability of the antidepressive agent nomifensine in human plasma

1980 ◽  
Vol 32 (1) ◽  
pp. 304-305 ◽  
Author(s):  
S. DAWLING ◽  
R. BRAITHWAITE
Keyword(s):  
Human Plasma ◽  
The Stability ◽  
Antidepressive Agent

scholarly journals Validation of developed method by RP-HPLC for simultaneous estimation of famotidine and ibuprofen in human plasma and studying the stability of the drugs in plasma

2018 ◽  
Vol 12 (1) ◽  
pp. 34-48
Author(s):  
K. S Ashutosh ◽  
D. Manidipa ◽  
R. J. V. L. N. Seshagiri ◽  
S. D. Gowri
Keyword(s):  
Human Plasma ◽  
Mobile Phase ◽  
Simultaneous Estimation ◽  
Hplc Separation ◽  
Reverse Phase ◽  
Rp Hplc ◽  
The Stability ◽  
Sodium Dihydrogen ◽  
Isocratic Mode

The RP-HPLC separation was carried out by reverse phase chromatography on a Symmetry C18 (4.6 x 150 mm, 3.5 μm, make: XTerra) with a mobile phase composed of sodium dihydrogen ortho phosphate [pH 2.5] and acetonitrile in the ratio of 30:70 v/v in an isocratic mode at a flow rate of 1.2 mL/min. The run time was maintained for 8.0 min. The detection was monitored at 236 nm. The accuracy was calculated in human plasma and the % recovery was found 99.80 - 99.85 for famotidine and 99.56 -99.85.5 for ibuprofen and reproducibility was found to be satisfactory. The calibration curve for famotidine in human plasma was linear over 3.32 to 6.65 μg/mL and 100- 200 μg/mL for ibuprofen in human plasma respectively. The inter-day and intra-day precision in human plasma was found within limits. The proposed method has adequate sensitivity, reproducibility, and specificity for the determination of famotidine and ibuprofen in plasma. The LLOQ obtained by the proposed method in human plasma were 1.24 and 5.0 μg/mL for famotidine and ibuprofen respectively. The proposed method is simple, fast, accurate, and precise for the quantification of famotidine and ibuprofen in plasma as per the ICH guidelines.Kathmandu University Journal of Science, Engineering and TechnologyVol. 12, No. I, June, 2016, Page: 34-48

scholarly journals Validation of developed method by RP-HPLC for estimation of Prasugrelin human plasma and studying the stability of the drugs in plasma

2018 ◽  
Vol 13 (1) ◽  
pp. 65-75
Author(s):  
Kumar S. Ashutosh ◽  
Debnath Manidipa ◽  
Rao J.V.L.N. Seshagiri ◽  
Sankar D. Gowri
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Method Development ◽  
Potassium Dihydrogen Phosphate ◽  
Array Detector ◽  
Dihydrogen Phosphate ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Relative Standard ◽  
The Stability

This paper is concern with a reverse phase high performance liquid chromatography (RP-HPLC) bio-analytical method development and validation for Prasugrel in human plasma using photo diode array detector (PDA detector). The HPLC separation was carried out in an isocratic mode on an X-Terra C18 column (4.6 x 150 mm; 5 μm) with a mobile phase consisting of potassium dihydrogen phosphate [pH 3.0] and acetonitrile in the ratio of 30:70 v/v at a flow rate of 1.0 mL/min. The run time was maintained for 5 mins and the detection was monitored at 210 nm. The percentage recovery was found 99.61-100.06 in human plasma. This reveals that the method is quite accurate. The linearity was found 15-40 μg/mL in human plasma. The inter-day and intra-day precision in plasma was found within the limits. The lower limit of quantification (LLOQ) obtained by the proposed method was 0.05 μg/mL. The percentage relative standard deviation (%RSD) obtained for the drug spiked in plasma for stability studies were less than 2 %.Kathmandu University Journal of Science, Engineering and TechnologyVol. 13, No. 1, 2017, Page: 65-75

THE PROTECTIVE EFFECT OF ACYLATI0N ON THE STABILITY OF EMINASE (APSAC) IN HUMAN PLASMA

1987 ◽  
Author(s):  
R Fears ◽  
H Ferres ◽  
R Standring
Keyword(s):  
Protective Effect ◽  
Human Plasma ◽  
Fibrinolytic Activity ◽  
Animal Studies ◽  
Active Form ◽  
Α2 Macroglobulin ◽  
The Stability ◽  
High Level ◽  
Activator Complex

Clinical and animal studies indicate that APSAC (anisoylated plasminogen.streptokinase activator complex, Eminase) circulates longer in the bloodstream in an active form than the other thrombolytics. In the present studies in vitro u/e have found that functional activity of APSAC is maintained in human plasma longer than that of SK.plasmin(ogen): the relative stability half-lives are similar to the plasma clearance haif-lives in patients. Some of the loss of activity of SK at early times can be attributed to neutralisation by inhibitors. Thus, the survival of fibrinolytically-active SK was promoted in plasma depleted in α2-antiplasmin (α2AP) and α2AP-SK.plasmin complexes (detected by immunoblotting) formed rapidly in normal plasma. Corresponding studies with α2 macroglobulin-depleted plasma suggested a slight, late influence on SK activity but the inhibitor complex has not been detected unequivocally. In addition, loss of SK activity can be attributed, in part, to. rapid degradation to low molecular products. The degradation of SK in APSAC was much slower. In other comparative studies, the stability of APSAC was found to be similar to the stability of prourokinase and much superior to that of SK which is similar to UK; t-PA is intermediate in stability.Maintenance of fibrinolytic activity vivo depends on the stability of the thrombolytic, its rate of clearance and mode of administration. The protective effect of acylation, demonstrated in these experiments, explains why the objective of maintaining a high level of fibrinolytic activity after intravenous bolus injection of APSAC is less compromised by opposing inactivation processes.

Factors affecting the stability of tPA and PAI-1 during storage and handling of human plasma for in vitro studies

1990 ◽  
Vol 1 (5) ◽  
pp. 393-400 ◽  
Author(s):  
F. Hamon ◽  
C. Masson-Lunven ◽  
B. Boutiere ◽  
C. Boyer-Neumann ◽  
M. J. Larri??u ◽  
...  
Keyword(s):  
Human Plasma ◽  
In Vitro Studies ◽  
Factors Affecting ◽  
The Stability ◽  
Pai 1

scholarly journals Quantification of Cefepime, Meropenem, Piperacillin, and Tazobactam in Human Plasma Using a Sensitive and Robust Liquid Chromatography-Tandem Mass Spectrometry Method, Part 2: Stability Evaluation

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Ronilda D'Cunha ◽  
Thanh Bach ◽  
Beth Ann Young ◽  
Peizhi Li ◽  
Demet Nalbant ◽  
...  
Keyword(s):  
Human Plasma ◽  
Whole Blood ◽  
Room Temperature ◽  
Solution Stability ◽  
Short Term ◽  
Term Stability ◽  
Degradation Rates ◽  
Liquid Chromatography Tandem Mass ◽  
The Stability ◽  
Stability Results

ABSTRACT Although the stability of β-lactam antibiotics is a known issue, none of the previously reported bioanalytical methods had an adequate evaluation of the stability of these drugs. In the current study, the stability of cefepime, meropenem, piperacillin, and tazobactam under various conditions was comprehensively evaluated. The evaluated parameters included stock solution stability, short-term stability, long-term stability, freeze-thaw stability, processed sample stability, and whole-blood stability. When stored at −20°C, the stock solution of meropenem in methanol was stable for up to 3 weeks, and the stock solutions of cefepime, piperacillin, and tazobactam were stable for up to 6 weeks. All four antibiotics were stable in human plasma for up to 3 months when stored at −80°C and were stable in whole blood for up to 4 h at room temperature. Short-term stability results indicated that all four β-lactams were stable at room temperature for 2 h, but substantial degradation was observed when the plasma samples were stored at room temperature for 24 h, with the degradation rates for cefepime, meropenem, piperacillin, and tazobactam being 30.1%, 75.6%, 49.0%, and 37.7%, respectively. Because the stability information is method independent, our stability results can be used as a reference by other research groups that work with these antibiotics.

scholarly journals Long-Term Storage Effects on Stability of Aβ1–40, Aβ1–42, and Total Tau Proteins in Human Plasma Samples Measured with Immunomagnetic Reduction Assays

2019 ◽  
Vol 9 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Ming-Jang Chiu ◽  
Lih-Fen Lue ◽  
Marwan N. Sabbagh ◽  
Ta-Fu Chen ◽  
H.H. Chen ◽  
...  
Keyword(s):  
Human Plasma ◽  
Plasma Levels ◽  
Plasma Samples ◽  
Total Tau ◽  
Long Term Storage ◽  
Human Plasma Samples ◽  
The Stability ◽  
T Tau ◽  
Term Storage

Background: The stability of Alzheimer’s disease (AD) biomarkers in plasma, measured by immunomagnetic reduction (IMR) after long-term storage at –80°C, has not been established before. Method: Ninety-nine human plasma samples from 53 normal controls (NCs), 5 patients with amnestic mild cognitive impairment (aMCI), and 41 AD patients were collected. Each plasma sample was aliquoted and stored as single-use aliquots at –80°C. The baseline measurements for Aβ1–40, Aβ1–42, and total Tau protein (T-Tau) concentrations for each sample were done within 3 months of blood draw by IMR. They are referred to as baseline concentrations. A separate aliquot from each sample was assayed with IMR to assess the stability of the measured analytes during storage at –80°C between 1.1 and 5.4 years. This is referred to as a repeated result. Results: IMR shows that plasma levels of Aβ1–40 and Aβ1–42 exhibit stability over 5-year storage at –80°C and that plasma levels of T-Tau are less stable (approximately 1.5 years). Conclusion: Although the measured concentrations of T-Tau in human plasma may alter during storage, the diagnostic utility of the results are only slightly affected when the product of Aβ1–42 and T-Tau concentrations are used. The results show that the overall agreement between baseline and repeated measurements in the ability of discriminating NCs from aMCI/AD patients is higher than 80%.

Cholinesterase Inhibition Autoanalysis of Insecticidal Organophosphates and Carbamates

1969 ◽  
Vol 52 (5) ◽  
pp. 1027-1034
Author(s):  
Günther Voss
Keyword(s):  
Human Plasma ◽  
Lower Limit ◽  
Cholinesterase Inhibition ◽  
Timing Behavior ◽  
Chemical Methods ◽  
Simultaneous Inhibition ◽  
The Stability ◽  
Inhibition Potency ◽  
Better Than

Abstract An automated cholinesterase inhibition method gave satisfactory results during the development of insecticidal organophosphates and carbamates. Up to 40 samples/hr were analyzed with a precision equal to that of purely chemical methods performed manually. The lower limit of detectability of the method depends primarily on the inhibition potency of the particular compound under investigation and upon whether the system is operated in a pre-inhibition (most sensitive) or simultaneous inhibition (least sensitive) mode. Monocrotophos, for example, was analyzed in the concentration ranges of 0.1–2.0, 1–20, 10–200, and 100–2000 ppm; the last two concentration ranges were analyzed in the simultaneous inhibition mode. Sensitivities better than those achieved with human plasma :holinesterase, i.e., 0.1 ppm for monocroophos, were obtained by using a more sensiive type of cholinesterase, such as peacock ilasma cholinesterase. Examples of experinents, such as determinations of the stability if formulations, rates of hydrolysis, parti timing behavior of insecticides, solubilities in vatcr, and the determination of a cholineserase-inhibiting impurity in a technical samde of phosphamidon, are also described and locumented by original AutoAnalyzer reordings.

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