Standardization of Glycohemoglobin Determinations in the Clinical Laboratory: Three Years of Experience

1992 ◽  
Vol 38 (12) ◽  
pp. 2414-2418 ◽  
Author(s):  
G S Bodor ◽  
R R Little ◽  
N Garrett ◽  
W Brown ◽  
D E Goldstein ◽  
...  

Abstract Measurement of glycohemoglobin has been recommended for the long-term assessment of glycemic control in diabetic patients. Because different analytical methods measure different glycohemoglobin species, it has been difficult to compare results between laboratories. Here we report 3 years of experience with calibration of an affinity chromatography method for measuring total glycohemoglobin (GHb). Calibration was achieved by including in each assay three hemolysate calibrators for which values for HbA1c and GHb had been determined by repeated analyses by high-performance liquid chromatography (HPLC) and affinity chromatography, respectively. Calibration improved interassay precision (CV = 3.20-7.90% and < 5.0% before and after the introduction of calibration, respectively) and eliminated lot-to-lot variability. In 91 samples, HbA1c was estimated by the calibrated affinity chromatography assay and measured by an ion-exchange HPLC method. Estimated and HPLC-measured HbA1c showed no clinically significant differences during 36 months. The high degree of long-term precision, the disappearance of lot-to-lot variability, and the excellent comparability between analytical methods measuring different species of glycated hemoglobins demonstrate the advantages of calibration.

Author(s):  
N. S. Shulyak ◽  
A. D. Abbeyquaye ◽  
D. B. Koval

Introduction. Innovative pharmaceutical development of various antihypertensive drugs with statins and the creation of domestic fixed-dose combinations of drugs with different effects is an urgent task of modern pharmacy, which will help attract more patients to the treatment and prevention of cardiovascular disease. Pharmaceutical development of atorvastatin and lisinopril by our scientific group proposes for using the ratio of (1/1) for lisinopril (10 mg) and atorvastatin (10 mg). HPLC (High-Performance Liquid Chromatography) technique is adopted as it is considered as the most common technique in realm of quality control analysis. The aim of the study – to evaluate the robustness of HPLC (High-Performance Liquid Chromatography) method for the quantitation of lisinopril and atorvastatin and determine the analytical parameters that present greater influence in the final results of the analysis. Research Methods. An efficient method to assess the robustness of analytical methods is by Youden’s test, by means of an experiment design which involves seven analytical parameters combined in eight tests. In the recent studies, we assessed the robustness of a chromatographic method to quantify lisinopril and atorvastatin in tablets using Youden’s test. Results and Discussion. By using the criteria of Youden’s test, HPLC method proved to be greatly robust regarding content of lisinopril and atorvastatin, when variations in seven analytical parameters were introduced. The most variation in effects of the analytical parameters in retention time (Rt) for lisinopril and atorvastatin HPLC quantitation was when used column supplier. Purospher C8 STAR (55 mm x 4mm, 5 μm) is based on high purity silica and an almost complete surface coverage. Purospher C8 STAR provides excellent peak symmetry for acidic, basic and even chelating compounds, highest column efficiency in terms of the number of theoretical plates, and exceptional stability from pH 1.5 to 10.5. Conclusion. Youden’s test can be applied successfully for the ro­bustness evaluation in validation process of analytical methods and results ontained in our work should be interest to the scientific population dealing with pharmaceutical analytical chemistry.


2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.


2006 ◽  
Vol 89 (6) ◽  
pp. 1552-1556
Author(s):  
ArmaĞan Önal ◽  
Olcay SaĞiri ◽  
S Müge Çetin ◽  
Sidika Toker

Abstract Reboxetine is used as a selective noradrenaline reuptake inhibitor for the treatment of major depressive disorders. It is effective in the treatment of severe depression and safer to use than traditional tricyclic antidepressants. In this study, a novel, simple, and rapid stability-indicating high-performance liquid chromatography (HPLC) method for reboxetine methansulfonate was successfully developed and validated for the assay of tablets. The method was used to quantify reboxetine in tablets; it employed a C18 column (150 4.6 mm id) with an isocratic mobile phase consisting of methanolphosphate buffer (pH 7, 0.02 M; 55 + 45, v/v) at a flow rate of 1.0 μmL/min. Reboxetine was detected by an ultraviolet detector at 277 nm. The retention time of reboxetine was about 4.5 min. The developed HPLC method was validated with respect to linearity, precision, sensitivity, accuracy, and selectivity. The method was linear over the concentration range 150 g/mL (r 0.9999). The limits of detection and the quantitation of reboxetine were 0.1 and 0.3 μg/mL, respectively. The relative standard deviation values for intraday and interday precision were 0.781.01 and 1.081.37%, respectively. Selectivity was validated by subjecting a stock solution of reboxetine to neutral, acid, and alkali hydrolysis, as well as oxidation, dry heat treatment, and photodegradation. The peaks of the degradation products did not interfere with the peak of reboxetine. The results indicated that the proposed method could be used in a stability assay. The proposed method was successfully applied to the determination of reboxetine in tablets. Excipients present in the tablets did not interfere with the analysis.


INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (11) ◽  
pp. 46-50
Author(s):  
Z. G Khan ◽  
◽  
S. S. Patil ◽  
P. K. Deshmukh ◽  
P. O. Patil

Novel, isocratic reversed phase high performance liquid chromatography method was developed and validated for the determination of enzalutamide (EZA) in bulk drug and pharmaceutical formulation. Efficient separation was achieved on PrincetonSPHER C18 100A, 5μ (250×4.6 mm) under the isocratic mode of elution using acetonitrile: water (80:20) % V/V as a mobile phase pumped in to the column at flow rate 1.0 mL/min. The effluent was monitored at 237.0 nm using UV detector. EZA was eluted in the given mobile phase at retention time (tR) of 3.2 minutes. The standard calibration curve was linear over the concentration range 10 - 60 μg/mL with correlation coefficient 0.997. The method was validated for accuracy, precision, sensitivity, robustness, ruggedness and all the resulting data treated statistically. The system suitability parameters like retention time, theoretical plates, tailing factor, capacity factor were found within the limit.


INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (01) ◽  
pp. 35-40
Author(s):  
A. S. Bagde ◽  
V. V. Khanvilkar ◽  

The present work describes a validated reverse phase high performance liquid chromatography (RPHPLC) method for simultaneous estimation of dextromethorphan hydrobromide and quinidine sulphate in pharmaceutical dosage from. The drugs were resolved using Hemochrom Intsil C18-5U column (250×4.6) mm in isocratic mode with mobile phase methanol: water (0.08% diethylamine, 0.02% of glacial acetic acid and pH 4.4 adjusted with orthophosphoric acid) in the ratio of 70:30 V/V at a flow rate of 1.0 mL/min. Retention time of dextromethorphan hydrobromide and quinidine sulphate were 4.9±0.2 and 3.6±0.2, respectively, at 292nm. The above mentioned method was validated as per International Conference on Harmonization (ICH) guidelines. Linear responses were obtained in concentration ranges of 5-35 μg/mL for dextromethorphan hydrobromide and 4-16 μg/mL for quinidine sulphate, with correlation coefficient (r2) of 0.999 for both the drugs. A simple, selective, accurate, precise, robust and reliable RP-HPLC method thus developed and validated for simultaneous estimation of dextromethorphan hydrobromide and quinidine sulphate.


2007 ◽  
Vol 26 (6) ◽  
pp. 535-544 ◽  
Author(s):  
E. Köhler ◽  
S. Avenarius ◽  
A. Rabsilber ◽  
C. Gerloff ◽  
G. Jorch

Meconium samples collected from 115 neonates were analysed for nicotine, cotinine and trans -3-hydroxycotinine (OH-cotinine) by means of high-performance liquid chromatography (HPLC) to identify prenatal smoke exposure. The self-reported maternal smoking status during pregnancy was determined by means of a questionnaire and verified by measurements in urine prior to childbirth. The total sum of nicotine and its metabolites (Sumtot) of the first passed meconium samples was 1560 ± 1024 pmol/g in newborns of smoking mothers. Smoking of less than five cigarettes was clearly detected. Sumtot remained constant in all meconium samples passed by a neonate in succession. However, the proportion of nicotine decreased with the time of passage after birth and the OH-cotinine proportion increased, whereas cotinine hardly changed. Nicotine or its metabolites were not detectable in meconium (detection limit < 20 pmol/g), when the mothers were only exposed to environmental tobacco smoke (ETS) using the HPLC method. The hypothesis that the content of nicotine metabolites in meconium reflects long-term smoke exposure could not be confirmed in newborns whose mothers had quit smoking during the latter half of pregnancy. Determining Sumtot enables the intensity of continuous smoking during pregnancy to be estimated in all meconium samples passed by a newborn. Human & Experimental Toxicology (2007) 26: 535—544


2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S213-S216 ◽  
Author(s):  
D. Komes ◽  
D. Horžić ◽  
A. Belščak ◽  
K. Kovačević Ganič ◽  
A. Baljak

Caffeine-containing products have been consumed for hundreds of years for their pleasant flavor and stimulating effects. In recent years, caffeine received increasing attention in food and pharmaceutical industries, due to its pharmacological properties which comprise stimulation of the central nervous system, peripheral vasoconstriction, relaxation of the smooth muscle and myocardial stimulation. The aim of this study was to determine the content of caffeine in five types of tea (white, yellow, green, oolong, black) and two types of maté tea (green maté and roasted maté tea). The content of caffeine was determined by using four different methods: extraction with chloroform, micromethod, method with lead-acetate and high performance liquid chromatography method (HPLC-PDA). The antioxidant capacity of teas as well as of the extracted (“raw”) caffeine was determined by using two methods: reactions with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical (ABTS assay) and Ferric reducing antioxidant power (FRAP assay). The content of caffeine has been associated with plant origin and growth conditions, as well as processing conditions. By applying all four methods, the highest content of caffeine was determined in white tea, whereas maté and roasted maté tea were characterised with the lowest content of caffeine. Spectrophotometric micro-method has proven to be the best alternative to the HPLC method. The highest antioxidant capacity was determined in yellow tea, while the lowest was determined in roasted maté tea. In comparison to the antioxidant capacity of teas, the antioxidant capacity of extracted (“raw”) caffeine is almost negligible, and does not contribute to the overall antioxidant properties of tea.


INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (11) ◽  
pp. 42-49
Author(s):  
C Dhal ◽  
◽  
F. J. Ahmad ◽  
M. Singhal ◽  
A. Kukrety ◽  
...  

An accurate, sensitive, precise, economic and rapid isocratic Reverse Phase High Performance Liquid Chromatography method was developed complying Quality by Design (QbD) trends and validated for determining doxycycline hyclate in bulk drug, tablet and capsule dosage form. The method was optimized using Minitab software with 3 factors (pH of the buffer, flow rate and percentage of buffer in the mobile phase), 2 level (higher limit and lower limit) Central Composite Design (CCD). The results of randomized 20 runs were analyzed for optimum composite desirability to give optimum conditions such as, pH 6.5, flow rate 0.9 mLmin-1 and 30:70 V/V 0.05M potassium dihydrogen orthophosphate buffer adjusted to pH 6.5 using orthophosphoric acid and methanol using C8 column 250 X 4.6 mm X 5.0 μm, injection volume of 10uL, ambient column temperature and ultraviolet detection using photo diode array detector at 360nm as constants. The method was validated as per ICH guidelines and was found linear over a concentration range of 10-100 μg/mL (r2 = 0.999) with the limits of detection and quantification being 2.45 μg/mL and 7.55 μg/mL respectively.


2021 ◽  
Vol 09 ◽  
Author(s):  
Priyanka Narula ◽  
Komal Saini ◽  
Megha Saini ◽  
Dinesh Singla ◽  
Anurag Singh Chauhan ◽  
...  

Background: Envisaging the poor solubility (56ng/ml) and permeability of tetrahydrocurcumin (THCC), it was formulated into lipidic nanostructures to enhance its bioavailability upon topical application to promote the healing process for skin inflammatory disorders. Lack of literature on suitable method for determining THCC per se and nanoformulations prompted us to develop a RP-HPLC method to detect the drug in its nanostructures and in pig ear skin post dermatokinetics. Objective: The present investigation aimed to develop a simple, precise and RP-HPLC method for the quantitative estimation of THCC in prepared lipidic nanostructures, its ointment and in skin homogenate obtained post dermatokinetic study. Method: THCC encapsulated nanostructures and ointment were formulated using modified emulsification method and embedded into an ointment base to enhance its spreadability and improve patient compliance. A fast and sensitive reverse phase high performance liquid chromatography method was developed using a Hypersil BDS reverse phase C18 column (4.6 mm × 250 mm, 5 μm) with mobile phase comprising tetrahydrofuran (THF) and 1 mgmL-1 citric acid (4:6), at a flow rate of 1.0 mLmin−1 with a run time of 20 min. Result: THCC nanostructures were successfully prepared using spontaneous microemulsification method. THCC was detected at 282 nm and revealed two peaks which were attributed to the keto-enol tautomerism in the molecule with retention times of 6.23 min and 11.06 min respectively. The assay of THCC in nanostructures and ointment was found to be 98.30% and 99.98% with entrapment efficiency 77.00±2.74 %. The dermatokinetic studies revealed sufficient release of THCC from its ointment up till 24 hr with a concentration of 1382 μgcm-2, for causing a therapeutic effect. Conclusion: The method was found to be reproducible and robust as shown by low coefficient of variation and a constant analyte/IS ratio. It was successfully employed for the estimation of THCC assay in nanostructures and it’s ointment and dermatokinetic analysis in skin.


Author(s):  
Anuja Kolsure ◽  
Kratika Daniel ◽  
Mahesh Bhat

Budesonide is a potent glucocorticoid with a high local anti-inflammatory effect and low systemic bioavailability. The inhaled form is used in the long-term management of asthma and chronic obstructive pulmonary disease. Several analytical methods including UV, HPLC, LC-MS techniques has been developed for Budesonide alone and in combination with others. Methods indicating HPLC bioanalytical method, stability indicating HPLC method, ion pairing chromatographic method and chemometrics assisted HPLC methods are also described for Budesonide. For qualitative and quantitative estimation of Budesonide these analytical methods can be used. The following study describes reported analytical methods of Budesonide.


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