Validation of a novel UPLC-MS/MS method for estimation of metformin and empagliflozin simultaneously in human plasma using freezing lipid precipitation approach and its application to pharmacokinetic study.

A fast, sensitive one step UPLC ESI-MS/MS method was successfully applied for the simultaneous estimation of two concurrently administrated antidiabetic drugs, Metformin (MET) and Empagliflozin (EMPA) in human plasma. Metformin-d6 (MET-d6) and Empagliflozin-d4 (EMPA-d4) were utilized as internal standards. Extraction of the analytes from the human plasma was performed through acetonitrile precipitation technique followed by freezing the precipitated plasma proteins and lipids to minimize the matrix effect. Chromatographic analysis was developed on Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 50 mm) using isocratic elution mode. A mobile phase of formic acid (0.01 %): acetonitrile (70:30 v/v) with a flow rate of 0.3 mL/min achieved optimum separation. Multiple reaction monitoring (MRM) in positive ion mode, with transitions at (m/z) 130.14 →71.08 for (MET), 451.72 →71.29 for (EMPA), 136.03 →77.02 for (MET-d6), and 455.43 → 75.05 for (EMPA-d4) was used for quantification. The obtained linearity covered the concentration ranges of 10-1500 ng/mL and 2.0-250.0 ng/mL for MET and EMPA, respectively. The run time of the proposed Method didn't exceed 3.0 min allowing faster analysis and determination of larger number of samples per day without affecting accuracy and sensitivity. The presented chromatographic method could be successfully applied in pharmacokinetics studies and therapeutic monitoring of MET and EMPA in patients' plasma administrating fixed dose combination of both drug with high reproducibility and ruggedness.

pH assists simultaneous determination of folic acid and vitamin D3 in biological fluids using a novel Tb3+-acyclovir optical biosensor.

An innovative, simple and cost effective Tb3+-acyclovir photo probe was designed and used as a core for a spectrofluorometric approach to sensitively determine two vital biological compounds in different matrices. The Tb3+-acyclovir complex displays a characteristic electrical band with λ em at 545 nm with significant luminescence intensity, which is quenched in the presence of folic acid and vitamin D3 at pH 5.0 and 9.0, respectively. The conditions were optimized and the best solvent for operation was found to be acetonitrile and λ ex at 340 nm. folic acid was successfully estimated in tablet dosage form, urine and serum in the concentration range of 2.28 × 10-6 to 1.49 × 10-9 mol L-1. Vitamin D3 was also assessed in serum samples using the same optimal conditions within the concentration range of 3.2 × 10-9 to 1.0 × 10-6 mol L -1. The proposed luminescence method was validated in accordance with ICH guidelines and found to be accurate, precise and specific and free from any interferences. The cost effectiveness and applicability of the method make it a good choice for routine analysis of the two compounds and early diagnosis of chronic diseases associated with abnormalities in their physiological levels.

Highly Selective Optical Sensor Eu (TTA)3 Phen Embedded in Poly Methylmethacrylate for Assessment of Total Prostate Specific Antigen Tumor Marker in Male Serum Suffering Prostate Diseases.

A low-cost, simple, and highly selective method was used for the assessment of total prostate specific antigen (tPSA) in the serum of prostate cancer patients. This method is based on quenching the intensity of luminescence displayed by the optical sensor Eu (TTA)3 phen/poly methylmethacrylate (PMMA) thin membrane or film upon adding different concentrations of tPSA. The luminescent optical sensor was synthesized and characterized through absorption, emission, scanning electron microscopy (SEM), and x-ray diffraction (XRD), and is tailored to present red luminescence at 614 nm upon excitation at 395 nm in water. The fabricated sensor fluorescence intensity is quenched in the presence of tPSA in aqueous media. The fluorescence resonance energy transfer (FRET) is the main mechanism by which the sensor performs. The sensor was successfully utilized to estimate tPSA in the serum of patients suffering prostate cancer in a time and cost effective way. The statistical results of the method were satisfactory with 0.0469 ng mL-1 as a detection limit and 0.99 as a correlation coefficient.

Alpha fetoprotein assessment by using a nano optical sensor thin film binuclear Pt-2-aminobenzimidazole-Bipyridine for early diagnosis of liver cancer.

A simple, precise and sensitive method in which, a nano optical sensor binuclear Pt-2-aminobenzimidazole-bipyridine, Pt(abi)(bpy) complex doped in sol gel is used for the early diagnosis of liver cancer. The idea depends on the assessment of the concentration of alpha fetoprotein (AFP) in the serum samples of different liver patients. The nano binuclear Pt(abi)(bpy) has strong emission spectrum upon excitation at 380 nm in distilled water. The assessment of alpha fetoprotein (AFP) depends on the quenching of the emission spectrum of the optical sensor at 610 nm in water by the alpha fetoprotein (AFP). The calibration plot was achieved over the concentration 5.0 - 350 U L-1 with a correlation coefficient of 0.997 and a detection limit of 3.0 U L-1. The method was used satisfactorily for the diagnosis of liver cancer in a number of serum samples collected from various patients and health state; healthy (≤ 30 U L-1), Virus B (42.2-69.5 U L-1), Virus C (75.7-98.4 U L-1), Cirrhosis (112-147 U L-1) and HCC (185.2-349.6 U L-1). Furthermore, the assessment of the alpha-fetoprotein by the proposed method increases its sensitivity (92.88%) and specificity (91.41%) for early diagnosis of HCC.