scholarly journals Quantitative Determination of Vitamins A and E in Ointments Using Raman Spectroscopy

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Sylwester Mazurek ◽  
Kamil Pichlak ◽  
Roman Szostak

A quantitative analysis of vitamins A and E in commercial ointments containing 0.044% and 0.8% (w/w) of active pharmaceutical ingredients, respectively, was performed using partial least squares models based on FT Raman spectra. Separate calibration systems were prepared to determine the amount of vitamin A in a petrolatum base ointment and to quantify vitamins A and E in a eucerin base one. Compositions of the laboratory-prepared and commercial samples were controlled through a principal component analysis. Relative standard errors of prediction were calculated to compare the predictive ability of the obtained regression models. For vitamin A determination, these errors were found to be in the 3.8–5.0% and 5.7–5.9% ranges for the calibration and validation data sets, respectively. In the case of vitamin E modeling, these errors amounted to 3.7% and 4.4%. On the basis of elaborated models, vitamins A and E were successfully quantified in two commercial products with recoveries in the 99–104% range. The obtained data indicate that the Raman technique allows for accurate analysis of the composition of semisolid formulations in their native state, including low dose preparations.

2012 ◽  
Vol 95 (3) ◽  
pp. 744-750 ◽  
Author(s):  
Sylwester Mazurek ◽  
Roman Szostak

Abstract The quantification of prednisone in tablets was performed using partial least squares (PLS) models based on FTIR-attenuated total reflection (ATR) and FT-Raman spectra. To compare the predictive ability of these models, the relative standard error of prediction (RSEP) values were calculated. In the case of prednisone determination from the FT-Raman data, RSEP values of 3.1 and 3.2% for the calibration and validation data sets were obtained. For FTIR-ATR models, which were constructed using five spectra for each sample, these errors amounted to 2.6 and 2.9%, respectively. Four commercial products containing 1, 5, 10, and 20 mg prednisone/tablet were quantified. Concentrations derived from the elaborated models correlated strongly with the results of reference analyses and with the declared values (in parentheses). The analyses gave recoveries of 100.0–101.6% (100.1–103.0%) and 98.1–103.2% (100.4–102.9%) for FTIR-ATR and FT-Raman data, respectively. A successful quantification of prednisolone in tablets containing 5 mg active ingredient/tablet was also performed using the PLS model, which was based on FTIR-ATR spectra, with a recovery of 99.8 (98.8%). Both reported spectroscopic techniques can be used as fast and convenient alternatives to the standard pharmacopeial methods of prednisone and prednisolone quantification in solid dosage forms. However, in the case of FTIR-ATR spectroscopy, it is necessary to repeat measurements several times to obtain sufficiently low quantification errors.


2013 ◽  
Vol 96 (5) ◽  
pp. 1073-1081 ◽  
Author(s):  
Adrienne McMahon ◽  
Scott Christiansen ◽  
Lynsey Shine ◽  
Calvin Loi ◽  
Dawn Dowell

Abstract This HPLC method, with both variable UV and fluorescence detection, allows for the simultaneous determination of vitamin A palmitate, vitamin A acetate, and total vitamin E in infant, pediatric, and adult nutritional formulas. The concentration of each vitamin form is calculated by comparison with standards of known concentration. Following hydrolysis, the vitamins are extracted into iso-octane and analyzed by normal phase (NP) HPLC. The method was evaluated for linearity, precision, and accuracy using a selection of the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) matrixes, including milk-based, soy-based, and hydrolyzed protein, as well as high- and low-fat products. A single-laboratory validation has been completed for all analytes using a selection of SPIFAN matrixes. Performance parameters included a working range of 2–450 μg/100 g ready-to-feed for vitamin A and 0.03–8.0 mg/100 g reconstituted final product for vitamin E. LOD was <1.0 μg and <0.1 mg/100 g reconstituted final product for vitamins A and E, respectively; RSD was 1.08–8.70% over a range of concentration; and average recoveries of 97.4–101.3%. Repeatability of <4% for vitamin A and <8% for vitamin E was calculated from five laboratories using this method. Results indicate that this method is suitable for the analysis of vitamins A and E in all forms of infant, adult, and pediatric formulas (powders, ready-to-feed liquids, and liquid concentrates). The Expert Review Panel (ERP) of Infant Formula reviewed this method separately for vitamins A and E, including all available method validation data at the AOAC INTERNATIONAL Annual Meeting on September 29, 2012. Following evaluation of the data for both methods, the ERP agreed that both methods met the standard method performance requirements articulated by SPIFAN. The ERP granted First Action status to both methods, and recommended that a single method be published for the simultaneous determination of vitamin A palmitate, vitamin A acetate, and total vitamin E (DL-α-tocopherol and DL-α-tocopherol acetate) in infant formula and adult nutritionals by NP HPLC.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Roghaieh Khoshkam ◽  
Minoo Afshar

A rapid and stability-indicating RP-HPLC method was developed for determination of l-carnitine in tablets. The separation was based on a C18 analytical column using a mobile phase which consisted of 0.05 M phosphate buffer (pH = 3): ethanol (99 : 1), including 0.56 mg/mL of sodium 1-heptanesulfonate. Column temperature was set at 50°C and quantitation was achieved by UV detection at 225 nm. In forced degradation studies, the drug was subjected to oxidation, hydrolysis, photolysis, and heat. Among the different stress conditions, the exposure to acidic and basic conditions was found to be an important adverse stability factor. The method was validated for specificity, selectivity, linearity, precision, accuracy, and robustness. The applied procedure was found to be linear in l-carnitine concentration range of 84.74–3389.50 µg/mL (r2=0.9997). Precision was evaluated by replicate analysis in which relative standard deviation (RSD) values for areas were found below 2.0%. The recoveries obtained (100.83%–101.54%) ensured the accuracy of the developed method. The expanded uncertainty (3.14%) of the method was also estimated from method validation data. Accordingly, the proposed validated and rapid procedure was proved to be suitable for routine analyzing and stability studies of l-carnitine in tablets.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Fahimeh Sadeghi ◽  
Latifeh Navidpour ◽  
Sima Bayat ◽  
Minoo Afshar

A green, simple, and stability-indicating RP-HPLC method was developed for the determination of diltiazem in topical preparations. The separation was based on a C18analytical column using a mobile phase consisted of ethanol: phosphoric acid solution (pH = 2.5) (35 : 65, v/v). Column temperature was set at 50°C and quantitation was achieved with UV detection at 240 nm. In forced degradation studies, the drug was subjected to oxidation, hydrolysis, photolysis, and heat. The method was validated for specificity, selectivity, linearity, precision, accuracy, and robustness. The applied procedure was found to be linear in diltiazem concentration range of 0.5–50 μg/mL (r2=0.9996). Precision was evaluated by replicate analysis in which % relative standard deviation (RSD) values for areas were found below 2.0. The recoveries obtained (99.25%–101.66%) ensured the accuracy of the developed method. The degradation products as well as the pharmaceutical excipients were well resolved from the pure drug. The expanded uncertainty (5.63%) of the method was also estimated from method validation data. Accordingly, the proposed validated and sustainable procedure was proved to be suitable for routine analyzing and stability studies of diltiazem in pharmaceutical preparations.


2012 ◽  
Vol 95 (2) ◽  
pp. 322-328
Author(s):  
Jonathan W DeVries ◽  
Karlene R Silvera ◽  
Elliot McSherry ◽  
Dawn Dowell

Abstract During the “Standards Development and International Harmonization: AOAC INTERNATIONAL Mid- Year Meeting,” held on June 29, 2011, an Expert Review Panel (ERP) reviewed the method for the “Determination of Vitamins A (Retinol) and E (alpha-Tocopherol) in Foods by Liquid Chromatography: Collaborative Study,” published by Jonathan W. DeVries and Karlene R. Silvera in J. AOAC Int. in 2002. After evaluation of the original validation data, an ERP agreed in June 2011 that the method meets standard method performance requirements (SMPRs) for vitamin A, as articulated by the Stakeholder Panel on Infant Formula and Adult Nutritionals. The ERP granted the method First Action status, applicable to determining vitamin A in ready-to-eat infant and adult nutritional formula. In an effort to achieve Final Action status, it was recommended that additional information be generated for different types of infant and adult nutritional formula matrixes at varied concentration levels as indicated in the vitamin A (retinol) SMPR. Existing AOAC LC methods are suited for specific vitamin A analytical applications. The original method differs from existing methods in that it can be used to assay samples in all nine sectors of the food matrix. One sector of the food matrix was powdered infant formula and gave support for the First Action approval for vitamin A in infant and adult nutritional formula. In this method, standards and test samples are saponified in basic ethanol–water solution, neutralized, and diluted, converting fats to fatty acids and retinol esters to retinol. Retinol is quantitated by an LC method, using UV detection at 313 or 328 nm for retinol. Vitamin concentration is calculated by comparison of the peak heights or peak areas of retinol in test samples with those of standards.


2005 ◽  
Vol 88 (3) ◽  
pp. 761-772 ◽  
Author(s):  
Paul McNabb ◽  
Andrew I Selwood ◽  
Patrick T Holland ◽  
J Aasen ◽  
T Aune ◽  
...  

Abstract A method that uses liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been developed for the highly sensitive and specific determination of amnesic shellfish poisoning toxins, diarrhetic shellfish poisoning toxins, and other lipophilic algal toxins and metabolites in shellfish. The method was subjected to a full single-laboratory validation and a limited interlaboratory study. Tissue homogenates are blended with methanol-water (9 + 1), and the centrifuged extract is cleaned up with a hexane wash. LC/MS/MS (triple quadrupole) is used for quantitative analysis with reversed-phase gradient elution (acidic buffer), electrospray ionization (positive and negative ion switching), and multiple-reaction monitoring. Ester forms of dinophysis toxins are detected as the parent toxins after hydrolysis of the methanolic extract. The method is quantitative for 6 key toxins when reference standards are available: azaspiracid-1 (AZA1), domoic acid (DA), gymnodimine (GYM), okadaic acid (OA), pectenotoxin-2 (PTX2), and yessotoxin (YTX). Relative response factors are used to estimate the concentrations of other toxins: azaspiracid-2 and -3 (AZA2 and AZA3), dinophysis toxin-1 and -2 (DTX1 and DTX2), other pectenotoxins (PTX1, PTX6, and PTX11), pectenotoxin secoacid metabolites (PTX2-SA and PTX11-SA) and their 7-epimers, spirolides, and homoYTX and YTX metabolites (45-OHYTX and carboxyYTX). Validation data have been gathered for Greenshell mussel, Pacific oyster, cockle, and scallop roe via fortification and natural contamination. For the 6 key toxins at fortification levels of 0.05–0.20 mg/kg, recoveries were 71–99% and single laboratory reproducibilities, relative standard deviations (RSDs), were 10–24%. Limits of detection were <0.02 mg/kg. Extractability data were also obtained for several toxins by using successive extractions of naturally contaminated mussel samples. A preliminary interlaboratory study was conducted with a set of toxin standards and 4 mussel extracts. The data sets from 8 laboratories for the 6 key toxins plus DTX1 and DTX2 gave within-laboratories repeatability (RSDr) of 8–12%, except for PTX-2. Between-laboratories reproducibility (RSDR) values were compared with the Horwitz criterion and ranged from good to adequate for 7 key toxins (HorRat values of 0.8–2.0).


1995 ◽  
Vol 78 (3) ◽  
pp. 659-662 ◽  
Author(s):  
Mark R Coleman ◽  
James S Peloso ◽  
John W Moran

Abstract A microbiological agar plate assay is described for determination of tilmicosin in bovine blood serum. The serum or serum dilution is added directly to wells cut in the agar plates. Tilmicosin activity is determined by measuring the zone of bacterial growth inhibition in agar medium inoculated with Micrococcus luteus, ATCC 9341. The assay was validated by evaluating the following parameters: accuracy, precision, linearity, parallelism, ruggedness, storage stability, and relative activity of isomers. Accuracy was evaluated with freshly collected bovine serum and with commercially available sera. Recoveries ranged from 93.4 to 97.5% across a fortification range of 0.08 to 1.28 μg/mL. Precision was estimated over a 6-day period with serum obtained from a tilmicosin-treated animal. Relative standard deviations were 0.63 to 3.13% within day and 5.23% across 6 days. Standard curves were linear with little variation in slope. No parallelism was observed between tilmicosin in serum and tilmicosin in buffered saline. The limit of detection was estimated to be 0.05 μg/mL, and the validated limit of quantitation was 0.08 μg/mL. Ruggedness was evaluated with different lots of antibiotic medium, different lots of sera, and different analysts. These variables did not affect method performance. Analyses of tilmicosin in frozen sera demonstrated that tilmicosin is stable for up to 16 days when stored at −20°C. A comparison of the relative microbiological activities of the purified cis and trans isomers of tilmicosin to that of the reference standard indicated no differences in microbiological activities, and showed a parallel response among the 3. The validation data demonstrate that this method is a rugged, reliable, and simple assay for tilmicosin in serum.


2019 ◽  
Vol 15 (5) ◽  
pp. 542-553
Author(s):  
Hui Zhao ◽  
Hao Cai ◽  
Juan-Xiu Liu ◽  
Sheng-Nan Wang ◽  
Xun-Hong Liu ◽  
...  

Background: Xanthium sibiricum is a well-known traditional Chinese medicine (TCM) that has been commonly used to treat rhinitis and related nasal diseases. The aim of this study was to develop a comprehensive analytical method based on high-performance liquid chromatographyelectrospray ionization coupled with triple quadrupole-linear ion trap mass spectrometry (LC-ESIQTRAP- MS/MS) for the simultaneous determination of phenolic acids, anthraquinones, and flavonoids in the aerial part and fruit of Xanthium sibiricum. Methods: The separation was completed on Agilent ZORBAX SB-C18 column (250 × 4.6 mm, 5μm) using methanol and 0.2% (v/v) aqueous formic acid as the mobile phase. The target components were analyzed in negative ion mode with accurate and sensitive multiple reaction monitoring (MRM) mode. Results: The correlation coefficients of all the calibration curves were higher than 0.9994. Relative standard deviations of intra- and inter-day precisions of the eighteen components were all lower than 2.87% and the recoveries were in the range from 97.73% to 101.82%. The validated method was successfully applied to possess forty Xanthium sibiricum samples (Xanthii Herba, Xanthii Fructus, and processed Xanthii Fructus) collected from different places in P. R. China. Furthermore, principal component analysis (PCA) was performed to evaluate and classify the samples according to the contents of the eighteen bioactive components. Conclusion: All the results demonstrated that the developed method was useful and could be applied for the overall assessment of the quality of Xanthii Herba and Xanthii Fructus.


2014 ◽  
Vol 13 (2) ◽  
pp. 182-196
Author(s):  
Adriána Bednárová ◽  
Roman Kranvogl ◽  
Darinka Brodnjak-Vončina ◽  
Tjaša Jug

Abstract The determination of the sensorial quality of wines is of great interest for wine consumers and producers since it declares the quality in most of the cases. The sensorial assays carried out by a group of experts are time-consuming and expensive especially when dealing with large batches of wines. Therefore, an attempt was made to assess the possibility of estimating the wine sensorial quality with using routinely measured chemical descriptors as predictors. For this purpose, 131 Slovenian red wine samples of different varieties and years of production were analysed and correlation and principal component analysis were applied to find inter-relations between the studied oenological descriptors. The method of artificial neural networks (ANNs) was utilised as the prediction tool for estimating overall sensorial quality of red wines. Each model was rigorously validated and sensitivity analysis was applied as a method for selecting the most important predictors. Consequently, acceptable results were obtained, when data representing only one year of production were included in the analysis. In this case, the coefficient of determination (R2) associated with training data was 0.95 and that for validation data was 0.90. When estimating sensorial quality in categorical form, 94 % and 85 % of correctly classified samples were achieved for training and validation subset, respectively.


2007 ◽  
Vol 90 (3) ◽  
pp. 686-692 ◽  
Author(s):  
Ragaa El-Shiekh ◽  
Alaa S Amin ◽  
Faten Zahran ◽  
Ayman A Gouda

Abstract Three simple, sensitive, and reproducible spectrophotometric methods (AC) for the determination of pipazethate hydrochloride (PiCl) in pure form and in pharmaceutical formulations are described. The first and second methods, A and B, are based on the oxidation of the drug by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH values was demonstrated at 510 and 522 nm, respectively, with o-phen and bipy. The third method, C, is based on the reduction of Fe(III) by PiCl in acid medium and subsequent interaction of Fe(II) with ferricyanide to form Prussian blue, which exhibits an absorption maximum at 750 nm. The concentration ranges are from 0.5 to 8, 2 to 16, and 3 to 15 g/mL for Methods AC, respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, and detection and quantitation limits were calculated. The developed methods were successfully applied to the determination of PiCl in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were 0.83% with recoveries of 98.9101.15%.


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