Potentiometric detection of apomorphine in human plasma using a 3D printed sensor.

Apomorphine is a dopamine agonist that is used for the management of Parkinson's disease and has been proven to effectively decrease the off-time duration, where the symptoms recur, in Parkinson's disease patients. This paper describes the design and fabrication of the first potentiometric sensor for the determination of apomorphine in bulk and human plasma samples. The fabrication protocol involves stereolithographic 3D printing, which is a unique tool for the rapid fabrication of low-cost sensors.

Comparative HPTLC study for simultaneous determination of ivabradine and metoprolol using UV and fluorescence detectors.

New, simple, accurate, sensitive and validated high performance thin layer chromatographic (HPTLC) method coupled with UV absorbance mode and fluorescence (FL) detectors which were used for simultaneous determination of ivabradine (IVA) and metoprolol (MET) in their bulk and pharmaceutical dosage form using TLC silica 60 F plates and non-fluorescent TLC silica gel 60 plates. The developing system was chloroform: methanol: formic acid: ammonia (8.5:1.

The potential off-target neuroprotective effect of sister gliflozins suggests their repurposing despite not crossing the blood-brain barrier: From bioanalytical assay in rats into theory genesis.

Gliflozins are successfully marketed antidiabetic agents with a reported neuroprotective effect, and this study tests their blood-brain barrier crossing ability. Henceforward, a computational hypothesis interpreting their effects was reasonable after failure to cross into the brain. A chromatographic bioassay for canagliflozin, dapagliflozin, and empagliflozin was developed, validated, and applied to the rat's and rat's plasma and brain.

Univariate and Multivariate Determination of Dapagliflozin and Saxagliptin in Bulk and Dosage Form.

Background: Dapagliflozin is a sodium glucose cotransporter-II inhibitor while saxagliptin is a dipeptidyl peptidase-4 inhibitor. Both are used to manage type 2 diabetes mellitus.

Objective: The aim of this work is to develop four simple, accurate, and precise UV-spectrophotometric methods, three univariate and one multivariate, for the estimation of dapagliflozin and saxagliptin in their pure and marketed dosage forms.

Omarigliptin attenuates rotenone-induced Parkinson's disease in rats: Possible role of oxidative stress, endoplasmic reticulum stress and immune modulation.

The current study aimed to explore the potential neuroprotective effect of omarigliptin (OG), an antidiabetic drug that crosses the blood-brain barrier (BBB), in a Parkinson's disease (PD) rotenone-based rat-model. Results showed that OG attenuated motor impairment, histological aberrations, α-synuclein accumulation, and rescued the dopaminergic neurons in rotenone-administered rats. Furthermore, OG halted rotenone-induced oxidative stress; as shown by reduced lipid peroxidation, decline in the oxidative stress sensor (nuclear factor erythroid 2-related factor 2) and its downstream heme oxygenase-1.

Investigation of Pharmacokinetic Parameters of Trelagliptin in Egyptian Volunteers Using Sensitive LC-MS/MS: A Comparative Study with a Japanese Population.

Trelagliptin (TLN) is a novel once-weekly antidiabetic drug that enhanced the patient compliance in type 2 diabetes. TLN analysis and bioanalysis literature review showed many methods for TLN assay either in dosage form or as biological fluids (pharmacokinetic parameters), but all those methods did not consider the full details dealing with biological assay of TLN. Studies that included information about pharmacokinetic parameters did not mention the used analytical procedures for those determinations and parameters.

Repurposing of Omarigliptin as a Neuroprotective Agent Based on Docking with A Adenosine and AChE Receptors, Brain GLP-1 Response and Its Brain/Plasma Concentration Ratio after 28 Days Multiple Doses in Rats Using LC-MS/MS.

The authors in the current work suggested the potential repurposing of omarigliptin (OMR) for neurodegenerative diseases based on three new findings that support the preliminary finding of crossing BBB after a single dose study in the literature. The first finding is the positive results of the docking study with the crystal structures of A adenosine (A2AAR) and acetylcholine esterase (AChE) receptors. A2AAR is a member of non-dopaminergic GPCR superfamily receptor proteins and has essential role in regulation of glutamate and dopamine release in Parkinson's disease while AChE plays a major role in Alzheimer's disease as the primary enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine into choline and acetate.

Enhanced Extraction Technique of Omarigliptin from Human Plasma-Applied to Biological Samples from Healthy Human Volunteers.

Enhancing drug extraction from human plasma is a challenging approach that critically affects pharmacokinetic and any further clinical studies based on the drug C and C values. It also has a serious impact on the sensitivity and the lower limit of quantification (LLOQ) value of the bio-analytical methods. An advanced liquid chromatography tandem mass spectrometry (LC-MS/MS) bio-analytical method of omarigliptin (25-1000 nM) was established in human plasma using one-step liquid-liquid extraction.

Repositioning of Omarigliptin as a once-weekly intranasal Anti-parkinsonian Agent.

Drug repositioning is a revolution breakthrough of drug discovery that presents outstanding privilege with already safer agents by scanning the existing candidates as therapeutic switching or repurposing for marketed drugs. Sitagliptin, vildagliptin, saxagliptin & linagliptin showed antioxidant and neurorestorative effects in previous studies linked to DPP-4 inhibition. Literature showed that gliptins did not cross the blood brain barrier (BBB) while omarigliptin was the first gliptin that crossed it successfully in the present work.

Different Spectrophotometric Methods for Simultaneous Determination of Trelagliptin and Its Acid Degradation Product.

New spectrophotometric and chemometric methods were carried out for the simultaneous assay of trelagliptin (TRG) and its acid degradation product (TAD) and applied successfully as a stability indicating assay to recently approved Zafatek® tablets. TAD was monitored using TLC to ensure complete degradation. Furthermore, HPLC was used to confirm dealing with one major acid degradation product.

Factorial design optimization of micelle enhanced synchronous spectrofluorimetric assay of Omarigliptin: Applied to content uniformity testing and in vitro drug release.

A micelle enhanced spectrofluorimetric method was developed for determination of Omarigliptin (OMG) based on its native fluorescence behavior. The interaction of OMG with surfactants and macromolecules was studied. In aqueous solution, the relative fluorescence intensity (RFI) of OMG was enhanced by 24% in the presence of Tween 80 at pH 3.

Comparative Liquid Chromatographic Study for Concurrent Determination of Canagliflozin and Metformin in Combined Tablets.

New HPLC-UV method (method A), for simultaneous determination of metformin (MET) and canagliflozin (CANA), was developed and compared to another novel UPLC-UV method (method B) in their tablet combination. Concerning method A, isocratic separation was done by C18 column (100 mm × 2.1 mm, 3 m) using methanol and 0.

Suitability of various chromatographic and spectroscopic techniques for analysis and kinetic degradation study of trelagliptin.

Multifaceted comparative analytical methods for trelagliptin (TRL) were investigated, applied to ZAFATEK tablets and HPLC-UV was selected for a degradation kinetic study. UPLC-MS/MS (Method I), UPLC-UV (Method II), HPLC-UV (Method III), UHPLC-UV (Method IV) and direct UV (Method V) methods were developed. Methods (I-V) showed satisfactory results using TRL concentration ranges of 50-800 ng/mL, 2.

Different applications of isosbestic points, normalized spectra and dual wavelength as powerful tools for resolution of multicomponent mixtures with severely overlapping spectra.

Background: Analysis of complex mixture containing three or more components represented a challenge for analysts. New smart spectrophotometric methods have been recently evolved with no limitation. A study of different novel and smart spectrophotometric techniques for resolution of severely overlapping spectra were presented in this work utilizing isosbestic points present in different absorption spectra, normalized spectra as a divisor and dual wavelengths.

Comparative study between different simple methods manipulating ratio spectra for the analysis of alogliptin and metformin co-formulated with highly different concentrations.

Different simple spectrophotometric methods were developed for simultaneous determination of alogliptin and metformin manipulating their ratio spectra with successful application on recently approved combination, Kazano® tablets. Spiking was implemented to detect alogliptin in spite of its low contribution in the pharmaceutical formulation as low quantity in comparison to metformin. Linearity was acceptable over the concentration range of 2.

Pharmacokinetic Evaluation of Empagliflozin in Healthy Egyptian Volunteers Using LC-MS/MS and Comparison with Other Ethnic Populations.

The present study considered the pharmacokinetic evaluation of empagliflozin after administration to Egyptian volunteers, and the results were compared with other ethnic populations. The FDA recognizes that standard methods of defining racial subgroups are necessary to compare results across pharmacokinetic studies and to assess potential subgroup differences. The design of the study was as an open labeled, randomized, one treatment, one period, single dose pharmacokinetic study.

LC-MS/MS Determination of Empagliflozin and Metformin.

A new LC-MS/MS method was developed for determination of empagliflozin and metformin. Bridged Ethylene Hybrid C18 column (50 mm × 2.1 mm, 1.

A Validated HPLC Method for Simultaneous Determination of Perindopril Arginine, Amlodipine, and Indapamide: Application in Bulk and in Different Pharmaceutical Dosage Forms.

A simple, accurate, and precise LC method with a reversed stationary phase was developed and validated for the determination of perindopril (PER) arginine, amlodipine (AML), and indapamide (IND) alone and in binary mixtures (PER arginine is found in two dosage forms, i.e., with either AML or IND).

Novel Pure Component Contribution Algorithm (PCCA) and UHPLC Methods for Separation and Quantification of Amlodipine, Valsartan, and Hydrochlorothiazide in Ternary Mixture.

Two accurate and sensitive methods were developed and validated for the simultaneous determination of amlodipine (AML), valsartan (VAL), and hydrochlorothiazide (HCT) in their ternary mixture. The first method is a novel simple algorithm capable of extracting the contribution of each component from a mixture signal in which the components are partially or completely overlapped. It is based on the use of a coded function that eliminates the signal of interfering components using mean centering as a processing tool.

Evaluation of the efficiency of continuous wavelet transform as processing and preprocessing algorithm for resolution of overlapped signals in univariate and multivariate regression analyses; an application to ternary and quaternary mixtures.

Wavelets have been adapted for a vast number of signal-processing applications due to the amount of information that can be extracted from a signal. In this work, a comparative study on the efficiency of continuous wavelet transform (CWT) as a signal processing tool in univariate regression and a pre-processing tool in multivariate analysis using partial least square (CWT-PLS) was conducted. These were applied to complex spectral signals of ternary and quaternary mixtures.

Validated HPLC and Ultra-HPLC Methods for Determination of Dronedarone and Amiodarone Application for Counterfeit Drug Analysis.

Two simple, accurate, and precise chromatographic methods have been developed and validated for the determination of dronedarone (DRO) HCl and amiodarone (AMI) HCl either alone or in binary mixtures due to the possibility of using AMI as a counterfeit of DRO because of its lower price. First, an RP-HPLC method is described for the simultaneous determination of DRO and AMI. Chromatographic separation was achieved on a BDS Hypersil C18 column (150×4.

Validated spectrophotometric methods for simultaneous determination of Omeprazole, Tinidazole and Doxycycline in their ternary mixture.

A comparative study of smart spectrophotometric techniques for the simultaneous determination of Omeprazole (OMP), Tinidazole (TIN) and Doxycycline (DOX) without prior separation steps is developed. These techniques consist of several consecutive steps utilizing zero/or ratio/or derivative spectra. The proposed techniques adopt nine simple different methods, namely direct spectrophotometry, dual wavelength, first derivative-zero crossing, amplitude factor, spectrum subtraction, ratio subtraction, derivative ratio-zero crossing, constant center, and successive derivative ratio method.

A comparative study of smart spectrophotometric methods for simultaneous determination of sitagliptin phosphate and metformin hydrochloride in their binary mixture.

Simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the oral antidiabetic drugs; sitagliptin phosphate (STG) and metformin hydrochloride (MET) in combined pharmaceutical formulations. Three methods were manipulating ratio spectra namely; ratio difference (RD), ratio subtraction (RS) and a novel approach of induced amplitude modulation (IAM) methods. The first two methods were used for determination of STG, while MET was directly determined by measuring its absorbance at λmax 232 nm.

Novel spectrophotometric methods for simultaneous determination of Amlodipine, Valsartan and Hydrochlorothiazide in their ternary mixture.

This work represents a comparative study of two smart spectrophotometric techniques namely; successive resolution and progressive resolution for the simultaneous determination of ternary mixtures of Amlodipine (AML), Hydrochlorothiazide (HCT) and Valsartan (VAL) without prior separation steps. These techniques consist of several consecutive steps utilizing zero and/or ratio and/or derivative spectra. By applying successive spectrum subtraction coupled with constant multiplication method, the proposed drugs were obtained in their zero order absorption spectra and determined at their maxima 237.

Validated stability-indicating HPLC method for the determination of mesna in presence of its degradation products.

A rapid and simple stability-indicating liquid chromatographic method was developed and validated for analysis of mesna in the presence of its degradation products in drug substance and drug products in a run time not >5 min. The separation was achieved on a RP amide C16 column at room temperature using methanol-phosphate buffer (10:90, v/v, pH 3.0) as mobile phase at a flow rate of 1 mL min(-1) and UV detection at 210 nm.