Least-Squares Regression and Spectral Residual Augmented Classical Least-Squares Chemometric Models for Stability-Indicating Analysis of Agomelatine and Its Degradation Products: A Comparative Study

2016 ◽  
Vol 99 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Ibrahim A Naguib ◽  
Maha M Abdelrahman ◽  
Mohamed R El Ghobashy ◽  
Nesma A Ali
Keyword(s):  
Comparative Study ◽  
Least Squares ◽  
Multivariate Calibration ◽  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Forced Degradation ◽  
Least Squares Regression ◽  
Prediction Ability ◽  
Stability Indicating ◽  
Spectral Residual

Abstract Two accurate, sensitive, and selective stability-indicating methods are developed and validated for simultaneous quantitative determination of agomelatine (AGM) and its forced degradation products (Deg I and Deg II), whether in pure forms or in pharmaceutical formulations. Partial least-squares regression (PLSR) and spectral residual augmented classical least-squares (SRACLS) are two chemometric models that are being subjected to a comparative study through handling UV spectral data in range (215–350 nm). For proper analysis, a three-factor, four-level experimental design was established, resulting in a training set consisting of 16 mixtures containing different ratios of interfering species. An independent test set consisting of eight mixtures was used to validate the prediction ability of the suggested models. The results presented indicate the ability of mentioned multivariate calibration models to analyze AGM, Deg I, and Deg II with high selectivity and accuracy. The analysis results of the pharmaceutical formulations were statistically compared to the reference HPLC method, with no significant differences observed regarding accuracy and precision. The SRACLS model gives comparable results to the PLSR model; however, it keeps the qualitative spectral information of the classical least-squares algorithm for analyzed components.

scholarly journals Stability Indicating HPTLC Method for Analysis of Rifaximin in Pharmaceutical Formulations and an Application to Acidic Degradation Kinetic Study

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kalpana G. Patel ◽  
Nitesh R. Jain ◽  
Purvi A. Shah
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Degradation Process ◽  
Order Rate Constant ◽  
Forced Degradation ◽  
Phase System ◽  
Degradation Kinetic ◽  
Stability Indicating ◽  
Acidic Degradation

A specific stability indicating high-performance thin-layer chromatographic method for analysis of rifaximin both as a bulk drug and in formulations was developed and validated. The method employed HPTLC aluminium plates precoated with silica gel 60 F254 as the stationary phase. The optimized mobile phase system consisted of n-hexane : 2-propanol : acetone : ammonia (5 : 4.1 : 1, v/v/v/v), which gave compact spots for rifaximin at of 0.59 ± 0.03. Rifaximin was subjected to forced degradation studies in order to check the specificity of the method. Densitometric analysis of rifaximin was carried out in the absorbance reflectance mode at 443 nm. The calibration plots showed linear relationship in the concentration range of 400–3200 ng per band. Moreover, linearity was also confirmed by verification of homoscedasticity of variance. According to validation studies, the developed method was repeatable and specific as revealed by % RSD less than 2 and hence can be used for routine analysis of pharmaceutical formulation. Moreover, the method could effectively separate the drug from its degradation products; hence it can be employed as a stability indicating one. The kinetics of acid degradation process at various temperatures was also investigated and first-order rate constant, half-life, shelf life, and activation energy were computed.

A New Validated Stability Indicating RP-HPLC Method for the Quantification of Allopurinol and Lesinurad in Bulk and Pharmaceutical Formulations

2020 ◽  
Vol 5 (1) ◽  
pp. 51-55
Author(s):  
K.V. Ramanjaneyulu ◽  
K. Venkata Ramana ◽  
M. Prasada Rao
Keyword(s):  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Forced Degradation ◽  
Analysis Method ◽  
Degradation Study ◽  
Stability Indicating ◽  
Stress Study ◽  
Isocratic Hplc ◽  
Bulk Drug

The objective of this study was to develop and validate a method for simultaneous quantitative analysis of allopurinol and lesinurad in bulk drug and pharmaceutical formulations. An isocratic HPLC analysis method using a reverse phase Waters spherisorb ODS1 C18 column (250 mm × 4.6 mm, 5 μ) and a simple mobile phase without buffer was developed, optimized and fully validated. Analyses were carried out at a flow rate of 0.9 mL/min at 50 °C and monitored at 246 nm. This HPLC method exhibited good linearity, accuracy and selectivity. The recovery (accuracy) of both allopurinol and lesinurad from all matrices was greater than 98 %. The allopurinol and lesinurad peak detected in the samples of a forced degradation study and no interference of excepients or the degradation products formed during stress study. The method was rugged with good intra- and inter-day precision and sensitive. This stability indicating HPLC method was selective, accurate and precise for the simultaneous analysis of allopurinol and lesinurad in pharmaceutical formulations.

scholarly journals Development and Validation of Three Stability-Indicating Methods for Determination of Bisacodyl in Pure Form and Pharmaceutical Preparations

2007 ◽  
Vol 90 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Fadia H Metwally ◽  
Mohammed Abdelkawy ◽  
Ibrahim A Naguib
Keyword(s):  
Least Squares ◽  
Degradation Products ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Principal Component ◽  
Standard Addition ◽  
Raw Material ◽  
Prediction Ability ◽  
Stability Indicating

Abstract Three new, simple, sensitive, and accurate stability-indicating methods were developed for quantitative determination of bisacodyl in the presence of its degradation products, monoacetyl bisacodyl (I) and desacetyl bisacodyl (II), in enteric coated tablets, suppositories, and raw material. The first is a spectrodensitometric method in which the drug is separated from I and II on silica gel plates using chloroformacetone (9 + 1, v/v) as the mobile phase with ultraviolet detection of the separated bands at 223 nm over a concentration range of 0.2-1.4 g/band for bisacodyl with mean recovery 100.35 ± 1.923%. The second method is fourth derivative D4 spectrophotometry, which allows determination of bisacodyl in the presence of its degradation products in raw material at 223 nm using acetonitrile as the solvent with adherence to Beer's law over the concentration range 2-18 μg/mL with mean recovery 99.77 ± 1.056%. In the third method, the spectrophotometric data of bisacodyl, I, and II using absolute ethanol as solvent were processed by 3 chemometric techniques: classical least-squares, principal component regression, and partial least-squares. A training set consisting of 15 mixtures containing different ratios of bisacodyl, I, and II was used for construction of the 3 models. A validation set consisting of 6 mixtures was used to validate the prediction ability of the suggested models. The 3 chemometric methods were applicable over a concentration range between 2-14 μg/mL for bisacodyl with mean recovery of 99.97 ± 0.865, 100.01 ± 0.749, and 99.97 ± 0.616% for the 3 models, respectively. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied to the analysis of raw material and pharmaceutical formulations containing bisacodyl, except for the second method that applies only for raw material. The validity of the suggested procedures was further assessed by applying the standard addition technique; the recoveries obtained were in accordance with those given by the reference method.

Stability Indicating Liquid Chromatographic Method for the Determination of Fenofibrate and its Application to Kinetic Studies

2013 ◽  
Vol 5 (4) ◽  
pp. 1866-1874
Author(s):  
K. Srinivasa Rao ◽  
Keshar N K ◽  
N Jena ◽  
M.E.B Rao ◽  
A K Patnaik
Keyword(s):  
Degradation Products ◽  
Kinetic Studies ◽  
Pharmaceutical Formulations ◽  
Assay Method ◽  
Pharmaceutical Dosage Form ◽  
Stability Indicating ◽  
Zero Order Kinetics ◽  
Relative Standard ◽  
Liquid Chromatographic

A stability-indicating LC assay method was developed for the quantitative determination of fenofibrate (FFB) in pharmaceutical dosage form in the presence of its degradation products and kinetic determinations were evaluated in acidic, alkaline and peroxide degradation conditions. Chromatographic separation was achieved by use of Zorbax C18 column (250 × 4.0 mm, 5 μm). The mobile phase was established by mixing phosphate buffer (pH adjusted 3 with phosphoric acid) and acetonitrile (30:70 v/v). FFB degraded in acidic, alkaline and hydrogen peroxide conditions, while it was more stable in thermal and photolytic conditions. The described method was linear over a range of 1.0-500 μg/ml for determination of FFB (r= 0.9999). The precision was demonstrated by relative standard deviation (RSD) of intra-day (RSD= 0.56– 0.91) and inter-day studies (RSD= 1.47). The mean recovery was found to be 100.01%. The acid and alkaline degradations of FFB in 1M HCl and 1M NaOH solutions showed an apparent zero-order kinetics with rate constants 0.0736 and 0.0698  min−1 respectively and the peroxide degradation with 5% H2O2 demonstrated an apparent first-order kinetics with rate constant k = 0.0202 per min. The t1/2, t90   values are also determined for all the kinetic studies. The developed method was found to be simple, specific, robust, linear, precise, and accurate for the determination of FFB in pharmaceutical formulations.  

Determination of Pyridostigmine Bromide in Presence of its Related Impurities by Four Modified Classical Least Square Based Models: A Comparative Study

2020 ◽  
Vol 17 (1) ◽  
pp. 87-94
Author(s):  
Ibrahim A. Naguib ◽  
Fatma F. Abdallah ◽  
Aml A. Emam ◽  
Eglal A. Abdelaleem
Keyword(s):  
Comparative Study ◽  
Least Squares ◽  
Orthogonal Projection ◽  
Predictive Ability ◽  
Least Square ◽  
Projection To Latent Structures ◽  
Preprocessing Method ◽  
Spectral Residual ◽  
Latent Structures

: Quantitative determination of pyridostigmine bromide in the presence of its two related substances; impurity A and impurity B was considered as a case study to construct the comparison. Introduction: Novel manipulations of the well-known classical least squares multivariate calibration model were explained in detail as a comparative analytical study in this research work. In addition to the application of plain classical least squares model, two preprocessing steps were tried, where prior to modeling with classical least squares, first derivatization and orthogonal projection to latent structures were applied to produce two novel manipulations of the classical least square-based model. Moreover, spectral residual augmented classical least squares model is included in the present comparative study. Methods: 3 factor 4 level design was implemented constructing a training set of 16 mixtures with different concentrations of the studied components. To investigate the predictive ability of the studied models; a test set consisting of 9 mixtures was constructed. Results: The key performance indicator of this comparative study was the root mean square error of prediction for the independent test set mixtures, where it was found 1.367 when classical least squares applied with no preprocessing method, 1.352 when first derivative data was implemented, 0.2100 when orthogonal projection to latent structures preprocessing method was applied and 0.2747 when spectral residual augmented classical least squares was performed. Conclusion: Coupling of classical least squares model with orthogonal projection to latent structures preprocessing method produced significant improvement of the predictive ability of it.

scholarly journals Rapid tannin profiling of tree fodders using untargeted mid-infrared spectroscopy and partial least squares regression

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Jordi Ortuño ◽  
Sokratis Stergiadis ◽  
Anastasios Koidis ◽  
Jo Smith ◽  
Chris Humphrey ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Least Squares ◽  
Partial Least Squares ◽  
Partial Least Squares Regression ◽  
Multivariate Calibration ◽  
Plant Ecology ◽  
Coefficient Of Determination ◽  
Least Squares Regression ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy

Abstract Background The presence of condensed tannins (CT) in tree fodders entails a series of productive, health and ecological benefits for ruminant nutrition. Current wet analytical methods employed for full CT characterisation are time and resource-consuming, thus limiting its applicability for silvopastoral systems. The development of quick, safe and robust analytical techniques to monitor CT’s full profile is crucial to suitably understand CT variability and biological activity, which would help to develop efficient evidence-based decision-making to maximise CT-derived benefits. The present study investigates the suitability of Fourier-transformed mid-infrared spectroscopy (MIR: 4000–550 cm−1) combined with multivariate analysis to determine CT concentration and structure (mean degree of polymerization—mDP, procyanidins:prodelphidins ratio—PC:PD and cis:trans ratio) in oak, field maple and goat willow foliage, using HCl:Butanol:Acetone:Iron (HBAI) and thiolysis-HPLC as reference methods. Results The MIR spectra obtained were explored firstly using Principal Component Analysis, whereas multivariate calibration models were developed based on partial least-squares regression. MIR showed an excellent prediction capacity for the determination of PC:PD [coefficient of determination for prediction (R2P) = 0.96; ratio of prediction to deviation (RPD) = 5.26, range error ratio (RER) = 14.1] and cis:trans ratio (R2P = 0.95; RPD = 4.24; RER = 13.3); modest for CT quantification (HBAI: R2P = 0.92; RPD = 3.71; RER = 13.1; Thiolysis: R2P = 0.88; RPD = 2.80; RER = 11.5); and weak for mDP (R2P = 0.66; RPD = 1.86; RER = 7.16). Conclusions MIR combined with chemometrics allowed to characterize the full CT profile of tree foliage rapidly, which would help to assess better plant ecology variability and to improve the nutritional management of ruminant livestock.

scholarly journals Validated Stability Indicating RP-HPLC Method for Simultaneous Estimation of Codeine Phosphate and Chlorpheniramine Maleate from Their Combined Liquid Dosage Form

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ramakrishna Kommana ◽  
Praveen Basappa
Keyword(s):  
Limit Of Detection ◽  
Degradation Products ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Forced Degradation ◽  
Codeine Phosphate ◽  
Chlorpheniramine Maleate ◽  
Combination Drug ◽  
Stability Indicating ◽  
Rp Hplc

The present paper describes the development of quick stability indicating RP-HPLC method for the simultaneous estimation of codeine phosphate and chlorpheniramine maleate in the presence of its degradation products, generated from forced degradation studies. The developed method separates codeine phosphate and chlorpheniramine maleate in impurities/degradation products. Codeine phosphate and chlorpheniramine maleate and their combination drug product were exposed to acid, base, oxidation, dry heat, and photolytic stress conditions, and the stressed samples were analysed by proposed method. The proposed HPLC method utilizes the Shimadzu HPLC system on a Phenomenex C18 column (, 5 μ) using a mixture of 1% o-phosphoric acid in water : acetonitrile : methanol (78 : 10 : 12) mobile phase with pH adjusted to 3.0 in an isocratic elution mode at a flow rate of 1 mL/min, at 23°C with a load of 20 μL. The detection was carried out at 254 nm. The retention time of codeine phosphate and chlorpheniramine maleate was found to be around 3.47 min and 9.45 min, respectively. The method has been validated with respect to linearity, robustness, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ). The developed validated stability indicating HPLC method was found to be simple, accurate, and reproducible for the determination of instability of these drugs in bulk and commercial products.

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