Chromatographic analysis of triple cough therapy; bromhexine, guaiafenesin and salbutamol and pharmaceutical impurity: in-silico toxicity profile of drug impurity.

Bromhexine (BR), guaiafenesin (GUF) and salbutamol (SAL) are formulated as Ventocough syrup® (with and without sugar), labeled to contain propyl paraben and sodium benzoate as inactive ingredients. They are used to make coughing more productive and easier. A crucial element and a major issue in the pharmaceutical industry is the control of organic related impurities to obtain safe and effective treatment. Guaiacol (GUL) is reported to be GUF related impurity that was proved to be extremely toxic (toxic rating class 5), and its use should be banned. In this work, In-Silico study and ADMET estimation were conducted to predict GUL pharmacokinetic properties and its toxicity profile. Additionally, two chromatographic methods were conducted to analyze the studied components along with GUF impurity in the presence of the labeled dosage form excipients. The In-Silico study assured that GUL has oral rat acute toxicity and it is considered to be skin sensitizer. On the other hand, the developed TLC- densitometeric method depended on using a mobile phase mixture of hexane: methylene chloride: triethylamine (5.0:6.0:0.3, by volume) as a developing system. UV-Scanning was performed immediately at 275 nm for SAL, GUF and GUL, while scanning at 310 nm was used for scanning BR. Linearity was established in the ranges of 0.25-4.0, 0.25-4.0, 0.5-8.0 and 0.1-1.6 µg/band for BR, SAL, GUF and GUL, respectively. In the developed HPLC method, separation was performed on X-Bridge® C18 column (250 × 4.6 mm, 5 µm) using a solvent mixture of 0.05M disodium hydrogen phosphate pH 3 with aqueous phosphoric acid: methanol (containing 0.3%, v/v triethylamine) (40:60, v/v). Detection was done at 225 nm and separation was achieved within 10 min. Linearity was proved in the range of 2-50 µg/mL for the proposed drugs. Validation of the developed methods was done and all the calculated parameters were within the acceptable limits recommended by ICH guidelines. After that, methods were used to examine the potency of the selected marketed dosage forms and concentrations of all drugs were within the acceptable limits. Additionally, complete separation between the studied drugs and the additives were observed. The developed methods can be used during routine quality control analysis of the proposed drugs when the required issues concern on sensitivity, selectivity and analysis time.

Determination of Gemcitabine and Sorafenib in Spiked Human Plasma Using Multivariate Model Update Chemometric Methods.

BACKGROUND: Gemcitabine (GEM), a pyrimidine nucleoside, has been used as a first-line treatment in non-small-cell lung cancer (NSCLC). Sorafenib (SOR), a nonselective multi-kinase inhibitor, is used as a chemotherapeutic agent in different types of cancers including NSCLC in preclinical studies. Co-administration of GEM and SOR was found to be effective and well-tolerated in the treatment of NSCLC. OBJECTIVE: The aim of the present work is to determine the studied drugs in spiked human plasma simultaneously through resolving the overlapping spectra and removing the interference of the plasma matrix. METHOD: Two updated chemometric models were developed using UV absorbance of the drugs, which named principal component regression (PCR) and partial least-squares (PLS) for determination of GEM and SOR in the ranges of 5-25 and 2-22 µg/mL, respectively. RESULTS: Validation of the two updated models has been achieved in accordance with US Food and Drug Administration (FDA) guidelines, and the results were satisfactory. The two methods had the advantages of high predictive ability of the studied drugs with high precision and accuracy. Moreover, there was no significant difference obtained when statistical comparison was done between the developed and reported methods, showing good validity of the suggested methods. CONCLUSIONS: The two updated models have the advantages of being rapid, accurate, sensitive, and cost-effective for the determination of GEM and SOR in quality control laboratories without any need for initial separation procedures. HIGHLIGHTS: Two updated chemometric methods, PCR and PLS, were developed for the estimation of GEM and SOR in spiked human plasma using their UV absorbance data.

Determination of Bendamustine, Gemcitabine and Vinorelbine (BEGEV) regimen in spiked human plasma using multivariate model update chemometric methods.

Combination of bendamustine (BEN), gemcitabine (GEM), and vinorelbine (VIB), (BEGEV) regimen, has been proved to be a tolerable, safe and effective regimen in relapsed/refractory classical hodgkin lymphoma (R/R cHL). Two chemometric models named principal component regression (PCR) and partial least squares (PLS) were established for determination and quantification of BEN, GEM and VIB simultaneously in the ranges of 5-25 µg/mL for each of BEN and VIB, while in the range of 10 -30 µg/mL for GEM in pure and spiked plasma using their UV absorbance. The updated methods have been proven their ability to predict the concentrations of the studied drugs and validated according to FDA guidelines showing good results. There was no significant difference between the developed methods and the reported LC-MS/MS method upon statistical comparison was applied. Furthermore, the updated chemometric methods have advantages of being sensitive, accurate and cost effective for estimation of BEN, GEM and VIB and monitoring their concentration.

Ecofriendly LC-MS/MS and TLC-densitometric methods for simultaneous quantitative assay and monitoring of BEGEV regimen, in vivo pharmacokinetic study application.

To date no analytical method has been developed for the determination of the BEGEV regimen and no study has investigated the kinetic interaction between the drugs, to give us priorities for further clinical study, so two rapid, accurate, sensitive and ecofriendly chromatographic methods were developed for the simultaneous determination of bendamustine (BEN), gemcitabine (GEM) and vinorelbine (VIB) using sildenafil (SIL) as an internal standard (IS) for the purpose of an in vivo pharmacokinetics study in rats. Firstly, the LC-MS/MS method was performed using a mixture of methanol and a 0.1% aqueous solution of formic acid as the mobile phase on a ZORBAX Eclipse Plus C18 (4.6 mm × 150 mm, 5 µm) column as the stationary phase. BEN, GEM and VIB were ionized by positive ions and detected in the multi-reaction monitoring (MRM) mode using precursor → products of m/z 358.20 → 228.25 for BEN, m/z 264.05 → 112.15 for GEM, m/z 779.55 → 122.20 for VIB and m/z 475.00 → 58.35 for SIL. Secondly, TLC-densitometry was applied on TLC silica gel plates using methanol : ethyl acetate (8 : 2, v/v) as the developing system when the separated peaks were scanned at 280 nm. FDA guidelines were followed for validation of the proposed methods, which presented acceptable ranges; then they were applied for an in vivo study in rats with a quantitative determination of each drug after single or combined administration for an investigation of any suspected drug-drug interaction, and all pharmacokinetic parameters were calculated for therapeutic drug monitoring of those drugs. Green analytical chemistry principles were considered during all the procedural steps to ensure the greenness and the safety of the methods, which were evaluated using four assessment tools, eco-scale assessment, the national environmental method index (NEMI), the green analytical procedure index (GAPI) and the analytical greenness metric approach (AGREE), and the results were satisfactory.

Chromatographic analysis of bromhexine and oxytetracycline residues in milk as a drug analysis medium with greenness profile appraisal.

Tetracyclines are frequently employed in animal husbandry. Bromhexine is a mucolytic drug that improves the efficacy of tetracyclines. It has been reported that residues of tetracyclines in milk may have negative effects on humans. Two versatile and accurate methods were developed for concurrent analysis of oxytetracycline (OTC) and bromhexine (BR) residues in spiked milk samples. Sample preparation was carefully considered for extraction and cleanup using the ecofriendly chemicals acetic acid, 0.1 N EDTA and ethanol or methanol. The first method was a TLC-densitometric method in which TLC plates previously treated with 10% EDTA (pH 9 with 40% sodium hydroxide) were used as a stationary phase. A solvent mixture of methanol : methylene chloride : 2% aqueous acetic acid (8 : 2 : 0.5, by volume) was the developing system, and detection was carried out at 254 nm. Metformin was used as the internal standard, and linearity was achieved in the ranges of 0.2-10 and 0.04-2 µg per band for OTC and BR, respectively. The second method was a RP-HPLC method; separation was performed on a C18 column using an isocratic mixture of ethanol : 7.5% aqueous acetic acid (70 : 30, v/v). Separation was achieved within 10 minutes, and linearity was proven in the ranges of 0.05-50 and 0.05-30 µg mL-1 for OTC and BR, respectively. Diclofenac sodium was used as an internal standard. The proposed methods were validated in accordance with the FDA Center for Veterinary Medicine guidelines. Moreover, the performance and health and environmental impacts of the methods were evaluated using several greenness metrics, namely, the National Environmental Methods Index (NEMI), modified NEMI, Green Analytical Procedure Index (GAPI), Analytical Eco-Scale and Analytical GREEnness (AGREE) metric approaches. All the obtained results proved the validity of the developed methods concerning its performance and ecological effects. The methods can be used to investigate the presence of OTC residues in various marketed milk samples to maintain public health.

Five spectrophotometric methods for simultaneous determination of Amlodipine besylate and celecoxib in presence of its toxic impurity.

Five simple, selective and accurate spectrophotometric methods have been applied and developed for first time for simultaneous determination of amlodipine besylate (AML) and celecoxib (CEL) in presence of one harmful impurity, 4-methylacetophenone (MAP), in their ternary mixture without prior separation. Those spectrophotometric methods were developed and called: dual wave length in ratio spectra (DWRS), successive ratio-derivative spectra (SDR), modified absorption factor method (MAFM), modified amplitude center method (MACM) and first derivative -zero crossing coupled with amplitude factor method (FDAF). These methods include various steps using zero /or ratio /or derivative spectra and some mathematical techniques. Linear calibration curves were constructed over the concentration range of 2-100, 10-200 and 0.5-20 µg/mL for AML, CEL and MAP, respectively. High sensitivity with low LOD values 0.583, 3.118 and 0.147 for AML, CEL and MAP, respectively were obtained. Moreover, validation of the proposed methods was achieved according to ICH guidelines and satisfactory results were obtained indicating that the developed methods can be used for quality control analysis of AML and CEL concerning its impurity. No significant difference was observed when the obtained results of the developed methods were statistically compared with the reported HPLC method.