Green HPLC-DAD and HPTLC Methods for Quantitative Determination of Binary Mixture of Pregabalin and Amitriptyline Used for Neuropathic Pain Management.

First analytical methods were herein developed for determination of pregabalin (PGB) and amitriptyline (AMT) as an active binary mixture used for management of neuropathic pain whether in pure forms or in human biological fluids (plasma/urine). First method is green high-performance liquid chromatography-diode array detector (HPLC-DAD) after derivatization of PGB with ninhydrin (NIN) on a reversed-phase C18 column using a mobile phase consisting of ethanol:water (97:3%, v/v) pumped isocratically at 0.8 mL/min; AMT were scanned at 215 nm, whereas PGB-NIN was scanned at 580 nm.

Development and validation of a stability indicating RP-HPLC-DAD method for the determination of bromazepam.

A reliable, selective and sensitive stability-indicating RP-HPLC assay was established for the quantitation of bromazepam (BMZ) and one of the degradant and stated potential impurities; 2-(2-amino-5-bromobenzoyl) pyridine (ABP). The assay was accomplished on a C18 column (250 mm × 4.6 mm i.

Ecologically evaluated and FDA-validated HPTLC method for assay of pregabalin and tramadol in human biological fluids.

The introduced research presents a novel in vivo quantitative method for assay of mixtures of pregabalin and tramadol as a common combinations approved for treatment of neuropathic pain. Green analytical chemistry is a recently emerging science concerned with control of the use of chemicals harmful to the environment in various analytical methods. Consequently, a green high-performance thin layer chromatography (HPTLC) method was achieved for determination of the mixture in human plasma and urine satisfying both analytical and environmental standards.

US FDA-validated green GC-MS method for analysis of gabapentin, tramadol and/or amitriptyline mixtures in biological fluids.

Mixtures of gabapentin, tramadol and/or amitriptyline are usually recommended for treatment of neuropathic pain. A novel GC-MS/MS method was developed to assess the studied mixture whether in pure forms or human biological fluids (plasma/urine). The chromatographic detection was performed using MS detector applying the selected ion-monitoring mode.

Stability indicating spectrophotometric methods for quantitative determination of bromazepam and its degradation product.

Four simple, sensitive and selective stability indicating spectrophotometric methods are presented for quantitative determination of the benzodiazepine drug; bromazepam (BMZ) and one of its reported potential impurities and degradation product; 2-(2-amino-5-bromobenzoyl) pyridine (ABP) in methanol. Method A, is isoabsorptive point coupled with D method, where good linearity was obtained by measuring the absorbance of BMZ at 264 nm (A) in the concentration range of 2-25 μg mL, and the absorbance of ABP at its λ 396 nm in concentration range of 0.5-24 μg mL.

Stability-Indicating HPLC and HPTLC Methods for Determination of Agomelatine and its Degradation Products.

Two accurate, sensitive and highly selective stability-indicating methods are developed and validated for simultaneous determination of Agomelatine (AGM) and its forced degradation products (Deg I and II). The first method is High-Performance Liquid Chromatography for separation and quantitation of AGM, Deg I and II on a C18 column (250 mm × 4.6 mm, 5 μm p.

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

Two accurate, sensitive, and selective stability-indicating methods are developed and validated for simultaneous quantitative determination of agomelatine (AGM) and its forced degradation products (Deg I and Deg II), whether in pure forms or in pharmaceutical formulations. Partial least-squares regression (PLSR) and spectral residual augmented classical least-squares (SRACLS) are two chemometric models that are being subjected to a comparative study through handling UV spectral data in range (215-350 nm). For proper analysis, a three-factor, four-level experimental design was established, resulting in a training set consisting of 16 mixtures containing different ratios of interfering species.

HPTLC Method for Quantitative Determination of Zopiclone and Its Impurity.

This study was designed to establish, optimize and validate a sensitive, selective and accurate high-performance thin layer chromatographic (HPTLC) method for determination of zopiclone (ZPC) and its main impurity, 2-amino-5-chloropyridine, one of its degradation products, in raw material and pharmaceutical formulation. The proposed method was applied for analysis of ZPC and its impurity over the concentration range of 0.3-1.

Quantitative determination of zopiclone and its impurity by four different spectrophotometric methods.

Four simple, sensitive and selective spectrophotometric methods are presented for determination of Zopiclone (ZPC) and its impurity, one of its degradation products, namely; 2-amino-5-chloropyridine (ACP). Method A is a dual wavelength spectrophotometry; where two wavelengths (252 and 301 nm for ZPC, and 238 and 261 nm for ACP) were selected for each component in such a way that difference in absorbance is zero for the second one. Method B is isoabsorptive ratio method by combining the isoabsorptive point (259.