Different stability-indicating chromatographic methods for specific determination of paracetamol, dantrolene sodium, their toxic impurities and degradation products

High Performance Thin Layer Chromatography (HPTLC) Analysis of Anti-Asthmatic Combination Therapy in Pharmaceutical Formulation: Assessment of the Method's Greenness and Blueness

A cost-effective, selective, sensitive, and operational TLC-densitometric approach has been adapted for the concurrent assay of Hydroxyzine Hydrochloride (HYX), Ephedrine Hydrochloride (EPH), and Theophylline (THP) in their pure powder and pharmaceutical forms. In the innovative TLC-densitometric approach, HYX, EPH, and THP were efficaciously separated and quantified on a 60F254 silica gel stationary phase with chloroform-ammonium acetate buffer (9.5:0.5, v/v) adjusted to pH 6.5 using ammonia solution as a mobile liquid system and UV detection at 220 nm. The novel TLC method validation has been performed in line with the international conference for harmonization (ICH) standards and has been effectively used for the estimation of the researched medicines in their pharmaceutical formulations without intervention from excipients. Additionally, parameters affecting the chromatographic analysis have been investigated. The new TLC approach's functionality and greenness were appraised using three modern and automated tools, namely the Blue Applicability Grade Index (BAGI), the Analytical Greenness metric (AGREE), and the Green Analytical Procedure Index (GAPI) tools. In short, the greenness characteristics were not achieved as a result of using mandatory, non-ecofriendly solvents such as ammonia and chloroform. On the contrary, the applicability and usefulness of the novel TLC approach were attained via concurrent estimation for the three drugs using simple and straightforward procedures. Moreover, the novel TLC method outperforms previously published HPLC ones in terms of the short run time per sample and moderate pH value for the liquid system. According to the conclusions of comparisons with previously recorded TLC methods, our novel HPTLC method has the highest AGREE score, so it is the greenest HPTLC strategy. Moreover, its functionality and applicability are very appropriate because of the simultaneous assessment of three drugs in one TLC run. Furthermore, no tedious and complicated extraction and evaporation processes are prerequisites.

Ecofriendly single-step HPLC and TLC methods for concurrent analysis of ternary antifungal mixture in their pharmaceutical products

Two accurate, sensitive, and selective methods for simultaneous determination of miconazole nitrate (MIC), nystatin (NYS), and metronidazole (MET) in pure state or drug product were established and verified. First, RP-HPLC-DAD was designed. Separation was accomplished using a ZOBRAX Eclipse Plus RP-C8 column that was running under an isocratic elution of methanol: 0.05% aqueous solution of sodium dodecyl sulphate (40: 60 v/v), with a flow rate that was regulated at 0.8 mL/min. The column temperature was adjusted at 25 °C and diode array detector was monitored at 220 nm. The linearity range of the proposed method was achieved at the concentration of 5-50, 4-50, and 4-40 µg/mL and the attained retention time for the studied drugs was 2.52, 3.52 and 4.99 min for MIC, NYS, and MET, correspondingly. Second, a TLC-densitometric approach was used to resolve the three compounds. Resolution of the three cited drugs was carried out using TLC aluminum plates pre-coated with 0.25 mm silica gel 60 F254. A developing solvent comprised ethyl acetate: toluene: methanol: triethyl amine: formic acid (3: 1: 7: 0.3: 0.1 by volume) (pH = 5.5) was utilized and scanning of the resolved bands at 215 nm. Linearity of the developed TLC method was evaluated and evident to be 0.4-2, 0.4-2.2, and 0.4-2 μg/band for MIC, NYS, and MET, in that order. The suggested chromatographic methods were verified according to ICH directives. The findings of the developed chromatographic procedures were statistically compared with the results of the reported ones using student's t-test and F-test. Furthermore, two green assessment tools evaluated the indicated methods' level of greenness (GAPI and AGREE).

Hydro-organic mobile phase and factorial design application to attain green HPLC method for simultaneous assay of paracetamol and dantrolene sodium in combined capsules

The greenness of any analytical method has become a very important aspect of a good analytical method. However, most chromatographic methods depend on the usage of relatively large amounts of lethal and un-decaying chemicals and solvents. So, a green approach based on the full factorial design was employed to develop a simple and rapid HPLC technique for concurrent determination of paracetamol and dantrolene sodium in their combined capsules. Both drugs are highly recommended to be administered together in patients with severe musculoskeletal disorders. Avoiding the routine methodology and resorting to the modern technology represented in the usage of experimental design allows rapid determination of the studied drugs using the optimum quantity of chemicals to avoid any waste of resources. Simultaneous separation of a binary mixture of paracetamol and dantrolene sodium was accomplished using a reversed phase Hypersil C18 column using an eco-friendly isocratic eluent. The used mobile phase consisted simply of ethanol: water (40:60, v/v). Orthophosphoric acid was used to adjust the pH of the mobile phase to 4.5. Triethanolamine (0.2%) was added aiming to reduce the peak tailing. The assay was completed within less than 6 min adopting 0.8 mL/min as a flow rate. The detection was carried out using a UV-detector at 290 nm. The suggested technique shows a linear correlation over concentration ranges of 1.0-200 and 1.0-40 µg/mL for paracetamol and dantrolene sodium, respectively. The suggested technique allowed the simultaneous analysis of the two co-formulated drugs in their synthetic mixture and combined capsule. The suggested technique is considered a greener substitute for the other reported HPLC techniques through the usage of safer solvents and chemicals, along with decreasing both waste output and analysis time. The method is accurate with recoveries between 97.85 and 101.27%, precise, as %RSD for the intraday and interday precision were between 0.39 and 1.72% and very sensitive with limits of detection (LOD)'s 0.15 and 0.18 µg/ml and limits of quantification (LOQ)'s 0.48 and 0.61 µg/ml for paracetamol and dantrolene sodium, respectively. The method greenness was ensured through its assessment by four greenness metrics. It is also validated following the International Conference on Harmonization Guidelines. The recommended technique could be a good alternative to traditional methods in the routine quality control analysis of the studied drugs due to its minimum harm to the planet or human beings.

Potentiometric Sensor Arrays Based on Hybrid PFSA/CNTs Membranes for the Analysis of UV-Degraded Drugs

The degradation of drugs is a substantial problem since it affects the safety and effectiveness of pharmaceutical products, as well as their influence on the environment. A novel system of three potentiometric cross-sensitive sensors (using the Donnan potential (DP) as an analytical signal) and a reference electrode was developed for the analysis of UV-degraded sulfacetamide drugs. The membranes for DP-sensors were prepared by a casting procedure from a dispersion of perfluorosulfonic acid (PFSA) polymer, containing carbon nanotubes (CNTs), whose surface was preliminarily modified with carboxyl, sulfonic acid, or (3-aminopropyl)trimethoxysilanol groups. A correlation between the sorption and transport properties of the hybrid membranes and cross-sensitivity of the DP-sensor to sulfacetamide, its degradation product, and inorganic ions was revealed. The analysis of the UV-degraded sulfacetamide drugs using the multisensory system based on hybrid membranes with optimized properties did not require a pre-separation of the components. The limits of detection of sulfacetamide, sulfanilamide, and sodium were 1.8 × 10^-7, 5.8 × 10^-7, and 1.8 × 10^-7 M. The relative errors of the determination of the components of the UV-degraded sulfacetamide drugs were 2-3% (at 6-8% relative standard deviation). PFSA/CNT hybrid materials provided the stable work of the sensors for at least one year.

Validated HPLC-PDA methodology utilized for simultaneous determination of Etoricoxib and Paracetamol in the presence of Paracetamol toxic impurities

Etoricoxib (ETO), Paracetamol (PCM), and two toxic impurities for Paracetamol impurity K (4-aminophenol (PAP)) and impurity E (para-hydroxy acetophenone (PHA)) were separated using a simple and selective HPLC method that was tested for the first time. PCM is a commonly used analgesic and antipyretic medication that has recently been incorporated into COVID-19 supportive treatment. Pharmaceuticals containing PCM in combination with other analgesic-antipyretic drugs like ETO help to improve patient compliance. The studied drugs and impurities were separated on a GL Sciences Inertsil ODS-3 (250 × 4.6) mm, 5.0 µm column, and linear gradient elution was performed using 50 mM potassium dihydrogen phosphate adjusted to pH 4.0 with ortho-phosphoric acid and acetonitrile as mobile phase at 2.0 mL/min flow rate at 25 °C and UV detection at 220 nm. The linearity range was 1.5-30.0 µg/mL for ETO and PCM while 0.5-10.0 µg/mL for PAP and PHA, with correlation coefficients (r) for ETO, PCM, PAP, and PHA of 0.9999, 0.9993, 0.9996, and 0.9998, respectively. The proposed method could be used well for routine analysis in quality control laboratory.

Innovative localized surface plasmon resonance sensing technique for a green spectrofluorimetric assay of ketoprofen, paracetamol and chlorzoxazone in pharmaceutical preparations and biological fluids

A green, quick and sensitive spectrofluorimetric technique was investigated and validated for the assay of three different drugs namely, ketoprofen (KPN), paracetamol (PAR), and chlorzoxazone (CLX). The method is based on fluorescence quenching of the fluorescence probe, silver nanoparticles (SNPs). The fluorescence quenching of SNPs may be attributed to the complexation between each of the studied drugs with SNPs. The fluorescence of SNPs alone or after complexation with the studied drugs were measured at 485 nm (λ ex 242 nm) without the need to extract the formed complex. Chemical reduction was employed for preparing SNPs, where silver nitrate was reduced by sodium borohydride in deionized water without adding organic stabilizer. SNPs were found soluble in water, had high stability and had a narrow emission band. The studied drugs were found to decrease the fluorescence of SNPs significantly through static quenching according to Stern-Volmer equation. Factors affecting the reaction between the drugs and NPs were carefully examined and optimized. Using the optimum conditions, the difference in the fluorescence intensity of SNPs before and after complexation with the studied drugs was in a good linear relationship with the concentration of the studied drugs, where (R 2 = 0.9998, 0.9998 and 0.9991) in the ranges of 0.5-5.0, 0.15-3.0 and 0.5-9.0 μg mL-1 for KPN, PAR and CLX, respectively. Validity of the proposed method was investigated according to ICH recommendations. The proposed technique was also employed for the analysis of each of the three drugs in commercial or laboratory prepared tablets and in spiked human plasma with very good recoveries as well as high level of accuracy and precision. This method was intended to the analysis of the proposed drugs in their single formulation and single drug administration. The suggested technique is considered an eco-friendly method, as it uses water as the safest and least expensive solvent. Moreover, the recommended technique does not involve solvent extraction of the formed complexes. Greenness assessment of the suggested procedure was accomplished by applying the four standard assessment tools. Consequently, the recommended method can be used in the routine quality control analysis of the cited drugs with minimum harmful effect on the environment as well as the individuals.

Simultaneous Quantitation of Paracetamol and Lornoxicam in the Presence of Five Related Substances and Toxic Impurities by a Selective HPLC-DAD Method

OBJECTIVE

This research describes the simultaneous quantitation of paracetamol (PRM) and lornoxicam (LRX) with five of their related substances and toxic impurities, including, 4-nitrophenol (NTP), 4-aminophenol (AMP), 4-chloroacetanilide (CAC), N-phenylacetamide (NPA), and 2-aminopyridine (APD) using a specific HPLC-diode array detector (DAD) method.

METHODS

The chromatographic separation involves the use of a XTerra C18 column as the stationary phase and a mobile phase consisting of acetonitrile and 0.025 M phosphate buffer (pH 6). The separation was performed using gradient elution mode at 1.0 mL/min flow rate and detection at 260 nm for the determination of PRM and LRX. For detecting PRM and LRX in the presence of their toxic impurities, 270 nm was used. Validation of the suggested HPLC method was accomplished with regard to linearity, ranges, detection and quantitation limits, robustness, accuracy, precision, and specificity.

RESULTS

Excellent resolution of the mixture components was accomplished at retention times 4.2, 4.8, 7.4, 11.1, 13.5, 14.7, and 15.3 min for APD, AMP, PRM, NPA, LRX, NTP, and CAC, respectively. Linearity was established for PRM and LRX within concentration ranges of 10-100 and 10-60 µg/mL, respectively. The correlation coefficients obtained were >0.9997. The suggested method was confirmed to be a specific stability-indicating through the selective separation of PRM and LRX from their related substances, degradants, and impurities.

CONCLUSION

The proposed method was successfully utilized for the sensitive and selective determination of PRM and LRX in their pharmaceutical formulation.

HIGHLIGHTS

To the best of our knowledge, this is the first impurity profiling assay method for this combination in the presence of five of their toxic related substances and impurities. Taking into consideration that at least two of the studied impurities (AMP and APD) are actually reported degradation products for the main drugs, the suggested method can be considered stability-indicating as well.

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.

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 presence of PAR impurities namely, P-Aminophenol (PAP), P-Nitrophenol (PNP), Acetanilide (ACT) and P-Chloroacetanilide (CAC) with further quantification of these toxic impurities.

METHODS

Thin layer chromatography based on normal phase separation was carried out on aluminum sheet of silica gel 60 F254 using ethanol:chloroform:ammonia as a developing system, followed by densitometric measurements. While, high-performance liquid chromatography (HPLC) is based on reversed phase separation using C18 column against acetonitrile:phosphate buffer pH 5 as a mobile phase.

RESULTS

PAR and PHE were determined by TLC-Densitometric method in concentration ranges of 3 - 25 µg/band and 0.1 - 3 µg/band, respectively and determined by HPLC method over concentration ranges of 5 - 400 µg/mL and 2 - 80 µg/mL for PAR and PHE, respectively. Both methods were optimized and validated. Furthermore, they were successfully applied for pharmaceutical formulations with precision <2%. Moreover, results of statistical comparison with the official methods confirm the claims of methods' validity.

CONCLUSION

Two eco-friendly chromatographic methods were developed to determine PAR and PHE in their binary mixtures, pharmaceutical formulation and in 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 presence of PAR related impurities.

Validated specific HPLC-DAD method for simultaneous estimation of paracetamol and chlorzoxazone in the presence of five of their degradation products and toxic impurities

This work demonstrates a specific and reliable HPLC with diode array detection (DAD) method for the simultaneous estimation of paracetamol (PAR) and chlorzoxazone (CZ) in the presence of five of their degradation products and toxic impurities; namely; 4-aminophenol (AP), 4-nitrophenol (NP), acetanilide (AT), 4-chloroacetanilide (CA) and 2-amino-4-chlorophenol (ACP). Successful chromatographic separation was accomplished using Waters Symmetry C8 column (3.9 × 150 mm, 5 μm) with gradient elution of the mobile phase consisting of 0.05 M phosphate buffer pH 7.5 and methanol. The gradient elution started with 5% (by volume) methanol ramped up linearly to 50% in 10 min, and then maintained at this percentage afterward till the end of the run. The mobile phase was pumped at a flow rate of 1.0 mL/min. The multiple wavelength detector was adjusted at 244 and 285 nm to quantify PAR and CZ, respectively. Additionally, the wavelength 270 nm was found suitable for monitoring the separation of the entire mixture of PAR, CZ, and their impurities. Seven peaks eluted with excellent resolution at retention times 3.4, 5.7, 8.0, 10.1, 10.8, 13.5, and 14.4 min for AP, PAR, NP, AT, ACP, CZ, and CA, respectively. Performance of the proposed method was validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection, and quantitation limits. Calibration curves were linear in the ranges of 10-75 and 10-100 µg/mL for PAR and CZ, respectively with correlation coefficients not less than 0.9998. The proposed method proved to be specific and stability indicating by the resolution of both drugs from their degradation products and toxic impurities. Validated HPLC method was successfully applied to the analysis of PAR and CZ in their combined capsules dosage form, and assay results were favorably compared with a published reference HPLC method. DAD served as an efficient tool for peak identity and purity verification.