Improved Method for Determination of Triglycerides in Serum

1973 ◽  
Vol 19 (10) ◽  
pp. 1201-1202 ◽  
Author(s):  
Bruce P Neri ◽  
Christopher S Frings
Keyword(s):  
Confidence Level ◽  
Coefficient Of Variation ◽  
Room Temperature ◽  
Original Method ◽  
New Method ◽  
Improved Method ◽  
Serum Triglycerides ◽  
Accuracy And Precision ◽  
Significant Difference

Abstract We describe a new method for determination of serum triglycerides that is based on the original method of Fletcher [Clin. Chim. Acta22, 393 (1968)]. We have modified Fletcher’s reagents so that it is possible to saponify serum triglycerides in 5 min at room temperature (about 24 °C) instead of 60-70 °C for 15 min and to produce the final color in 15 min at 60-70 °C instead of 30 min at 50 ° C. The new reagents are stable for at least two months. The correlation coefficient obtained for the two methods (n = 107 sera) was 0.98. When the t test and F test were applied to these data, no significant difference in accuracy and precision was found at the 95% confidence level. The coefficient of variation (day-to-day) for the new method is 7.0%.

Simple Manual Procedure for Determination of Serum Triglycerides

1975 ◽  
Vol 21 (6) ◽  
pp. 768-770 ◽  
Author(s):  
Jose Mendez ◽  
Barry Franklin ◽  
Harry Gahagan
Keyword(s):  
Quality Control ◽  
Calibration Curve ◽  
Room Temperature ◽  
Extraction Procedure ◽  
Serum Triglycerides ◽  
Modified Method ◽  
Color Development ◽  
Significant Difference ◽  
Control Samples

Abstract We describe a modified method for determining serum triglycerides (triacylglycerols), which is based on the heptane extraction procedure of Gottfried and Rosenberg [Clin. Chem. 19, 1077 (1973)] with the stable saponification, oxidation, and color development reagents of Neri and Frings [Clin. Chem. 19, 1201 (1973)]. This modified method eliminates one heating step, reduces saponification time to 5 min, absorbances are read at room temperature, and the calibration curve is linear to 3.0 g/liter. A sample comparison between the proposed method and the automated Block and Jarrett [Am. J. Med. Technol. 35, 1 (1969)] procedure showed no significant difference (r = 0.98). The coefficient of variation (47 duplicate samples) for the modified method was 6.3%. Further validation was obtained from analysis of quality-control samples; the proposed method gave equivalent values.

scholarly journals A kinetic spectrophotometric method for the determination of lansoprazole in pharmaceutical formulations

2006 ◽  
Vol 71 (10) ◽  
pp. 1107-1120 ◽  
Author(s):  
Nafisur Rahman ◽  
Zehra Bano ◽  
Hejaz Azmi ◽  
Mohammad Kashif
Keyword(s):  
Spectrophotometric Method ◽  
Room Temperature ◽  
Pharmaceutical Formulations ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results ◽  
Calibration Equations ◽  
Method Show

Asimple kinetic spectrophotometric method has been developed for the determination of lansoprazole in pharmaceutical formulations. The method is based on the oxidation of the drug with alkaline potassium permanganate at room temperature. The reaction was followed spectrophotometrically by measuring the increase in the absorbance owing to the formation of MnO 42? at 610 nm (Method A) and the decrease in the absorbance at 530 nm due to the disapperance of MnO4? (Method B). Calibration procedures were adopted for the assay of the drug. The calibration curves were linear over the concentration ranges of 5-150 and 5-70?g ml-1, with the corresponding calibration Equations: rate = -3.915x10-6 + 5.271x10-5 c and ?A = 1.04x 10-3 + 1.78x10-3 c for methods A, and B, respectively. A statistical comparison of the results of the proposed procedures with those of the reference spectrophotometric method show excellent agreement and indicated no significant difference between the compared methods in terms of accuracy and precision. Interval hypothesis tests were also performed, which indicated that the true bias of all samples was less than ? 2 %. .

Simplified, totally enzymatic method for determination of serum triglycerides with a centrifugal analyzer.

1976 ◽  
Vol 22 (8) ◽  
pp. 1310-1313 ◽  
Author(s):  
S H Grossman ◽  
E Mollo ◽  
G Ertingshausen
Keyword(s):  
Present Method ◽  
Room Temperature ◽  
Fixed Time ◽  
Glycerol Dehydrogenase ◽  
Enzymatic Method ◽  
Serum Triglycerides ◽  
Acceptable Accuracy ◽  
Accuracy And Precision ◽  
Enzymatic Procedure

Abstract We describe a totally enzymatic method for determination of serum triglycerides (triacylglycerols) specifically adaptable to the CentrifiChem system. The method involves lipolysis with lipase from Rhizopus arrhizus alone and quantitation of the resulting glycerol with glycerol dehydrogenase in a kinetic, fixed-time mode. Hydrolysis by the lipase is complete, for concentrations up to at least 5.0 g/liter, in 10 min at room temperature. The unfavorable equilibrium for the oxidation of glycerol is overcome by increasing the pH and adding excess NAD+. Under these conditions the glycerol determination is linear to at least 4.0 g of glycerol per liter, as triglyceride. The test exhibits acceptable accuracy and precision, and results correlate well with those by an alternative totally enzymatic procedure. The present method is unaffected by phosphatase and a considerably simplified reagent is used.

Comparative Study for the Assay of Plant Derived Chemicals in Pharmaceutical Formulation Using Methods Dependent on Factorized Spectra

2021 ◽  
Author(s):  
Nesma M Fahmy ◽  
Adel M Michael
Keyword(s):  
Pharmaceutical Formulations ◽  
Pharmaceutical Formulation ◽  
Ternary Mixtures ◽  
Ratio Method ◽  
The Novel ◽  
Naturally Occurring ◽  
Accuracy And Precision ◽  
Validation Parameters ◽  
Significant Difference

Abstract Background Modern built-in spectrophotometer software supporting mathematical processes provided a solution for increasing selectivity for multicomponent mixtures. Objective Simultaneous spectrophotometric determination of the three naturally occurring antioxidants—rutin(RUT), hesperidin(HES), and ascorbic acid(ASC)—in bulk forms and combined pharmaceutical formulation. Method This was achieved by factorized zero order method (FZM), factorized derivative method (FD1M), and factorized derivative ratio method (FDRM), coupled with spectrum subtraction(SS). Results Mathematical filtration techniques allowed each component to be obtained separately in either its zero, first, or derivative ratio form, allowing the resolution of spectra typical to the pure components present in Vitamin C Forte® tablets. The proposed methods were applied over a concentration range of 2–50, 2–30, and 10–100 µg/mL for RUT, HES, and ASC, respectively. Conclusions Recent methods for the analysis of binary mixtures, FZM and FD1M, were successfully applied for the analysis of ternary mixtures and compared to the novel FDRM. All were revealed to be specific and sensitive with successful application on pharmaceutical formulations. Validation parameters were evaluated in accordance with the International Conference on Harmonization guidelines. Statistical results were satisfactory, revealing no significant difference regarding accuracy and precision. Highlights Factorized methods enabled the resolution of spectra identical to those of pure drugs present in mixtures. Overlapped spectra of ternary mixtures could be resolved by spectrum subtraction coupled FDRM (SS-FDRM) or by successive application of FZM and FD1M.

scholarly journals Spectrophotometric determination of dothiepin hydrochloride in pharmaceuticals through ion-pair complexation reaction

2012 ◽  
Vol 18 (2) ◽  
pp. 339-347 ◽  
Author(s):  
Sameer Abdulrahman ◽  
Kanakapura Basavaiah
Keyword(s):  
Ion Pair ◽  
Pure Form ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Complexation Reaction ◽  
Conditional Stability ◽  
Conditional Stability Constant ◽  
Accuracy And Precision ◽  
Significant Difference

Two simple, sensitive and extraction-free spectrophotometric methods are described for the determination of dothiepin hydrochloride (DOTH) both in pure form and in pharmaceutical tablets. The methods are based on ion-pair complex formation between dothiepin base (DOT) and two acidic dyes, namely, bromophenol blue (BPB) or bromocresol green (BCG) with absorption maximum at 425 nm for BPB method or 430 nm for BCG method. Beer?s law is obeyed over the concentration ranges of 1.0-15.0 and 1.0-17.5 ?g mL-1 DOT for BPB and BCG methods, respectively. The molar absorptivity values and Sandell?s sensitivity values are reported for both methods. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.18 and 0.53 ?g mL-1 for BPB method, and 0.17 and 0.50 ?g mL-1 for BCG method, respectively. The stoichiometry of the complex in either case was found to be 1: 1 and the conditional stability constant (KF) of the complexes has also been calculated. The proposed methods were applied successfully to the determination of DOTH in pure form and in its tablet form with good accuracy and precision. Statistical comparison of the results was performed using Student's t-test and variance ratio F-test at 95% confidence level and there was no significant difference between the official and proposed methods with regard to accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique.

VALIDATED RP-HPLC AND UV-SPECTROSCOPY METHODS FOR THE ESTIMATION OF DAPAGLIFLOZIN IN BULK AND IN TABLETS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (03) ◽  
pp. 44-51
Author(s):  
B. Sabbagh ◽  
B. V. S. Lokesh ◽  
G. A. Akouwah ◽  
Keyword(s):  
Good Accuracy ◽  
Uv Spectroscopy ◽  
Linear Regression Analysis ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Uv Visible

Two methods were developed for the determination of dapagliflozin (DAPA) in pure form and in tablets. The procedure utilized was UV-Visible Spectroscopy and RP-HPLC with PDA detector to quantify DAPA in bulk and tablets. The sensitive linear range was identified for both methods within 0.5-5.0μg/mL. The linear regression analysis was identified for both methods with correlation coefficient(r)>0.99. The LOD and LOQ values were found to be 0.05 μg/mL and 0.5 μg/mL for the method by UV-Spectroscopy. The molar absorptivity (ε) was calculated as 1.27 X 105 L.mol-1cm-1. The RP-HPLC method produced LOD and LOQ values of 1.0 ng/mL and 0.5 μg/mL. Both methods were simple, precise, reproducible to quantify the amount of unknown in bulk as well as in tablets and estimated accurately within the range of 100.0±0.5%. Statistical analysis was performed on the data obtained. There was no significant difference between the developed and reported methods with p>0.05. Both methods can be applied for routine analysis of DAPA in bulk and tablets with good accuracy and precision.

scholarly journals Stability indicating HPLC-Fluorescence detection method for the simultaneous determination of linagliptin and empagliflozin in their combined pharmaceutical preparation

2021 ◽  
Vol 12 (2) ◽  
pp. 168-178
Author(s):  
Mohamed Rizk ◽  
Ali Kamal Attia ◽  
Heba Yosry Mohamed ◽  
Mona Elshahed
Keyword(s):  
Fluorescence Detection ◽  
Mobile Phase ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Forced Degradation ◽  
Stability Indicating ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Significant Difference

A sensitive, accurate, and precise liquid chromatographic method has been developed and validated for the determination of Linagliptin (LNG) and Empagliflozin (EMP) in their combined tablets. Chromatographic separation was carried out on ODS-3 Inertsil® C18 column (150×4.6 mm, 5 µm). The mobile phase A (consisting of 0.30% Triethyl amine buffer (TEA) at pH = 4.5, adjusted using ortho-phosphoric acid); the mobile phase B (consisting of acetonitrile) was pumped through the column whose temperature was maintained at 40 °C, with a flow rate 1.7 mL/min, using gradient elution from 0-3 min A:B (75:25, v:v), then from 3-6 min the ratio changed to be A:B (60:40, v:v). Fluorescence detection (FLD) was performed at 410 nm after excitation at 239 nm. Acceptable linearity, accuracy and precision values of the proposed method were found over the concentration ranges of 0.5-15 µg/mL for LNG and 1.0-30 µg/mL for EMP with correlation coefficients of 0.9997 and 0.9998 in the case of LNG and EMP, respectively. The recoveries and relative standard deviations percentages were found in the following ranges: 98.56-101.85 and 0.53-1.52% for LNG and 98.00-101.95 and 0.31-1.05% for EMP. The detection and quantification limits were 0.15 and 0.45 µg/mL for LNG and 0.22 and 0.67 µg/mL for EMP. The optimized method was validated and proved to be specific, robust, accurate and reliable for the determination of the drugs in pure form or in their combined pharmaceutical preparations. No significant difference was found regarding accuracy and precision upon statistical comparison between the obtained results of the proposed method and those of the reported method. Furthermore, the proposed method is proved to be a stability-indicating assay after exposure of the studied drugs to variable forced degradation parameters, such as acidic, alkaline and oxidative conditions, according to the recommendations of the International Conference on Harmonization guidelines. The simplicity and selectivity of the proposed method allows its use in quality control laboratories.

scholarly journals Spectrophotometric Determination of Doxazosin Mesylate in Tablets by Ion-Pair and Charge-Transfer Complexation Reactions

2009 ◽  
Vol 92 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Zeynep Aydomu ◽  
Asli Barla
Keyword(s):  
Charge Transfer ◽  
Ion Pair ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Charge Transfer Reaction ◽  
Accuracy And Precision ◽  
Doxazosin Mesylate ◽  
Significant Difference ◽  
Complexation Reactions

Abstract Two accurate, easy spectrophotometric methods for the determination of doxazosin mesylate were described. The first method was based on the formation of ion-pair complexes with the acidic sulfophthalein dyes bromocresol purple (BCP) and bromophenol blue (BPB) in pH 3.3 and 4.5 citratephosphate buffer, respectively. The formed complexes were extracted into dichloromethane, and their absorbance was measured at 403 and 410 nm for BCP and BPB, respectively. The second method was based on the charge transfer reaction of the drug as an n-electron donor with either 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or 7,7,8,8-tetracyanoquinodimethane (TCNQ) as -acceptors, to give colored radical anions. The absorbances of products were measured at 457 nm in acetonitrile and 838 nm in methanol for DDQ and TCNQ, respectively. Under the optimum reaction conditions, Beer's law was obeyed with a good correlation coefficient (r = 0.99970.9999) in the concentration ranges 3.018.0, 3.020.0, 15.095.0, and 10.0100.0 g/mL for the BCP, BPB, DDQ, and TCNQ methods, respectively. Limits of detection of the BCP, BPB, DDQ, and TCNQ methods were 0.314, 0.408, 1.935, and 1.610 g/mL, respectively. The limits of quantification were 1.045, 1.360, 6.449, and 5.367 g/mL, respectively. The parameters molar absorptivity, precision, accuracy, recovery, robustness, and stability constant were studied. The proposed methods were successfully applied for determination of the drug in tablets with good accuracy and precision. Statistical comparison of the results with those obtained by a reported method showed good agreement and indicated no significant difference in accuracy and precision.

Spectrophotometric Methods for Simultaneous Determination of Sofosbuvir and Ledipasvir (HARVONI Tablet): Comparative Study with Two Generic Products

2017 ◽  
Vol 100 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Nisreen F Abo-Talib ◽  
Mohamed R El-Ghobashy ◽  
Marwa H Tammam
Keyword(s):  
Dosage Form ◽  
Drug Dosage ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Drug Dosage Form ◽  
Generic Products ◽  
Third Derivative ◽  
Combination Pill

Abstract Sofosbuvir and ledipasvir are the first drugs in a combination pill to treat chronic hepatitis C virus. Simple, sensitive, and rapid spectrophotometric methods are presented for the determination of sofosbuvir and ledipasvir in their combined dosage form. These methods were based on direct measurement of ledipasvir at 333 nm (due to the lack of interference of sofosbuvir) over a concentration range of 4.0–14.0 µg/mL, with a mean recovery of 100.78 ± 0.64%. Sofosbuvir was determined, without prior separation, by third-derivative values at 281 nm; derivative ratio values at 265.8 nm utilizing 5.0 µg/mL ledipasvir as a divisor; the ratio difference method using values at 270 and 250 nm using 5.0 µg/mL ledipasvir as a divisor; and the ratio subtraction method using values at 261 nm. These methods were found to be linear for sofosbuvir over a concentration range of 5.0–35.0 µg/mL. The suggested methods were validated according to International Conference on Harmonization guidelines. Statistical analysis of the results showed no significant difference between the proposed methods and the manufacturer's LC method of determination with respect to accuracy and precision. These methods were used to compare the equivalence of an innovator drug dosage form and two generic drug dosage forms of the same strength.

scholarly journals Effect of Various Diluents on the Activity of Several Enzymes Present in Serum

1973 ◽  
Vol 19 (9) ◽  
pp. 1079-1080
Author(s):  
Ted W Fendley ◽  
Jane M Hochholzer ◽  
Christopher S Frings
Keyword(s):  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Confidence Level ◽  
Aspartate Aminotransferase ◽  
Nacl Solution ◽  
Manual Method ◽  
Accuracy And Precision ◽  
Significant Difference

Abstract We have evaluated the effect of diluting serum with water or NaCl solution (8.5 or 9.0 g/liter) before assaying by a manual method for creatine kinase (EC 2.7.3.2), alkaline phosphatase (EC 3.1.3.1), lactate dehydrogenase (EC 1.1.1.27), and aspartate aminotransferase (EC 2.6.1.1) activity. The t test and the F test show no significant difference in the accuracy and precision of the assays at the 95% confidence level when 100 different samples were compared for each enzyme activity after use of the three diluents.

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