Browsing by Author "Zakaria, Ola"

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    A Comparative Study of Smart Spectrophotometric Methods and a Densitometric Method for Simultaneous Determination of Binary Mixture of Canagliflozin and Metformin Hydrochloride
    (TAYLOR & FRANCIS LTD, 2018) S Elshahed, Mona; Mohamed, Dalia; Nasr, Tamer; Aboutaleb, Nageh; Zakaria, Ola
    Simple and sensitive Spectrophotometric methods and a densitometric thin layer chromatographic method (TLC) are developed and validated for simultaneous determination of binary mixture of metformin hydrochloride (MET) and canagliflozin (CFZ) in combined dosage form. Three spectrophotometric methods manipulating ratio spectra namely ratio subtraction, ratio difference and derivative ratio are used for the determination of MET in the presence of CFZ without preliminary separation, while CFZ is directly determined by measuring its absorbance at λmax 290 nm. The calibration curves follow Beer's law in the concentration range of 1 - 20 and 1 - 30 μg/mL for MET and CFZ respectively. A simple TLC method is developed where separation is performed on TLC silica gel plates 60F254 using toluene: Methylene chloride: methanol: water: glacial acetic acid in the volume ratio (20:15:15:1:0.25) as a mobile phase. Rf values are 0.55 ± 0.05 for CFZ and 0.21 ± 0.03 for MET, the linearity ranges are 0.3-4.5 and 0.5-5.5 μg/band for CFZ and MET respectively. The developed methods are successfully applied for the simultaneous determination of MET and CFZ in bulk and pharmaceutical formulation.
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    Novel LC-MS/MS method for analysis of metformin and canagliflozin in human plasma: application to a pharmacokinetic study
    (BMC, 2019-07) Mohamed, Dalia; Elshahed, Mona S; Nasr, Tamer; Zakaria, Ola
    Highly sensitive and selective liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous estimation of the recently approved oral hypoglycemic mixture; metformin (MET) and canagliflozin (CFZ) in human plasma using propranolol HCl (PPL) and tadalafil (TDF) as internal standards (IS), respectively. Analytes were extracted using protein precipitation induced by acetonitrile then liquid-liquid extraction was performed using ethyl acetate. Reversed phase HPLC was carried out using C18 analytical column (50 mm x 4.6 mm i.d., 5 mu m) with a simple isocratic mobile phase composed of 0.1% formic acid and acetonitrile (60:40, v/v). Detection was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring (MRM), with the transitions of m/z 130.2 -> 60.1, m/z 462.3 -> 191.0, m/z 260.2 -> 183.0 and m/z 390.2 -> 268.2 for MET, CFZ, PPL and TDF, respectively, in the positive ion mode. The analysis was carried out within 5 min over a linear concentration range of 50-5000 ng/mL for MET and 10-1000 ng/mL for CFZ. The method was validated in accordance with the FDA guidelines for bioanalytical method. All obtained recoveries were higher than 90.0% while the accuracy was in the range of 88.14-113.05% and the relative standard deviation was below 10.0% for all investigated drugs by the proposed method. The achieved promising results has allowed for the successful application of the developed LC-MS/MS method to a pharmacokinetic study of the target drugs after their oral administration to Egyptian healthy volunteers. The pharmacokinetic study was accomplished after the agreement of the ethics committee.