Two Chromatographic Methods for the Determination of Some Antimigraine Drugs

Two stability indicating chromatographic methods were proposed for the determination of almotriptan, eletriptan, and rizatriptan, in presence of their acid degradation products. The first method is a quantitative densitometric thin layer chromatography. The developing systems were; acetonitrile: methanol: dichloromethane: ammonia (10:6:3:1 v/v), ethyl acetate: methanol: ammonia (15:4:1 v/v), and methanol: acetonitrile: ammonia (9:4:1 v/v) for almotriptan, eletriptan and rizatriptan respectively. The TLC plates were scanned at 235 nm. Linear relationships were obtained over concentration ranges (5–50 μg/spot) for almotriptan and rizatriptan, and (5–60 μg/spot) for eletriptan. The second method based on the separation and determination of the studied drugs, using RP-HPLC technique. The separation was achieved on C18 Hypersil column, elution was carried out using phosphate buffer pH 3: methanol: acetonitrile (2: 1:1 v/v) at flow rate 2 mL/min and UV detection at 235 nm. Linear relationships were obtained over concentration ranges (10–200 μg/mL) for almotriptan and eletriptan, and (10–180 μg/mL) for rizatriptan. The chromatographic methods were successfully applied for the determination of each of the studied drugs in pure form, tablet form, and in laboratory prepared mixtures with their acid degradation products

SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF DICLOFENAC SODIUM, PARACETAMOL, AND CHLORZOXAZONE IN TERNARY MIXTURE USING CHEMOMETRIC AND ARTIFICIAL NEURAL NETWORKS TECHNIQUES

  Objective: The aim of this study is to develop and validate simple, accurate, and precise spectrophotometric methods for the simultaneous determination of diclofenac sodium (DIC), paracetamol (PAR), and chlorzoxazone (CHZ) in ternary mixture using chemometric and artificial neural networks (ANN) techniques.Methods: Three chemometric techniques include classical least squares (CLS), principal component regression (PCR), and partial least squares (PLS) in addition to cascade-forward backpropagation ANN (CFBP-ANN) were prepared using the synthetic mixtures containing the three drugs in methanol. In CLS, PCR, and PLS, the absorbances of the synthetic mixtures in the range 267-295 nm with the intervals Δλ=0.2 nm in their zero-order spectra were selected. Then, calibration or regression was obtained using the absorbance data matrix and concentration data matrix for the prediction of the unknown concentrations of DIC, PAR, and CHZ in their mixtures. In CFBP-ANN, two layers, sigmoid layer with 10 neurons and linear layer were found appropriate for the simultaneous determination of the three drugs in their ternary mixture.Results: The four proposed methods were successfully applied to the analysis of the three drugs in laboratory prepared mixtures and tablets with good percentage recoveries in the range of 98-102%. Relative standard deviation for the precision study was found <1%.Conclusion: The four proposed methods showed simplicity, accuracy, precision, and rapidity making them suitable for quality control and routine analysis of the cited drugs in ternary mixtures and pharmaceutical formulation containing them.Â

Spectrophotometric and Spectrofluorimetric Studies on Azilsartan Medoxomil and Chlorthalidone to Be Utilized in Their Determination in Pharmaceuticals

The recently approved angiotensin II receptor blocker, azilsartan medoxomil (AZL), was determined spectrophotometrically and spectrofluorimetrically in its combination with chlorthalidone (CLT) in their combined dosage form. The UV-spectrophotometric technique depends on simultaneous measurement of the first derivative spectra for AZL and CLT at 286 and 257 nm, respectively, in methanol. The spectrofluorimetric technique depends on measurement of the fourth derivative of the synchronous spectra intensities of AZL in presence of CLT at 298 nm in methanol. The effects of different solvents on spectrophotometric and spectrofluorimetric responses were studied. For, the spectrofluorimetric study, the effect of pH and micelle-assisted fluorescence enhancement were also studied. Linearity, accuracy, and precision were found to be satisfactory over the concentration ranges of 8–50 μg mL-1 and 2–20 μg mL-1 for AZL and CLT, respectively, in the spectrophotometric method as well as 0.01–0.08 μg mL-1 for AZL in the spectrofluorimetric method. The methods were successfully applied for the determination of the studied drugs in their co-formulated tablets. The developed methods are inexpensive and simple for the quality control and routine analysis of the cited drugs in bulk and in pharmaceuticals

UPLC–MS-MS Method for the Determination of Vilazodone in Human Plasma: Application to a Pharmacokinetic Study

A sensitive, rapid and simple liquid chromatographic-electrospray ionization tandem mass spectrometric (LC-ESI-MS-MS) method was developed for the quantitative determination of vilazodone in human plasma and for the study of the pharmacokinetic behavior of vilazodone in healthy Egyptian volunteers. With escitalopram as internal standard (IS), liquid-liquid extraction was used for the purification and preconcentration of analytes from human plasma matrix using diethyl ether. The separation was performed on an Acquity UPLC BEH shield RP C18 column (1.7 µm, 2.1 × 150 mm). Isocratic elution was applied using methanol-0.2% formic acid (90:10, v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring mode via an electrospray ionization source at m/z 442.21 → 155.23 for vilazodone and m/z 325.14 → 109.2 for escitalopram. Linear calibration curves were obtained over the range of 1-200 ng/mL with the lower limit of quantification at 1 ng/mL. The intra- and inter-day precision showed relative standard deviation ≤3.3%. The total run time was 1.5 min. This method was successfully applied for clinical pharmacokinetic investigation, and a preliminary metabolic study was also carried out

Simultaneous Determination of Metformin, Vildagliptin and 3-amino-1-adamantanol in Human Plasma: Application to Pharmacokinetic Studies

Metformin (MET) and vildagliptin (VLD) are coformulated in tablets for the management of diabetes mellitus. The aim of this study is the development of a new fast ultraperformance liquid chromatography method with tandem mass detection (UPLC–MS/MS) for their simultaneous determination with 3-amino-1-adamantanol (starting compound for vildagliptin synthesis; VLI) in human plasma. Separation of MET, VLD, and VLI was performed on a 5 cm UPLC-C18 column using a mobile phase of 0.5% acetic acid in methanol and 0.02 M aqueous ammonium acetate (10:90, v/v). The injection volume was 10 µL and electrospray positive ionization was applied. Extraction from human plasma was carried out by acid precipitation of plasma proteins using pregabalin as an internal standard. The assay was validated according to ICH guidelines. The developed method is valid, fast, and simple and was successfully applied in pharmacokinetic studies in human volunteers

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 × 4.6 mm, 5 μm). Isocratic elution based on potassium dihydrogen phosphate buffer with 0.1% triethylamine pH 6–methanol (10 + 90, v/v) at a flow rate of 2 mL/min with UV detection at 254 nm was performed. The second method is RP ultra-HPLC in which the chromatographic separation was achieved on an AcclaimTM RSLC 120 C18 column (100 × 2.1 mm, 2.2 μm) using isocratic elution with potassium dihydrogen phosphate buffer with 0.1% triethylamine pH 6–methanol (5 + 95, v/v) at a flow rate of 1 mL/min with UV detection at 254 nm. Linearity, accuracy, and precision of the two methods were found to be acceptable over the concentration ranges of 5–80 μg/mL for both DRO and AMI. The results were statistically compared using one-way analysis of variance. The optimized methods were validated and proved to be specific, robust, precise, and accurate for the QC of the drugs in their pharmaceutical preparations

Simultaneous determination of ciprofloxacin hydrochloride and metronidazole in spiked human plasma by ultra performance liquid chromatography-tandem mass spectroscopy

Ciprofloxacin HCl (CIP) and Metronidazole (MET) are antibacterial drugs used in combination for treatment of mixed aerobic/anaerobic infections. An UPLC-MS/MS method was developed for the simultaneous estimation of CIP and MET in spiked human plasma using sildenafil citrate as an internal standard (IS). Protein precipitation was used for analyte extraction. The chromatographic separation was completed within 6 min using a mobile phase of 0.1% formic acid in water and acetonitrile (70: 30, v/v), Zorbax C18, 100 x 4.6 mm, 3.5 µm analytical column, at a flow rate of 0.5 mL min -1 . Multiple reaction monitoring (MRM) transitions were measured in the positive ion mode. Validation of the method showed standard curves to be linear in the range of 10-4000 ng mL -1 for CIP and 30-12000 ng mL -1 for MET with mean correlation coefficient exceeding 0.999. In human plasma, CIP and MET were stable for at least 36 days at –70 ± 5 °C, 6 hours at ambient temperature and after three freeze thaw cycles. After extraction from plasma, the samples were stable in auto sampler at 22 °C for 6 hours. The method was simple, specific, sensitive, precise, accurate and suitable for bioequivalence and pharmacokinetic studies

Stability-Indicating RP-HPLC Methods for the Determination of Fluorometholone in Its Mixtures with Sodium Cromoglycate and Tetrahydrozoline Hydrochloride.

Two stability-indicating reversed-phase liquid chromatographic methods were developed and validated for the determination of fluorometholone (FLU) in its mixtures with sodium cromoglycate (SCG) and tetrahydrozoline hydrochloride (THZ). The first HPLC method (Method 1) was based on isocratic elution of FLU and SCG along with their alkaline degradation products on a reversed phase C18 column (250 × 4.6 mm id)-ACE Generix 5, using a mobile phase consisting of methanol-water (70 : 30, v/v), pH adjusted to 2.5 using orthophosphoric acid at a flow rate of 1.2 mL min(-1) Quantitation was achieved with UV detection at 240 nm. The second HPLC method (Method 2) was based on isocratic elution of FLU, its alkaline degradation product and THZ on a reversed phase C8 column (250 × 4.6 mm)-ACE Generix 5, using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen orthophosphate (40 : 60, v/v) at a flow rate of 2 mL min(-1) Quantitation was achieved by applying dual-wavelength detection, where FLU and its alkaline degradation product were detected at 240 nm and THZ was detected at 215 nm at ambient temperatures. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5-50 and 10-500 μg mL(-1) for FLU and SCG (Method 1) and over the concentration range of 5-80 and 5-60 μg mL(-1) for FLU and THZ (Method 2), respectively. Besides, the FLU alkaline degradation product was verified using IR, NMR and LC-MS spectroscopy. The two proposed methods could be successfully applied for the routine analysis of the studied drugs either in their pure bulk powders or in their pharmaceutical preparations without any preliminary separation step

Forced degradation of mometasone furoate and development of two RP-HPLC methods for its determination with formoterol fumarate or salicylic acid

Two simple, selective and precise stability-indicating reversed-phase liquid chromatographic methods were developed and validated for the determination of mometasone furoate in two binary mixtures, with formoterol fumarate (Mixture 1) and salicylic acid (Mixture 2). Also, a forced degradation study of mometasone furoate was carried out including acid and alkali hydrolysis, oxidation, thermal and photo-degradation. For mixture 1, the method was based on isocratic elution using a mobile phase consisting of (Acetonitrile: 3 mM Sodium lauryl sulfate) (60:40, v/v) at a flow rate of 1 ml min−1. Quantitation was achieved applying dual wavelength detection where mometasone furoate and its degradation products were detected at 247 nm and formoterol fumarate and its degradation product were detected at 214 nm at 30 °C. For mixture 2 and for the forced degradation study, separation was based on isocratic elution of mometasone furoate, its degradation products and salicylic acid on a reversed phase C8 column using a mobile phase consisting of acetonitrile:water:methanol:glacial acetic acid (60:30:10:0.1, v/v) at a flow rate of 2 mL min−1. Quantitation was achieved with UV detection at 240 nm. In addition, products from alkaline forced degradation of mometasone furoate were verified by LC–MS. Linearity, accuracy and precision were found to be acceptable over the concentration range of 10–800 μg mL−1 and 5–60 μg mL−1 for mometasone furoate and formoterol fumarate, respectively and over the concentration range of 5–320 μg mL−1 and 20–1280 μg mL−1 for mometasone furoate and salicylic acid, respectively. The two proposed methods could be successfully applied for the routine analysis of the studied drugs in their pharmaceutical preparations without any preliminary separation step

Validated Spectrophotometric Methods for Determination of Weakly UV absorbed Perindopril Arginine in Bulk and Combined Dosage Form

Five simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the oral antihypertensive drugs; perindopril arginine (PER) and amlodipine besylate (AML) in their combined dosage form. AML can be determined directly by measuring its absorbance at λmax357 nm. On the other hand PER was determined by five different methods. The first two methods, ratio derivative (RD) and Derivative subtraction coupled with the constant multiplication method (DS-CM), were performed using the ratio spectra. While the other three methods, amplitude factor (P-Factor), amplitude subtraction (AS) and modified amplitude subtraction (MAS), were developed based on derivative spectroscopy followed by mathematical manipulation. No preliminary separation steps were required for the proposed spectrophotometric methods. Linearity, accuracy and precision of the method was found to be acceptable over the concentration ranges of 20-80 μg/mL for PER and 5-40 μg/mL for AML. The proposed spectrophotometric methods were statistically compared to that of reference methods using one-way analysis of variance (ANOVA). The results showed that there was no significant difference between them