scholarly journals Spectrophotometric Determination of the Aggregation Activity of Platelets in Platelet-Rich Plasma for Better Quality Control

2019 ◽  
Vol 7 (2) ◽  
pp. 61 ◽  
Author(s):  
Tetsuhiro Tsujino ◽  
Kazushige Isobe ◽  
Hideo Kawabata ◽  
Hachidai Aizawa ◽  
Sadahiro Yamaguchi ◽  
...  
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Platelet Rich Plasma ◽  
Antiplatelet Agent ◽  
Adenosine Diphosphate ◽  
Buffer Solution ◽  
Platelet Concentration ◽  
Aggregation Activity ◽  
Induced Aggregation

Although platelet-rich plasma (PRP) is now widely used in regenerative medicine and dentistry, contradictory clinical outcomes have often been obtained. To minimize such differences and to obtain high quality evidence from clinical studies, the PRP preparation protocol needs to be standardized. In addition, emphasis must be placed on quality control. Following our previous spectrophotometric method of platelet counting, in this study, another simple and convenient spectrophotometric method to determine platelet aggregation activity has been developed. Citrated blood samples were collected from healthy donors and used. After centrifugation twice, platelets were suspended in phosphate buffered saline (PBS) and adenosine diphosphate (ADP)-induced aggregation was determined using a spectrophotometer at 615 nm. For validation, platelets pretreated with aspirin, an antiplatelet agent, or hydrogen peroxide (H2O2), an oxidative stress-inducing agent, were also analyzed. Optimal platelet concentration, assay buffer solution, and representative time point for determination of aggregation were found to be 50–100 × 104/μL, PBS, and 3 min after stimulation, respectively. Suppressed or injured platelets showed a significantly lower aggregation response to ADP. Therefore, it suggests that this spectrophotometric method may be useful in quick chair-side evaluation of individual PRP quality.

UV spectroscopic method for determination of phenytoin in bulk and injection forms

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Ich Guidelines ◽  
Precision And Accuracy ◽  
Routine Quality Control

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.

scholarly journals New Spectrophotometric Method for Determination of Cadmium

2009 ◽  
Vol 6 (s1) ◽  
pp. S496-S500
Author(s):  
K. S. Parikh ◽  
R. M. Patel ◽  
K. N. Patel
Keyword(s):  
Stability Constant ◽  
Spectrophotometric Method ◽  
Basic Medium ◽  
Buffer Solution ◽  
Solution Ph ◽  
Yellow Colour ◽  
Maximum Absorbance ◽  
The Stability

The reagent 2-hydroxy-4-n-butoxy-5-bromopropiophenone thiosemicarbazone (HBBrPT) has been used for the determination of Cd(II) by using spectrophotometric method. The reagent HBBrPT gave an intense yellow colour with Cd(II) solution in basic medium. The maximum absorbance was observed at 440 nm, in basic buffer solution (pH 10.00). The molor absorptivity and Sandell’s sensitivity of Cd(II)-HBBrPT complex were 4035 mol-1cm-1and 0.02765 μg cm-2respectively. The stability constant of 1:2 Cd(II)-HBBrPT complex was 8.46×106. The effect of various iron was also studied.

scholarly journals Use of platelet-rich plasma in regenerative medicine: technical tools for correct quality control

2018 ◽  
Vol 4 (1) ◽  
pp. e000442 ◽  
Author(s):  
Hajer Graiet ◽  
Anna Lokchine ◽  
Pauline Francois ◽  
Melanie Velier ◽  
Fanny Grimaud ◽  
...  
Keyword(s):  
Quality Control ◽  
Whole Blood ◽  
Sports Medicine ◽  
Platelet Rich Plasma ◽  
Systematic Sampling ◽  
Significant Difference ◽  
Platelet Concentration ◽  
Harvesting Method ◽  
Clinical Interest ◽  
The Subject

Background/aimsPlatelet-rich plasma (PRP) injections are used in sports medicine and have been the subject of increased clinical interest. However, there have been very few reports of the composition of initial whole blood and the final PRP product. The objective of this study was to provide technical tools to perform a correct characterisation of platelets, leucocytes and red blood cells (RBCs) from whole blood and PRP.MethodsBlood and PRP were obtained from 26 healthy volunteers and prepared according to the varying parameters encountered within PRP process preparation and quantification (harvesting method, anticoagulant used, sampling method, counting method). Concentrations were measured at t=0, t=1, t=6 and t=24 hours.ResultsSampling of blood in Eppendorf tubes significantly decreased platelet concentration over time, whereas sampling in Microvette EDTA-coated tube kept platelet concentration stable until 24 hours. A non-significant difference was observed in platelet counts in PRP with impedance (median (IQR): 521.8 G/L (505.3–524.7)) and fluorescence (591.5 G/L (581.5–595.8)) methods. Other studied parameters did not influence platelet concentrations in blood or PRP samples. Leucocytes and RBC counts were similar whatever the anticoagulant, sampling, harvesting and counting methods used for both blood and PRP samples.ConclusionsSystematic sampling of blood and PRP in EDTA-coated tubes for quality control is recommended. The use of a validated counter for PRP sample should also be taken into account.

scholarly journals Impaired platelet response to thromboxane-A2 and defective calcium mobilization in a patient with a bleeding disorder

Blood ◽  
1981 ◽  
Vol 57 (3) ◽  
pp. 545-552 ◽  
Author(s):  
B Lages ◽  
C Malmsten ◽  
HJ Weiss ◽  
B Samuelsson
Keyword(s):  
Platelet Rich Plasma ◽  
Calcium Ionophore ◽  
Thromboxane A2 ◽  
Adenosine Diphosphate ◽  
Bleeding Disorder ◽  
Ionophore A23187 ◽  
Platelet Response ◽  
Thromboxane Synthetase ◽  
Defect Aggregation ◽  
Induced Aggregation

Abstract Platelet aggregation, secretion, and thromboxane formation induced by various agonists, including arachidonate, prostaglandin-G2 (PGG2), and thromboxane-A2 (TxA2), were examined in a patient with a bleeding disorder who was previously reported to have a TxA2-related defect. Aggregation and 14C-5HT secretion were decreased, and no TxB2 formation occurred in response to adenosine diphosphate (ADP), epinephrine, or collagen. Arachidonate-induced aggregation and TxB2 formation, and PGG2- induced aggregation (but not TxB2 formation) were impaired at low agonist concentrations. The patient's platelets did not aggregate in response to TxA2 generated from arachidonate in normal platelets, but were capable of synthesizing TxA2 from both arachidonate and PGG2. In addition, aggregation and secretion induced by low concentrations of the ionophore A23187 were impaired in platelet-rich plasma (PRP) and in gel-filtered platelets in the absence of extracellular calcium; these responses became normal at higher A23187 concentrations or, in GFP, at low A23187 concentrations in the presence of exogenous calcium. These findings indicate that the TxA2 defect in this patient does not result from a thromboxane synthetase deficiency, but may be due to impaired mobilization of platelet calcium, and thus are consistent with the possibility that TxA2 may act as a calcium ionophore.

scholarly journals Microanalysis of Selected NSAIDs Using the Spectrophotometric Method

Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 211-221
Author(s):  
Paweł Gumułka ◽  
Monika Dąbrowska ◽  
Małgorzata Starek
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Pharmacokinetic Studies ◽  
Over The Counter ◽  
Nsaid Group ◽  
Inflammatory Drugs ◽  
Drug Quality Control ◽  
Uv Range

Non-steroidal anti-inflammatory drugs (NSAIDs) are the group of drugs most commonly used in medicine. They are available over the counter to treat fevers and pains of various origins. The clinical and pharmaceutical analysis of these drugs requires effective analytical procedures for drug quality control, pharmacodynamic and pharmacokinetic studies. This article presents the spectrophotometric method that was used to analyze selected drugs from the NSAID group. The conditions for the determination of selected coxibs and oxicams in the UV range with the use of microplates have been developed. The presented procedure has been validated in accordance with the requirements, guaranteeing reliable results. The obtained results give the basis for the conclusion that the method can be successfully used in the quality control of pharmaceutical preparations with a small amount of available sample.

Inhibition and potentiation of platelet function by lysolecithin

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 101-112 ◽  
Author(s):  
JH Joist ◽  
G Dolezel ◽  
MP Cucuianu ◽  
EE Nishizawa ◽  
JF Mustard
Keyword(s):  
Platelet Function ◽  
Platelet Rich Plasma ◽  
Membrane Damage ◽  
Adenosine Diphosphate ◽  
Lactic Dehydrogenase ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Serotonin Release ◽  
Prolonged Incubation ◽  
Induced Aggregation

Abstract The effects of lysolecithin (LPC) on aggregation, serotonin release, shape, and lysis of rabbit, pig, or human platelets in platelet-rich plasma (PRP) or Tyrode albumin solution were examined during prolonged incubation. LPC added to citrated or heparinized PRP from humans or rabbits at a final concentration above 100 muM caused instantaneous inhibition of platelet aggregation induced by adenosine diphosphate (ADP), epinephrine (human PRP only), collagen, or thrombin. The inhibitory effect of LPC was found to be partially reversible over a period of 60–90 min. LPC at final concentrations above 30 muM also caused inhibition of ADP-, collagen-, and thrombin-induced aggregation and collagen- and thrombin-induced release of serotonin in suspensions of rabbit, pig, or human platelets. With washed platelets, the inhibitory effect not only rapidly disappeared but was followed by transient potentiation of aggregation and serotonin release. This potentiating effect of LPC was most pronounced when thrombin was used as stimulus. Both inhibition and potentiation were observed at concentrations of LPC that did not cause a significant change in platelet shape or loss from platelets of lactic dehydrogenase. Inhibition and potentiation were also observed when platelets were added to suspending medium containing LPC, although considerably higher concentrations of LPC were required under these conditions. Potentiation was not observed when LPC was added to citrated or heparinized rabbit or human PRP or to washed rabbit platelets suspended in a medium containing 4% bovine serum albumin. It seemed likely that some or all of the observed effects of LPC on platelet function were due to structural modification of the platelet membrane insufficient to result in gross membrane damage or platelet lysis. In addition, the results of experiments using 14C-LPC seemed to indicate that the observed potentiating effect of LPC on platelet function may be related to its rapid uptake and metabolism by the platelets.

scholarly journals Zinc-induced platelet aggregation is mediated by the fibrinogen receptor and is not accompanied by release or by thromboxane synthesis

Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 213-219 ◽  
Author(s):  
P Heyns A du ◽  
A Eldor ◽  
R Yarom ◽  
G Marx
Keyword(s):  
Platelet Aggregation ◽  
Dense Body ◽  
Platelet Rich Plasma ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Creatine Phosphate ◽  
Calcium Flux ◽  
Fibrinogen Receptor ◽  
Induced Aggregation

Abstract We demonstrate that zinc (0.1 to 0.3 mmol/L) induces aggregation of washed platelet suspensions. Higher concentrations (1 to 3 mmol/L) of zinc were needed to aggregate platelets in platelet-rich plasma obtained from blood anticoagulated with low-molecular-weight heparin, probably due to the binding of zinc to the plasma proteins. Zinc- induced aggregation of normal washed platelets required added fibrinogen and no aggregation occurred with thrombasthenic platelets or with normal platelets pretreated with a monoclonal antibody (10E5) that blocks the platelet fibrinogen receptor. These data indicate that the platelet membrane fibrinogen receptor-glycoproteins IIb and IIIa mediate the effect of zinc. Zinc-induced aggregation was blocked by the agent TMB-8, which interferes with the internal calcium flux, and by prostacyclin, which elevates platelet cyclic adenosine monophosphate levels. Zinc-induced aggregation was not accompanied by thromboxane synthesis or by the secretion of dense-body serotonin and was not affected by preexposure of platelets to acetylsalicylic acid. Experiments with creatine phosphate/creatine phosphokinase showed that the zinc effect on platelets was independent of extracellular adenosine diphosphate (ADP). Zinc had an additive effect when platelet aggregation was stimulated with subthreshhold concentrations of collagen or ADP. Together with the known effects of nutritional zinc on in vivo bleeding, on platelet aggregation, and on lipid metabolism, the results suggest that zinc may have an important bearing on normal hemostasis, thrombosis, and atherosclerosis.

scholarly journals Determination of loratadine in pharmaceuticals by a spectrophotometric method

2015 ◽  
Vol 26 (1) ◽  
pp. 27-31
Author(s):  
Georgeta Pavalache ◽  
Nicoleta Matei ◽  
Antoanela Popescu
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Reading Time ◽  
Pharmaceutical Formulations ◽  
Mixed Composition ◽  
Oral Formulations ◽  
Short Time

Abstract The spectrophotometric method for determination of loratadine using tetraiodomercurate has been applied in various pharmaceutical formulations. The results confirmed that recovery value is optimum and the method is valid, thus it can be used in quality control and evaluation of loratadine tablets, oral formulations of mixed composition, oral solutions, etc. The method is easy and simple to apply, does not require complicated equipment and spectrophotometric reading time is reduced, which allows a large number of analyzes in a relatively short time.

scholarly journals DETERMINATION OF SIMULTANEOUS IRBESARTAN AND HYDROCHLOROTHIAZIDE BY ULTRAVIOLET SPECTROPHOTOMETRY WITH DUAL WAVELENGTH METHOD

1970 ◽  
Vol 7 (3) ◽  
pp. 1-4 ◽  
Author(s):  
Hafid Syahputra ◽  
M. Si. Apt Muchlisyam ◽  
M.S. Apt Masfria
Keyword(s):  
Blood Pressure ◽  
Quality Control ◽  
Spectrophotometric Method ◽  
Reduce Blood Pressure ◽  
Dual Wavelength ◽  
Good Precision ◽  
Ultraviolet Spectrophotometry ◽  
Validation Parameters ◽  
Precision And Accuracy

Objective: The present study was aimed to develop a spectrophotometric method by dual wavelength method in simultaneous analysis of irbesartan and hydrochlorothiazide on tablet preparations without separation. Irbesartan and hydrochlorothiazide are a group of anti-hypertensive drugs that are very effective and safe to use to reduce blood pressure and edema. These drugs often given in combination with these active ingredients can cause problems in quantitative analysis for the quality control of preparations. Methods: The study was carried out experimentally with a spectrophotometric method, one of which was dual wavelength method and then tested its validity based on validation parameters, namely linearity, accuracy, precision, LOD and LOQ and intraday and interday. Then, this method of irbesartan and hydrochlorothiazide in tablet preparations. Results: The results of the study were showed that the application of dual wavelength method on the concentration was carried out at λ 263.4 nm and 281 nm for irbesartan and at λ 243.4 nm and 247.6 nm for hydrochlorothiazide. The results obtained by irbesartan and hydrochlorothiazide on tablets were (108.04 ± 2.696) and (94.28 ± 4.48)% respectively, and with good precision and accuracy. Conclusions: The ultraviolet spectrophotometry method is dual wavelength method successfully applied for the determination of the concentration of irbesartan and hydrochlorothiazide in tablets.

scholarly journals The Use of 7,7′,8,8′-Tetracyanoquinodimethane for the Spectrophotometric Determination of Some Primary Amines Application to Real Water Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Theia'a N. Al-Sabha ◽  
Najwa M. Al-Karemy
Keyword(s):  
Charge Transfer ◽  
Quantitative Determination ◽  
Spectrophotometric Method ◽  
Aromatic Amines ◽  
Molar Absorptivity ◽  
Primary Amines ◽  
Charge Transfer Complexes ◽  
Buffer Solution ◽  
Real Water Samples

A sensitive, simple, and accurate spectrophotometric method was developed for the quantitative determination of some primary aliphatic and aromatic amines, that is, ethylamine, 1,2-diaminopropane, aniline, p-aminophenol, and benzidine. The method is based on the interaction of these amines in aqueous medium with 7,7′,8,8′-tetracyanoquinodimethane (TCNQ) reagent in the presence of a buffer solution and surfactant (in the case of aromatic amines) to form charge-transfer complexes measurable at maximum wavelengths ranging between 323 and 511 nm. Beer’s law is obeyed over the concentration ranges of 0.025 and 3.0 μg/mL and the molar absorptivity is ranged between 8.977 × 103and 5.8034 × 104 L·mol−1·cm−1for these amines. The method was applied for the determination of benzidine in the river, sea, and tap waters. The TCNQ complexes with the previously mentioned amines were formed in the ratio of 1 : 1 amine : TCNQ, and their stability constants ranged between 8.78 × 104and 1.844 × 105 L·mol−1.

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