Development of Response Surface Approach for Determination of Paracetamol, Chlorpheniramine Maleate, Caffeine and Ascorbic Acid by Green HPLC Method: A Desirability-Based Optimization.

Design of experiment is an efficient and cost-effective tool to optimize the chromatographic separation of a multicomponent mixture. The central composite design was conducted to develop and optimize a green high performance liquid chromatography (HPLC) method for simultaneous quantitation of a quaternary mixture of paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid in their pharmaceutical dosage form as well as the determination of their dissolution profile. A five-level three-factor model was performed to investigate the effect of mobile phase composition, pH and flow rate on enhanced resolution and short run time. Analysis was performed using a Kinitex EVO C18 column and a mobile phase composed of methanol: 0.02 M phosphate buffer pH 3.3 (34:66, v/v) at 1.0 mL/min using photodiode array detection. Optimum chromatographic separation was achieved in <6 min with a desirability of 0.999. Linearity was achieved over a range of 1.00-300.00, 1.00-50.00, 2.00-50.00 and 2.00-100.00 µg/mL for paracetamol, chlorpheniramine maleate, caffeine and ascorbic acid, respectively, with a limit of detection (<0.1 µg/mL). The greenness profile was evaluated using the analytical eco-scale and Analytical GREEnness Metric Approach with values of 81 and 0.77, respectively.

Application of smart chemometric models for spectra resolution and determination of challenging multi-action quaternary mixture: statistical comparison with greenness assessment.

A multivariate spectrophotometric method is a potential approach that enables discrimination of spectra of components in complex matrices (e.g., pharmaceutical formulation) serving as a substitution method for chromatography. Four green smart multivariate spectrophotometric models were proposed and validated, including principal component regression (PCR), partial least-squares (PLS), multivariate curve resolution-alternating least squares (MCR-ALS), and artificial neural networks (ANN). The developed chemometric models were compared to resolve highly overlapping spectra of Paracetamol (PARA), Chlorpheniramine maleate (CPM), Caffeine (CAF), and Ascorbic acid (ASC). The four multivariate calibration models were assessed via recoveries percent, and root mean square error of prediction. Hence, the proposed models were efficiently applied with no need for any preliminary separation step. The models were utilized to analyze the studied components in their combined pharmaceutical formulation (Grippostad® C capsules). Analytical GREEnness Metric Approach (AGREE) and eco-scale tools were applied to assess the greenness of the established models and found to be 0.77 and 85, respectively. Moreover, the proposed models have been compared to official ones showing no considerable variations in accuracy and precision. Therefore, these models can be highly advantageous for conducting standard pharmaceutical analysis of the substances researched within product testing laboratories.

Design of screen-printed potentiometric platform for sensitive determination of mirabegron in spiked human plasma; molecular docking and transducer optimization.

The integration of molecular modelling simulation and electrochemical sensors is of high interest. Herein, for the first time, a portable solid-contact potentiometric electrode was designed for the sensitive determination of mirabegron (MIR) in human plasma and pharmaceutical formulation. A two-step optimization protocol was investigated for the fabrication of an ion on sensing polymeric membrane. First, molecular docking was used for optimum ionophore selection. Calix[6]arene showed the highest affinity towards MIR with a better docking score (-4.35) and potential energy (-65.23) compared to other calixarene derivatives. Second, carbon nanotubes and gold nanoparticles were investigated as ion-electron transducers using a drop-casting procedure. Gold nanoparticle-based sensors showed better slope, potential stability, and rapid response compared to carbon nanotubes. The proposed solid contact sensors (V-VII) showed comparable sensitivity and ease of handling compared to liquid contact sensors (I-IV). The optimized gold nanoparticles sensor VII produced a Nernstian response over the range of 9.77 × 10-7 to 1 × 10-3 M with LOD of 2.4 × 10-7 M. It has also been used to determine MIR in its pharmaceutical formulation in the presence of a co-formulated antioxidant butylated hydroxytoluene and spiked human plasma. This would offer a feasible and economic platform for monitoring MIR in pharmaceutical preparation and biological fluids.

Development of Different Separation Techniques for Impurity Profiling of Neostigmine Methylsulfate: A Comparative Study.

Different separation techniques have been employed to resolve mixtures of multicomponent preparations over the last few decades. They could be efficiently applied for impurity profiling of active drug substances. Impurity profiling has become a critical procedure in pharmaceutical companies to comply with numerous regulatory standards. Isolation and characterization of impurities are crucial for obtaining data that proves biological safety and efficacy. In this contribution, different HPLC, capillary electrophoresis (CE) and TLC-densitometric methods were developed for the determination of neostigmine methylsulfate (NEO) along with 3-hydroxyphenyltrimethyl ammonium methylsulfate (3-HPA) and 3-dimethylaminophenol (DAP) as its impurities in the presence of citric acid. The linearity for NEO was attained in the range of 5-120 µg/mL and 10-60 µg/mL for the HPLC and CE methods, respectively. Regarding the impurities, linearity was obtained over the range of 10-30 µg/mL for 3-HPA and 5-30 µg/mL for DAP in the two proposed methods. For the TLC method, NEO and DAP were determined within the range of 1-11 µg/band, whereas 3-HPA was assayed over the range of 2-12 µg/band. The suggested methods can be securely utilized for routine analysis of the cited components in 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.

Different Approaches in Manipulating Ratio Spectra for Analyzing Amlodipine Besylate and Irbesartan Combination.

BACKGROUND: Hypertension is a key risk factor for ischemic heart disease and atherosclerosis. Most patients require a combination of antihypertensive medications to accomplish their therapeutic goals. Antihypertensive medicines such as calcium channel blockers and angiotensin receptor blockers are indicated for patients whose high blood pressure cannot be controlled with monotherapy. The combination of amlodipine besylate (AML) with irbesartan (IRB) is an example of this synergistic activity in lowering blood pressure. OBJECTIVE: In this regard, the goal of the research is to develop sensitive spectrophotometric methods for the simultaneous determination of amlodipine besylate and irbesartan. METHODS: Three simple ratio spectra-manipulating spectrophotometric methods namely, ratio difference, mean centering of ratio spectra, and derivative ratio, were developed for the simultaneous assay of the cited mixture. RESULTS: Linear correlations were attained over the concentration range of 1-35 µg/mL and 2-35 µg/mL for amlodipine besylate and irbesartan, respectively. The methods were validated according to the International Conference on Harmonization guidelines with good results. CONCLUSION: The methods developed were successfully applied for the assay of the cited drugs in their marketed formulation. They could be efficiently used for routine analysis of the mentioned drugs in QC laboratories. HIGHLIGHTS: The proposed approaches do not require expensive solvents or complex instruments. They could be used in routine laboratory tests where time and cost are crucial.

Validated Smart Different Chromatographic Methods for Selective Quantification of Acefylline Piperazine, Phenobarbital Sodium and Methylparaben Additive in Bulk and Pharmaceutical Dosage Form.

Two chromatographic methods have been proposed for the simultaneous determination of acefylline piperazine (ACEF) and phenobarbital (PHENO) in presence of methylparaben as additive in pharmaceutical dosage form. The first method was thin-layer chromatography. The separation was achieved using silica gel as stationary phase and chloroform: methanol: glacial acetic acid (2.0, 8.0 and 0.1, by volume) as a developing system at 254 nm. Accurate determination of both drugs was attained over the concentration range of 0.5-25 µg/band. The second method was based on the use of reversed phase liquid chromatography with diode array detection, by which the proposed components were separated on a reversed phase C18 analytical column using methanol: water (60: 40, by volume) as a mobile phase with flow rate of 0.8 mL/min at 214 nm in a concentration range of 0.5-100 µg/mL. The proposed chromatographic methods were practiced successfully for the determination of ACEF and PHENO in pharmaceutical dosage form. Both methods were validated according to the International Conference on Harmonization guidelines and statistically compared with a reported high-performance liquid chromatograph method. Planar chromatography has never been proposed in the literature for ACEF and PHENO determination besides the proposed columnar chromatographic method using an isocratic eco-friendly mobile phase.

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.

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.

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.

Utility of Single-Photon Emission Computed Tomography/Computed Tomography in Suspected Unilateral Condylar Hyperplasia: A Histopathologic Validation Study.

PURPOSE: The purpose of this study is to evaluate the utility of hybrid single-photon emission computed tomography (SPECT) and computed tomography (CT) with technetium-99m methylene diphosphonate in patients with suspected active unilateral condylar hyperplasia (UCH) using histopathology as the reference standard. METHODS: Twenty-four patients with suspected active UCH prospectively underwent technetium-99m methylene diphosphonate planar bone scintigraphy with SPECT/CT of the mandible. Qualitative and quantitative readings for growth activity were performed by 3 nuclear medicine physicians and the final diagnosis was derived from postoperative histopathological examination. Readings were reported as positive, equivocal, or negative. Total, maximum, and mean counts were recorded for each condyle on SPECT/CT images. The uptake of the index (suspected) condyle was expressed as a count ratio (Rtotal, Rmean, Rmax), a percentage uptake (Ptotal, Pmean, Pmax), background-corrected counts (Btotal, Bmean, Bmax), as well as CT-based condylar diameters (RCT,PCT) relative to the contralateral condyle. RESULTS: Interobserver agreement was 0.79 and 0.83 for planar bone scintigraphy and SPECT/CT, respectively, with a total of 5 and 1 equivocal readings from the respective modalities. Surgery was performed in 22 patients; all of them had pathologically proven UCH. SPECT/CT was slightly more sensitive than planar bone scintigraphy (91 vs 78%) with identical specificity (96%). Rtotal, Rmean, Ptotal, and Pmean demonstrated area under the curve between 84% and 86%. Metrics based on CT diameters and background-corrected counts were not associated with UCH diagnosis. CONCLUSIONS: Quantitative approaches based on total or mean count ratio or relative count percentage were equally predictive for UCH diagnosis; however, they were slightly less sensitive compared with qualitative technetium-99m methylene diphosphonate SPECT/CT evaluation. SPECT/CT evaluation has the potential to decrease the equivocal readings.

Do BRAFV600E mutation and sodium-iodide symporter expression affect the response to radioactive iodine therapy in patients with papillary thyroid carcinoma?

OBJECTIVE: To report on the associations between BRAF and sodium iodide symporter expressions and treatment outcomes in patients with papillary thyroid carcinoma. METHODS: Inclusion criteria included a pathologic diagnosis of papillary thyroid carcinoma of any stage, thyroidectomy followed by radioactive iodine therapy, and follow-up for at least 12 months after initial therapy. Events were classified as persistent or recurrent disease based on a clinical or investigational evidence of disease within or after, respectively, 1 year from initial therapy. Disease-free survival was calculated between the dates of surgery and confirmed event. Patients with no evidence of disease were censored at their last follow-up (censored group). BRAF mutation and sodium-iodide symporter expressions were evaluated using immunohistochemistry. RESULTS: The study included 78 patients (60 females, 18 males) with median age 36 years (range: 20-70 years). BRAF was positive in 78%, equivocal in 13%, and negative in 9%. Sodium-iodide symporter was positive in 88%. BRAF mutation was significantly associated with increasing tumor size, presence of lymphovascular invasion, classic subtype of papillary thyroid carcinoma, thyroid capsular infiltration, and lymph node metastasis. Sodium-iodide symporter expression was not associated with any clinical or pathologic characteristics. Patients with negative or equivocal BRAF had significantly better disease-free survival (82%, 3 events) compared to the positive group (41%, 33 events; P=0.02). CONCLUSION: In patients with papillary thyroid carcinoma, BRAF mutation is associated with high-risk pathological characteristics and worsened disease-free survival.

Development and Validation of Eco-Friendly Liquid Chromatographic and Spectrophotometric Methods for Simultaneous Determination of Coformulated Drugs: Phenylephrine Hydrochloride and Prednisolone Acetate.

Five simple, sensitive, and eco-friendly LC and UV spectrophotometric methods have been developed for the simultaneous determination of phenylephrine hydrochloride (PHE) and prednisolone acetate (PRD) in their combined dosage form. The first method was reversed-phase (RP) LC using methanol-water-heptane-1-sulfonic acid sodium salt (75 + 25 + 0.1, v/v/w) as a mobile phase. Separation was achieved using an XSelect HSS reversed-phase C18 analytical column (250 × 4.6 mm, 5µm). The flow rate was 1.0 mL/min and UV detection was done at 230 nm. Quantification was achieved over the concentration ranges of 5-50 µg/mL for PHE and 2-90 µg/mL for PRD. Four spectrophotometric methods were proposed, namely dual wavelength, first derivative of ratio spectra, ratio difference, and mean-centering of ratio spectra. Linearity was observed in the concentration ranges of 10-120 and 5-35 µg/mL for PHE and PRD, respectively, for the spectrophotometric methods. Green solvents were used in the proposed methods because they play a vital role in the analytical methods' influence on the environment. The suggested methods were validated regarding linearity, accuracy, and precision according to the International Conference on Harmonization guidelines, with satisfactory results. These methods could be used as harmless substitutes for routine analysis of the mentioned drugs, with no interference from excipients.

Stability-indicating spectrofluorometric method for the determination of some cephalosporin drugs via their degradation products.

A stability-indicating spectrofluorometric method was investigated for the determination of three cephalosporin drugs, namely, cefpodoxime proxetil (CPD), cefixime trihydrate (CFX), and cefepime hydrochloride (CPM), via their acid and alkali degradation products. The three drugs were determined via their acid degradation at 432, 422, and 435 nm using an excitation wavelength of 310, 330, and 307 nm for CPD, CFX, and CPM determination, respectively, and via their alkali degradation at 407, 411, and 405 nm using an excitation wavelength of 310, 305, and 297 nm for CPD, CFX, and CPM determination, respectively. Linearity was achieved in the ranges of 0.35-3.50, 0.4-4.0, and 0.3-3.0 µg/mL for the acid degradation products of CPD, CFX, and CPM, respectively, and in ranges of 0.05-0.5, 0.1-1.0, and 0.08-0.80 µg/mL for the alkali degradation products of CPD, CFX, and CPM, respectively. The method was validated for various parameters according to International Conference on Harmonization guidelines. The method was successfully applied for the determination of these cephalosporin drugs in pharmaceutical dosage forms with good accuracy and precision. The results obtained by the proposed spectrofluorometric method were compared with good agreement to the official HPLC method.

Validated stability-indicating spectrophotometric methods for the determination of cefixime trihydrate in the presence of its acid and alkali degradation products.

Five simple, accurate, precise, and economical spectrophotometric methods have been developed for the determination of cefixime trihydrate (CFX) in the presence of its acid and alkali degradation products without prior separation. In the first method, second derivative (2D) and first derivative (1D) spectrophotometry was applied to the absorption spectra of CFX and its acid (2D) or alkali (1D) degradation products by measuring the amplitude at 289 and 308 nm, respectively. The second method was a first derivative (1DD) ratio spectrophotometric method where the peak amplitudes were measured at 311 nm in presence of the acid degradation product, and 273 and 306 nm in presence of its alkali degradation product. The third method was ratio subtraction spectrophotometry where the drug is determined at 286 nm in laboratory-prepared mixtures of CFX and its acid or alkali degradation product. The fourth method was based on dual wavelength analysis; two wavelengths were selected at which the absorbances of one component were the same, so wavelengths 209 and 252 nm were used to determine CFX in presence of its acid degradation product and 310 and 321 nm in presence of its alkali degradation product. The fifth method was bivariate spectrophotometric calibration based on four linear regression equations obtained at the wavelengths 231 and 290 nm, and 231 and 285 nm for the binary mixture of CFX with either its acid or alkali degradation product, respectively. The developed methods were successfully applied to the analysis of CFX in laboratory-prepared mixtures and pharmaceutical formulations with good recoveries, and their validation was carried out following the International Conference on Harmonization guidelines. The results obtained were statistically compared with each other and showed no significant difference with respect to accuracy and precision.