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. Second method is High-performance thin-layer chromatography (HPTLC), where PGB and AMT were separated on silica gel HPTLC F254 plates, using ethanol:ethyl acetate:acetone:ammonia solution (8:2:1:0.05, by volume) as a developing system. AMT peaks were scanned at 220 nm, whereas PGB peaks were visualized by spraying 3% (w/v) ethanolic NIN solution and scanning at 550 nm. Linear calibration curves were obtained for human plasma and urine spiked with PGB and AMT over the ranges of 5-100 µg/mL and 0.2-2.5 µg/band for PGB, and 1-100 µg/mL and 0.1-2.0 µg/band for AMT for HPLC-DAD and HPTLC methods, respectively. The suggested methods were validated according to Food and Drug Administration guidelines for bioanalytical methods validation and they can be applied for routine therapeutic drug monitoring for the concerned drugs.

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. The separation was achieved on HPTLC sheets using a separating mixture of ethanol-ethyl acetate-acetone-ammonia solution (8:2:1:0.05, by volume) as a mobile phase. The sheets were dried in air then scanned at two wavelengths. For tramadol, 220 nm was chosen; however, pregabalin is an unconjugated drug, so its determination was a challenge. Hence for pregabalin, the plates were sprayed with ethanolic solution of ninhydrin (3%, w/v), to obtain a conjugated complex, which could be assessed at 550 nm. Furthermore, the developed method fulfilled the US Food and Drug Administration validation guidelines, and proved to be useful in therapeutic drug monitoring of this combination. The Eco-scale assessment protocol was implemented to determine the greenness profile of the applied method.

Antioxidant and anti-inflammatory properties of alpha-lipoic acid protect against valproic acid-induced liver injury.

Valproic acid (VPA) is one of the most used antiepileptic drugs despite of its many adverse effects such as anemia, leucopenia, thrombocytopenia, and liver toxicity. The hepatoprotective effect of alpha-lipoic acid (ALA) was confirmed. The aim of this study was to detect the protective effect of ALA against the adverse effects of VPA. To study this, 30 white albino Wistar male rats were divided into four groups. Group I was the control group; Group II included rats that received ALA (100 mg·kg-1·day-1) orally for 14 days; Group III and Group IV included rats that received VPA (500 mg·kg-1·day-1) for 15 days intraperitoneally, but Group IV rats received ALA (100 mg·kg-1·day-1) orally for 14 days prior to VPA. Blood samples were collected and livers were excised from rats for colorimetric analysis and quantitative real-time PCR. The rats that received VPA showed leucopenia, thrombocytopenia, a significant decrease of superoxide dismutase, glutathione, nuclear factor erythroid 2-related factor 2, and sirtuin 1, besides a significant increase of malondialdehyde and tumor necrosis factor α. Prior treatment with ALA prevented all these results; ALA protected against VPA-induced liver damage and hematological disturbance via antioxidant and anti-inflammatory properties.

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

Background: Mixtures of gabapentin, tramadol and/or amitriptyline are usually recommended for treatment of neuropathic pain. Materials & methods/results: 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. An (Agilent, CA, USA) GC-MS with triple axis single quadrupole detector unit was used for the analysis equipped with HP-5MS (5% phenyl methyl siloxane) column. Helium was the carrier gas and positive electron impact ionization mode was applied. Conclusion: The developed method was able to assess the mixture components simultaneously within six minutes. Validation of the method was assured according to US FDA guidelines and Eco-Scale assessment.

Identification of victims from mass grave discovery near Benghazi, Libya.

BACKGROUND: A mass grave is any site that containing two or more associated corpses, at random or on purpose placed, of people who have died as a result of extra-judicial or random executions, not including those people who have died from armed confrontations or known major catastrophes. CASE PRESENTATION: The purpose of this paper is to explain how to reconstruct a biological profile of decomposed or skeletonized bodies and clarify the efforts done by the Libyan scientist after 2011 revolution and to set a reference for other researcher. The alleged location of the grave, as well as the alleged number and identities of the persons buried in the grave were obtained exclusively from witnesses' and relatives' testimonies. CONCLUSION: As the testimonies said, the grave was located at the alleged location and seven skeletons were exhumed. Also, the osteological and DNA study made investigators to identify the exhumed skeletons. And the dental analysis support the identification of a seven man alleged to have been buried in the grave, 7 victims were discovered.

Stability indicating spectrophotometric methods for quantitative determination of carbamazepine and its degradation product, iminostilbene, in pure form and pharmaceutical formulations.

A stressed study on the stability and degradation behavior under ICH forced degradation conditions of most widely used antiepileptic drug; carbamazepine (CMZ) is presented in this work. The research also includes studying spectrophotometric nature of CMZ and assaying it with mostly used spectrophotometric techniques. Six simple and sensitive spectrophotometric methods are introduced as stability indicating methods for quantitative determination of CMZ and its degradation product, one of its reported potential impurities; iminostilbene (IMS). Dual wavelength is method I where two wavelengths (215 and 270 nm for CMZ and 258 and 307 nm for IMS) were chosen for each component while absorbance difference is zero for the second one. Method II is isoabsorptive point method where the absorbance of CMZ at A225 nm was measured in the range of 0.5-20 µg mL-1. Method III is second derivative method which allows simultaneous determination of CMZ at 247 nm and IMS at 273 nm without any interference. Method IV based on measuring the peak amplitude of first derivative of ratio spectra (1DD) at 280.5 and 253 nm for determination of CMZ and IMS, respectively. Method V is mean centering of the ratio spectra with good linearity for CMZ and IMS over 200-330 nm. Ratio difference method is method VI where good linearity was achieved for determination of CMZ and IMS by measuring differences in the amplitude of ratio spectra at 285, 258 nm and 258, 285 nm, respectively. The proposed methods show successful application in CMZ's pharmaceutical formulations.