Advanced chemometric methods for simultaneous quantitation of caffeine, codeine, paracetamol, and p-aminophenol in their quaternary mixture.

Two different multivariate techniques have been applied for the quantitative analysis of caffeine, codeine, paracetamol and p-aminophenol (PAP) in quaternary mixture, namely, Partial Least Squares (PLS-1) and Artificial Neural Networks (ANN). For suitable analysis, a calibration set of 25 mixtures with various ratios of the drugs and PAP impurity were established using a 4-factor 5-level experimental design. The most meaningful wavelengths for the chemometric models were chosen using Genetic Algorithm (GA) as a variable selection technique. By using an independent validation set, the validity of the proposed methods was evaluated. A comparative study was established between the three multivariate models (PLS-1, GA-PLS and GA-ANN). The comparison between the various models revealed that the GA-ANN model was superior at resolving the highly overlapped spectra of this quaternary combination. The drugs were successfully quantified in their pharmaceutical dosage form utilizing the GA-ANN models.

Continuous wavelet transform for solving the problem of minor components in quantitation of pharmaceuticals: a case study on the mixture of ibuprofen and phenylephrine with its degradation products.

The presence of minor components represents a challenging problem in spectrophotometric analysis of pharmaceuticals. If one component has a low absorptivity or present in a low concentration compared to the other components, this will hinder its quantitation by spectrophotometric methods. Continuous Wavelet Transform (CWT) as a signal processing technique was utilized to figure out a solution to such a problem. A comparative study was established between traditional derivative spectrophotometry (Numerical Differentiation, ND) and CWT to indicate the advantages and limitations of each technique and possibility of solving the problem of minor components. A mixture of ibuprofen (IBU) and phenylephrine (PHE) with its degradation products forming a ternary mixture was used for comparing the two techniques. The two techniques were applied on raw spectral data and on ratio spectra data resulting in four methods, namely ND, CWT, Derivative Ratio-Zero Crossing (DRZC) and Continuous Wavelet Transform Ratio-Zero Crossing (CWTR-ZC) methods. By comparing the results in laboratory prepared mixtures, CWT technique showed advantages in analysis of mixtures with minor components than ND. The proposed methods were validated according to the ICH guideline Q2(R1), where their linearity was established with correlation coefficient ranging from 0.9995 to 0.9999. The linearity was in the range 3-40 µg/mL for PHE in all methods, while for IBU it was 20-180 and 30-180 µg/mL in CWT and ND methods, respectively. The CWT methods were applied for quantitative determination of the drugs in their dosage form showing the ability of the methods to quantitate minor components in pharmaceutical formulations.

Development of an eco-friendly HPLC method for the stability indicating assay of binary mixture of ibuprofen and phenylephrine.

The development and validation of the stability indicating HPLC technique has contributed to the understanding of the stability profile of ibuprofen (IBU) and phenylephrine (PHE). Stability profile was achieved for PHE; the drug was found to be liable to be influenced by stress oxidative conditions; two oxidative degradants (Deg1 & Deg2) were formed and their structures were confirmed using IR and mass spectrometry. The drugs and degradation products were successfully separated using a gradient elution method on YMC-C8 column with 0.1% hexanesulfonic acid and acetonitrile as a mobile phase at pH 6.6. The flow rate was 1.0 mL/min, and a diode array detector operating at 220 nm was used for UV detection. The retention times of degradants Deg1, Deg2, ibuprofen (IBU), and phenylephrine hydrochloride (PHE) were 2.0, 2.2, 3.2 and 7.0 min, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness using ICH guidelines. The linearities of ibuprofen and phenylephrine hydrochloride were in the range of 10-100 µg/mL and 0.3-10 µg/mL, respectively. The % recoveries of the two drugs were found to be 100.75 ± 1.44%, 99.67% ± 1.67, and the LOD was found to be 2.75/mL and 0.09/mL for IBU, and PHE, respectively. The method was successfully applied to the estimation of ibuprofen and phenylephrine hydrochloride combination in pharmaceutical dosage form. The proposed technique was validated using ICH guidelines and its greenness was assessed according to Analytical Eco Scale metric (AES). Molecular docking was used to assess the two drugs and PHE oxidative degradants interaction with the stationary phase and to confirm the outcomes of the proposed method with regard to the order of elution of the two drugs and PHE degradation products. Eco-friendly and environmental safety were assessed through the application of one of the most applicable greenness assessment tool; Analytical Eco Scale metric (AES).

Sustainable chromatographic quantitation of multi-antihypertensive medications: application on diverse combinations containing hydrochlorothiazide along with LC-MS/MS profiling of potential impurities: greenness and whiteness evaluation.

Cardiovascular disorders are among the leading causes of death worldwide, especially hypertension, a silent killer syndrome requiring multiple drug therapy for appropriate management. Hydrochlorothiazide is an extensively utilized thiazide diuretic that combines with several antihypertensive drugs for effective treatment of hypertension. In this study, sustainable, innovative and accurate high performance liquid chromatographic methods with diode array and tandem mass detectors (HPLC-DAD and LC-MS/MS) were developed, optimized and validated for the concurrent determination of Hydrochlorothiazide (HCT) along with five antihypertensive drugs, namely; Valsartan (VAL), Amlodipine besylate (AML), Atenolol (ATN), Amiloride hydrochloride (AMI), and Candesartan cilextil (CAN) in their diverse pharmaceutical dosage forms and in the presence of Chlorothiazide (CT) and Salamide (DSA) as HCT officially identified impurities. The HPLC-DAD separation was achieved utilizing Inertsil ODS-3 C18 column (250 × 4.6 mm, 5 µm) attached with photodiode array detection at 225.0 nm. Gradient elution was performed utilizing a mixture of solvent A (20.0 mM potassium dihydrogen phosphate, pH 3.0 ± 0.2, adjusted with phosphoric acid) and solvent B (acetonitrile) at ambient temperature. Linearity ranges were 0.1-100.0 µg/mL for HCT, VAL, AML and CAN, 0.05 -100.0 µg/mL for both ATN and AMI and 0.05-8.0 µg/mL for both CT and DSA. Additionally, this work describes the use of liquid chromatography-electrospray-tandem mass spectrometry for the accurate detection and quantification of the impurities; CT and DSA in the negative mode utilizing triple quadrupole mass spectrometry. The linearity ranges for those impurities were 1.0-200.0 ng/mL and 5.0-200.0 ng/mL for CT and DSA, respectively. Developed methods' validation was achieved in accordance with International Conference on Harmonization (ICH) guidelines. Upon applying liquid chromatographic techniques for the drug analysis, a green and sustainable assessment have to be handled due to the consumption of energy and many solvents. Through the use of the HEXAGON, Analytical Greenness (AGREE) and White Analytical Chemistry (WAC) tools, greenness and sustainability have been statistically assessed. The optimized HPLC-DAD and LC-MS/MS methods were fast, accurate, precise, and sensitive, and consequently could be applied for conventional analysis and quality control of the proposed drugs in their miscellaneous dosage forms for the purpose of reducing laboratory wastes, time of the analysis time, effort, and cost.

Coupling of physical extraction and mathematical filtration in spectrophotometric analysis of natural therapy essential for prophylaxis and treatment of COVID-19 infection - Comparative study along with greenness evaluation.

Diosmin (DIO) and hesperidin (HSP) are important classes of flavonoid glycoside effectively used to prevent comorbid diseases that are commonly associated with COVID-19. An innovative, green, ccurate, effective, cost, and timeless spectrophotometric strategy was established to analyze such challengeable mixture in a co-formulated tablet namely Diosed C® tablets that comprises DIO, HSP and vitamin C (VIT. C) in the ratio of (450 mg: 50 mg: 100 mg) necessary for prevention and treatment of COVID-19. Vitamin C was resolved through physical extraction using de-ionized water while DIO and HSP were extracted via spectrophotometric methods using two different solvents [0.1 M NaOH or solvent blend consisting of DMSO and methanol (1:1)]. Mathematical filtration technique is successfully applied to recover the parent spectra of both DIO and HSP via three methods which are absorbance resolution (AR), Induced absorbance resolution (IAR) and ratio extraction (RE). VIT. C was successfully analyzed in de-ionized water using its maxima at 266.0 nm in a linearity range 2.0-20.0 µg/mL, DIO was effectively determined in 0.1 M NaOH at 372.0 nm in a linearity range of 7.0-70.0 µg/mL as well as in solvent blend at 344.0 nm in linearity range of 5.0-55.0 µg/mL while HSP was accurately analyzed in 0.1 M NaOH at 240.0 nm in linearity range of 3.5-50.0 µg/mL as well as in solvent blend at 285.0 nm in linearity range of 4.0-50.0 µg/mL. Satisfactory results were accomplished when conducting ICH guidelines for assuring the methods validation. Comparative study was introduced in the analysis of such critical combination and was prosperously devoted for the effective analysis of pharmaceutical dosage form. The proposed extraction pathways undergo the guidelines of green analytical chemistry using Analytical Eco-Scale (AES), AGREE and GAPI greenness assessment tools which confirmed their eco-friendly nature with priority to 0.1 M NaOH. The obtained results of the suggested methods were set side by side with those of official/reported methods statistically and show satisfactory implications. The presented methods were simple, affordable, smoothly applicable and their results were acceptable that enhances their usage and application in the quality control laboratories.

Green analytical chemistry and experimental design: a combined approach for the analysis of zonisamide.

Green analytical chemistry principles, as well as experimental design, are a combined approach adopted to develop sensitive reproducible stability indicating HPLC method for Zonisamide (ZNS) determination. The optimal conditions for three chromatographic parameters were determined using a central composite design of the response surface. Kromasil C18 column (150 mm × 4.6 mm, 5 µm) was utilized with ethanol, H2O (30:70 v/v) as a mobile phase at a flow rate of 1 mL/min at 35 °C. Good reproducibility and high sensitivity were achieved along (0.5-10 µg/mL) concentration range. In contrast, the TLC-densitometric method was performed on aluminum plates precoated with silica gel 60F254 as a stationary phase and chloroform: methanol: acetic acid (8:1.5:0.5 by volume) as a developing system. Reproducible results were obtained in the range of (2-10 µg/band). The chromatograms of HPLC and TLC were scanned at 280 nm and 240 nm, respectively. The suggested methods have been validated following ICH guidelines, and no statistically significant differences were detected between the results of the current study and the official USP method. It was also found that using experimental design implements the green concept by reducing the environmental impact. Finally, Eco-Scale, GAPI and AGREE were used to assess the environmental impacts of the suggested methods.

Three developed spectrophotometric methods for determination of a mixture of ofloxacin and ornidazole; application of greenness assessment tools.

This work is dedicated to the greenness estimation of three proposed spectrophotometric techniques [e.g., ratio difference (RD), mean centering of ratio spectra (MCR) and continuous wavelet transform of ratio spectra (CWT)] for the determination of a binary combination named Ofloxacin (OFL) and Ornidazole (ORN). Applying the green analytical chemistry methods to assess the proposed methods has widely attained the analytical community care. The greenness assessment was performed via three evaluation approaches; the "Analytical Eco-Scale", the "National Environmental Method Index" (NEMI) and "Green Analytical Procedure Index" (GAPI). Following the examination of the zero spectrum of OFL and ORN, it is observed that OFL and ORN spectra are overlapped, so they can be detected by the methods mentioned previously. The ratio difference method was carried out at wavelengths of 294.6 nm and 265.6 nm for OFL, 292 nm and 315 nm for ORN. The linear range was (2-15 µg/mL) for OFL and (3-30 µg/mL) for ORN. The MCR method based on the use of mean centered ratio spectra in dual steps and calculating the second ratio spectra mean centered values at 294.6 nm for OFL and 315 nm for ORN. The continuous wavelet transformation which carried out using MATLAB at wavelengths of 265 nm for OFL and 306 for ORN. These techniques were intended for the binary mixture analysis in bulk powder and pharmaceutical formulations with high recoveries. The developed methods were validated according to ICH guidelines. All techniques were statistically compared to either an official method for OFL or a reported method for ORN and the results indicate that there were not any significant differences.

Ecofriendly chromatographic estimation of spasmolytic pharmaceutical mixture along with official toxic impurity, 3,5-dichloroaniline: Complete green profile appraisal.

Nowadays, Green Analytical Chemistry is widely applied to provide various analytical methods with eco-friendly procedures employing the least toxic, harmful reagents on humans and the environment without affecting the efficacy of the determination. Accordingly, two eco-friendly, accurate, and reliable high-performance thin-layer chromatography-densitometry and high-performance liquid chromatographic methods were established for the determination and separation of two antispasmodic drugs, namely phloroglucinol and trimethylphloroglucinol in their pure, combined dosage form along with phloroglucinol toxic impurity, 3,5-dichloroaniline. For high-performance thin-layer chromatography-densitometry, efficient separation was developed via utilizing the stationary phase of high-performance thin-layer chromatography silica gel 60 F254 plates and developing a system comprising of ethyl acetate-butanol-ammonia in the ratio of 8.0:2.0:0.2, by volume and scanning of the developed bands at 210.0 nm. The subsequent method is isocratic high-performance liquid chromatography with diode array detection in which separation was successively attained using XTerra RP-C18 (250 × 4.6 mm, 5 µm) column as stationary phase and methanol-10.0 mM phosphate buffer, pH 3.7 ± 0.1 as mobile phase in the ratio of 75.0:25.0, v/v at flow rate 1.0 ml/min and scanning at 220.0 nm. The developed liquid chromatography methods were validated according to the International Council for Harmonization guidelines, and all results acknowledged their efficacy. Additionally, the proposed methods worked well for assessing the cited drugs in binary combined commercially available pharmaceutical formulation. The greenness profile of the present methods was assessed and estimated using various assessment tools, namely; Green Analytical Procedure Index, analytical eco-scale method, National Environmental Method Index in addition to Analytical GREEnness tool to evaluate the greenness of the provided methods with a statistical comparison between them to assess the more green ones.

Smart stability indicating spectrophotometric methods for determination of modafinil: the promising treatment for post-covid neurological syndrome.

Modafinil (MDF) is one of the neurostimulants with a potential effect in the COVID-19 ICU ventilated patients and post-COVID neurological syndrome treatment. Four rapid, simple and cost-effective stability indicating spectrophotometric methods were used for estimation of MDF in the presence of its acidic degradation product, namely; ratio difference (RD), first derivative of the ratio spectra (1DD), mean centering (MCR) and ratio subtraction method (RS). These methods were validated according to ICH guidelines and all methods revealed a good linearity in concentration range of (5-30 µg/mL) in addition to a good accuracy and precision with mean percentage recovery of 99.97 ± 0.305 for (RD), 100.10 ± 0.560 for (1DD), 100.02 ± 0.483 for (MCR) & 99.18 ± 1.145 for (RS) method. Specificity of the proposed methods was assessed and MDF was determined in the presence of up to 80% of its acidic degradation product for RD, 1DD, MCR and RS methods. The proposed methods were successfully applied for the determination of MDF in bulk powder and its tablet dosage form with mean percentage recovery of 100.33 ± 0.915 for (RD), 100.62 ± 0.985 for (1DD), 99.70 ± 0.379 for (MCR) and 100.21 ± 0.313 for (RS) method. The results obtained were statistically compared with those of official HPLC method and showed no significant difference with relevance accuracy and precision.

Sustainable spectrophotometric determination of antihypertensive medicines reducing COVID-19 risk via paired wavelength data processing technique - Assessment of purity, greenness and whiteness.

Recent studies have reported that using certain antihypertensive therapies such as angiotensin II receptor blockers (ARBs) is associated with mitigation of fatal outcomes and enhancing clinical features of patients having hypertension during coronavirus pandemic. Thus, in the current work an innovative, effective, white and sustainable spectrophotometric technique called paired wavelength data processing technique (PWDPT) was developed for evaluation of recommended antihypertensive combination therapies incorporating candesartan cilexetil (CAN) and hydrochlorothiazide (HCT). This technique included three methods, namely, absorbance resolution (AR), amplitude resolution (PR) and ratio extraction (RE). Linearity ranges were (5.0 µg/mL - 50.0 µg/mL) and (2.0 µg/mL - 24.0 µg/mL) for CAN and HCT, respectively. Validation and confirmation of all suggested methods were conducted in accordance with ICH guidelines, producing satisfactory results within the accepted limits. Statistical comparison was achieved between the attained results from suggested methods and those attained from official methods, in which insignificant difference was existed. The suggested methods were successfully employed for identification of the studied drugs as well as determination of their spectral recognition and evaluation of the purity in their combined formulations. The proposed methods followed the principles of green analytical chemistry, where their greenness was evaluated and compared with the official potentiometric and HPLC methods via using four tools, namely, National Environmental Methods Index (NEMI), the Analytical Eco-Scale, the Green Analytical Procedure Index (GAPI) and Analytical greenness metric (AGREE) which affirmed the eco-friendly nature of the proposed methods. Moreover, studying the whiteness features was performed using the recently introduced RGB12 model. The acceptable results along with the sustainability, simplicity, affordability and low-cost of the proposed methods encourages their utilization in the quality control laboratories.

Novel Spectrophotometric Approaches for the Simultaneous Quantification of Ternary Common Cold Mixture Containing Paracetamol with a Challenging Formulation Ratio: Greenness Profile Evaluation.

BACKGROUND: Common cold and cough preparations represent a huge segment of the global pharmaceutical market. Recently, cold/cough formulations containing paracetamol (PAR) have attracted significant attention as PAR has been implemented into the supportive treatment of mild cases of COVID-19 as the first-line antipyretic. From a literature review, no method has been reported yet for simultaneous estimation of PAR, pseudoephedrine hydrochloride (PSE) and carbinoxamine maleate (CRX) in any matrix. Thus, there is an urgent need for smart and green methods that would enable quantification of the cited components in their challenging ratio. OBJECTIVES: The aim of this work is to develop and validate the first UV spectrophotometric methods for simultaneous determination of the selected drugs taking into consideration the list of challenges including the highly overlapping features and spectral interferences in the cited mixture. METHODS: Namely, the proposed methods are: direct spectrophotometry, dual wavelength, first derivative, derivative ratio, ratio difference, constant center coupled with spectrum subtraction, and the constant multiplication method paired with spectrum subtraction. RESULTS: These methods were linear over the concentration range of 2.5-35, 1.5-20, and 4.5-35 µg/mL for PAR, PSE and CRX, respectively. These methods fulfill the validity parameters according to International Conference on Harmonization (ICH) guidelines. The results obtained were statistically benchmarked to the official ones where no significant difference was noticed. CONCLUSION: The developed methods are successfully applied for concurrent quantification of the studied components in the marketed dosage form without interference from matrix excipients. The impact on the environment was assessed by five green metrics, namely a recent Analytical greenness (AGREE) metric algorithm based on the green analytical chemistry framework, Green Analytical Procedure Index (GAPI), Eco-Scale, Assessment of Green Profile (AGP), and National Environmental Methods Index (NEMI). HIGHLIGHTS: Eco-friendly and successive spectrophotometric methods were firstly developed in this work, for the simultaneous quantification of PAR, PSE and CRX. These approaches incorporate a simple enrichment-aided technique to augment their spectrophotometric signals, facilitating the accurate quantitation of the minor component in the cited mixture.

Advanced Spectrophotometric Resolution Techniques for a Spectrally Overlapping Spasmolytic Binary Mixture along with Dichloroaniline as a Toxic Impurity: Application to Content Uniformity Testing.

BACKGROUND: Irritable bowel syndrome (IBS) is a common disorder leading to undesirable pain. Phloroglucinol (PHG) and trimethylphloroglucinol (TMG) are co-formulated as spasmolytic medication that is considered to be effective in reducing smooth muscle spasm. 3,5-Dichloroaniline (DCL) is a specified PHG pharmacopoeial impurity which needs to be monitored to avoid its toxic effects. OBJECTIVE: Different smart approaches are presented to provide simple, reliable, and economic spectrophotometric methods able to resolve the severe overlap in the spectra of PHG and TMG in their pure and pharmaceutical forms, in addition to their estimation in the presence of DCL as a toxic impurity of PHG without any need for initial separation. METHODS: The presented work includes univariate methods, derivative ratio (DR), ratio difference (RD), mean centering (MCR) and deconvulated Fourier method (DF), which were able to determine PHG and TMG simultaneously in their binary mixture. Firstly, DCL was estimated in the zero order, where the two drugs have zero absorption at 247.0 nm, and then its contribution was eliminated by applying ratio subtraction method. Multivariate chemometric partial least squares (PLS) and principal component regression (PCR) models were also applied to determine PHG and TMG simultaneously in the presence of the impurity, DCL. RESULTS: Univariate methods were applied in the range 5.0-30.0, 2.5-25.0, and 1.0-12.0 µg/mL for PHG, TMG, and DCL, respectively. The proposed chemometric models were used in the range 6.0-14.0, 5.0-25.0 and 2.0-10.0 µg/mL for PHG, TMG, and DCL, respectively. These analytical approaches succeeded in estimating the cited drugs in their pharmaceutical formulation and assessing content uniformity of dosage units. The methods were statistically compared with a reported HPLC method, and the results revealed no significance statistical difference. CONCLUSION: This work provides for the first time successful univariate and multivariate PLS and PCR methods to assess PHG and TMG in the presence of DCL as a toxic impurity along with content uniformity testing of dosage units. HIGHLIGHTS: Comparative univariate and multivariate spectrophotometric analytical approaches are presented, for the first time, for estimation of spasmolytic formulation of PHG and TMG in the presence of DCL as a PHG toxic impurity. Successful application to content uniformity testing of Stopspasm® dosage form is demonstrated. A statistical study, including t-tests and one-way analysis of variance (ANOVA), was conducted.

Eco-friendly spectrophotometric evaluation of triple-combination therapies in the treatment strategy of patients suffering from hypertension during coronavirus pandemic - Spectralprint recognition study.

Recent studies have reported that using certain antihypertensive therapies such as angiotensin II receptor blockers (ARBs) and calcium channel blocker (CCBs) is associated with reduction of fatal outcomes and improving clinical characteristics of patients suffering from hypertension during coronavirus pandemic. Thus, in the current work an effective, innovative and eco-friendly spectrophotometric manner namely, parent spectrum extraction (PSE)was established for evaluation of recommended triple antihypertensive combination therapies incorporate valsartan (VAL) as ARBs, amlodipine besylate as CCBs (AML) and hydrochlorothiazide (HCT)as diuretic into single-pill in challengeable ratio. PSE manner composed of two complementary steps, auxiliary resolution coupled with data analysis resolution(DAR)and it is characterized by resolving the spectral bands of the drugs and extraction of their discrete parent spectra (D0); accordingly, enabling determination of each analyte at its λmax. Auxiliary resolution of AML in triple mixture was applied to decrease complexity of overlapped spectra via constant multiplication (CM) followed by spectrum subtraction (SS) to obtain resolved mixture of VAL and HCT while data analysis resolution (DAR) of this binary mixture was applied via one of three novel methods namely, absorbance extraction (AE), peak-amplitude extraction (PE) and ratio extraction (RE) along with SS method. The proposed methods had analyzed VAL, AML and HCT in the range of 4.0-44.0 µg/mL, 4.0-40.0 µg/mL and 2.0-24.0 µg/mL, respectively with an excellent correlation coefficient (r ≥ 0.9999). Further, the proposed methods in PSR manner were validated as stated by ICH guidelines and it was found that accuracy and precision results are within the acceptable limit. The suggested procedures were effectively utilized for the concurrent quantification of VAL, AML and HCT in synthetic mixtures and tablets. The greenness of the proposed spectrophotometric methods was evaluated by National Environmental Methods Index (NEMI), the Analytical Eco-Scale, the Green Analytical Procedure Index (GAPI) and Analytical greenness metric (AGREE) where the four tools affirmed the eco-friendly nature of the proposed methods. A comparison between the outcomes of the studied methods with the official and reported ones was performed and no statistical difference was arisen between the methods regarding to accuracy and precision.The achieved results along with the simplicity, affordability and low-cost of the proposed methods recommended their appropriateness for the regular quality control examination and analysis of pure materials and pharmaceutical formulations as well as their applicability for the spectralprint recognition of the studied drugs.

Systemic Optimization and Validation of Normal and Reversed-Phase Eco-Friendly Chromatographic Methods for Simultaneous Determination of Paracetamol and Phenylephrine Hydrochloride in the Presence of Paracetamol Impurities.

BACKGROUND: Chromatographic behavior of different substances in normal and reversed phases is an interesting area in the scientific community. OBJECTIVE: The work aimed to optimize and validate chromatographic separation methods for simultaneous determination of paracetamol (PAR) and phenylephrine HCl (PHE) in the presence of PAR impurities, namely p-aminophenol, p-nitrophenol, acetanilide, and p-chloroacetanilide with further quantification of these toxic impurities. METHODS: TLC method based on normal phase separation was carried out on aluminum sheets of silica gel 60 F254 using ethanol:chloroform:ammonia as a developing system, followed by densitometric measurements. While HPLC is based on reversed phase separation using a C18 column against acetonitrile:phosphate buffer pH 5 as a mobile phase. RESULTS: PAR and PHE were determined by the TLC-densitometric method in concentration ranges of 3-25 and 0.1-3 µg/band, respectively, and determined by the HPLC method over concentration ranges of 5-400 and 2-80 µg/mL, respectively. Both methods were optimized and validated. Furthermore, they were successfully applied for pharmaceutical formulations with precision <2%. Moreover, results of a statistical comparison with the official methods confirm the methods' validity claims. CONCLUSION: Two eco-friendly chromatographic methods were developed to determine PAR and PHE in their binary mixtures, pharmaceutical formulations, and in the presence of PAR-related impurities with further quantification of these toxic impurities. HIGHLIGHTS: These simple chromatographic methods are the first methods developed for simultaneous determination of PAR and PHE in the presence of PAR-related impurities.

Greenness Assessment of Two Validated Stability-Indicating Chromatographic Methods for Estimating Modafinil Using the Analytical Eco-Scale.

BACKGROUND: Modafinil (MDF) is one of the drugs used for the treatment of narcolepsy. OBJECTIVE: This manuscript describes the development and validation of two chromatographic stability-indicating methods for MDF in the presence of its acid-induced degradation product. METHODS: MDF was degraded under different stress conditions and identification of the degradation product was performed using IR and mass spectroscopy. The first method involved TLC, in which plates precoated with silica gel G60 F254 were used and the developing system was dichloromethane- methanol (9:1, v/v). The second method was an eco-friendly (HPLC) method that utilized a C-18 column and ethanol-H2O (30:70, v/v) as a mobile phase with a flow rate of 1 mL/min and UV detection at 220 nm. RESULTS: Good linear relationships were obtained within the ranges 1-10 µg/band and 2-10 µg/mL for TLC-densitometry and HPLC, respectively. The obtained results were statistically compared with those of the official HPLC method and showed no significant difference with respect to their accuracy and precision at P = 0.05. Greenness scores represent excellent green analysis results in comparison with the reported studies. CONCLUSIONS: The proposed methods were validated according to ICH guidelines and were applied on bulk powder and pharmaceutical dosage forms using eco-friendly mobile phases in line with worldwide trends. HIGHLIGHTS: Chromatographic methods have been validated for the estimation of MDF in the presence of its degradation product. Clarification of the degradation pathway and elucidation of the structure were stated for the first time. This is the first published method using greenness assessment metrics for the analysis of MDF.

Chemometric quality assessment of Paracetamol and Phenylephrine Hydrochloride with Paracetamol impurities; comparative UV-spectrophotometric implementation of four predictive models.

Spectrophotometric data analysis using multivariate approaches has many useful applications. One of these applications is the analysis of active ingredients in presence of impurities. Four chemometric-assisted spectrophotometric methods, namely, principal component regression (PCR), partial least-squares (PLS), artificial neural networks (ANN) and multivariate curve resolution-alternating least squares (MCR-ALS) were proposed and validated. The developed chemometric methods were compared to resolve the severely overlapped spectrum of Paracetamol (PAR) and Phenylephrine HCl (PHE) along with PAR impurities namely, P-Aminophenol (PAP), P-Nitrophenol (PNP), Acetanilide (ACT) and P-Chloroacetanilide (CAC). The four multivariate calibration methods succeeded in simultaneous determination of PAR and PHE with further quantification of PAR impurities. So, the proposed methods could be used with no need of any separation step and successfully applied for pharmaceutical formulation analysis. Furthermore, statistical comparison between the results obtained by the proposed chemometric methods and the official ones showed no significant differences.

Capillary zone electrophoresis as a quality assessment tool of paracetamol and phenylephrine hydrochloride in presence of paracetamol impurities.

The combination of paracetamol (PAR) and phenylephrine HCl (PHE) is a common pharmaceutical combination intended to manage symptoms of every day cold. Since paracetamol is susceptible to degradation or some manufacturing-related impurities, its stability should be monitored continuously. The developed method in this study for the determination of PAR and PHE in presence of PAR impurities is considered a quality assessment tool especially when PAR impurities can be quantitatively determined. A capillary zone electrophoresis (CZE) method was optimized and validated for simultaneous determination of PAR and PHE in presence of PAR impurities namely, p-Aminophenol (PAP), p-Nitrophenol (PNP), Acetanilide (ACT) and p-Chloroacetanilide (CAC) with further quantification of these toxic impurities. Factors that affect the separation quality such as pH, buffer and applied voltage were optimized. The separation was carried out using 20 mM phosphate buffer (pH 8). The linearity was reached over concentration ranges of 30-250 µg/mL, 1-40 µg/mL, 2-50 µg/mL, 2-50 µg/mL, 2-50 µg/mL and 2-50 µg/mL for PAR, PHE, PAP, PNP, ACT, and CAC, respectively, with accuracy ranging from 99.06% to 100.62%. After validation, the method was applied for pharmaceutical formulation analysis with RSD <2%. Moreover, statistical comparison with the official methods confirms that the method is a viable alternative for quality assessment of this combination.

Chromatographic estimation of a novel triple-therapy combination targeting Helicobacter pylori eradication in different matrices.

Aim: Helicobacter pylori infection is a prevalent global bacterial infection that can potentially exaggerate symptoms of other serious infections like SARS-CoV-2 (COVID-19). Methodology: Herein, an efficient, accurate and cost-effective high-performance liquid chromatography-diode array detector method was developed and validated for determination of the novel triple therapy combination of tinidazole (TD), clarithromycin (CLR) and lansoprazole (LAN) in different analytical matrices (pharmaceutical formulation, dissolution media and spiked human plasma). Results: Successful chromatographic separation was achieved using Agilent Microsorb-MV 100-5 CN column (250 × 4.6 mm, 5 µm) and a mobile phase consisted of acetonitrile and 10.0 mM phosphate buffer, pH 7.5 ± 0.1 at flow rate of 1 ml/min via gradient elution. UV-detection was accomplished at 210.0 nm for CLR and 290.0 nm for TD and LAN. Conclusion: The developed method clearly provides a reliable, beneficial and cost-effective tool for quality control, dissolution testing and biological applications of the mentioned drugs.

Spectral manipulation of ratio data for simultaneous determination of binary mixture of Paracetamol and Phenylephrine Hydrochloride.

Three ratio spectra manipulating spectrophotometric methods have been developed for determination of Paracetamol (PAR) and Phenylephrine HCl (PHE) in bulk powder and in pharmaceutical formulation. Linear correlations were obtained over the concentration range of 1.0-25.0 µg/mL and 5.0-50.0 µg/mL for PAR and PHE, respectively. The first method is the ratio subtraction method (RS) coupled with constant multiplication (CM) in which PHE was determined by ratio subtraction and PAR was determined by constant multiplication. The second method is the ratio difference method (RD) which depends on measuring the difference between the amplitudes of the ratio spectra at two selected wavelengths. The third method is the first derivative of the ratio spectra (1DD), which allows the determination of PAR at 238.8 and 243 nm and PHE at 213.2, 222.2, 271.8 and 286 nm. The proposed methods are simple, accurate and precise (RSD does not exceed 2%). The applicability of the proposed methods was successfully verified by the analysis of PAR and PHE in pharmaceutical formulation without interference of the dosage form additives. Furthermore, the developed methods were validated according to ICH guidelines, so they are considered to be potential competitors for the analysis of the mixture in quality control labs and pharmaceutical factories.

When is it safe to eat different broiler chicken tissues after administration of doxycycline and tylosin mixture?

Residues of veterinary drugs in poultry meat have serious health effects on humans (e.g., antimicrobial resistance, carcinogenicity, and hypersensitivity), which make the control of veterinary drug residues an important parameter in ensuring consumer protection.  This work was performed to quantitatively determine two co-formulated anti-infective veterinary agents, tylosin tartrate (TYT) and doxycycline hydrochloride (DOX) in different tissues of broiler chickens (liver, muscles, and fat) using high performance liquid chromatography. The chicken was treated with the recommended dose of a binary mixture of the drugs (Tydovet). Moreover, the study aimed to estimate the withdrawal time of both drugs in chicken tissues. The analysis was done by solvent extraction and solid-phase extraction for clean-up of samples from the tissue matrix, followed by liquid chromatographic determination of the cited drugs with UV-detection. Residue decline with time was tracked, and both antibiotics were found to be more persistent in liver tissues than other tissues (muscle and fat). The effect of freezing and cooking was investigated on tissue residue levels. While freezing had little effect on the concentration of both antibiotics; cooking, as anticipated, led to a marked decline. Therefore, it is recommended to pay attention to the proper withdrawal periods before marketing to ensure the hygienic suitability of broilers edibles for safe human consumption. PRACTICAL APPLICATION: This novel study measures tylosin and doxycycline residues simultaneously in different tissues (muscle, fat, and liver) after administration of Tydovet powder to the broiler chicken. Residues in fat persisted for a longer time than in muscle in case of TYT, whereas the reverse was noticed in DOX.