Simultaneous Determination of Tizanidine, Nimesulide, Aceclofenac and Paracetamol in Tablets and Biological Fluids Using Micellar Liquid Chromatography

Earth-friendly micellar UPLC technique for determination of four hypoglycemic drugs in different pharmaceutical dosage forms and spiked human plasma

A novel, sensitive, and green micellar UPLC method was proposed and validated for the simultaneous determination of four hypoglycemic agents used in type II diabetes mellitus treatment namely, pioglitazone, alogliptin, glimepiride, and vildagliptin. The developed UPLC method was successfully applied for quantitative analysis of these drugs in bulk, in pharmaceutical formulations, and in spiked human plasma. Chromatographic separation was carried out on a Kinetex® 1.7 μm XB-C18 100 Å (50 × 2.1 mm) column, using a degassed and filtered mixture of (0.1 M SDS- 0.3% triethyl amine- 0.1% phosphoric acid (pH 6)) and n-propanol (85:15 v/v), at a flow rate of 0.2 mL/min. The experimental conditions of the suggested method were well investigated and optimized. The newly developed micellar UPLC method is capable of determining different dosage forms at the same time with the same solvents, saving time and effort. The method was found to be efficiently applicable in spiked human plasma and could be extended to study the pharmacokinetics of the cited drugs in real human plasma samples. The greenness of the developed method was evaluated by applying the Eco-scale scoring tool, which verified the excellent greenness of the analytical method.

On-off Fluorescent Switching of Excitation-independent Near-ultraviolet Emission Carbon Nanobelts for Ultrasensitive Detection Nimesulide in Pharmaceutical Tablet

Here, we present an excellent strategy of unmodified near-ultraviolet fluorescence nitrogen doping carbon nanobelts (NFNCBs) for detecting nimesulide (Nim). After a simple hydrothermal process of uric acid and hydroquinone in DMF solvent, NFNCBs shows the shape of corroded stalactite-like composed of nanobelts aggregates, near-ultraviolet luminescence and a narrowed full width at half maximum. This could improve/change the electronic properties and surface chemical active site, as the result of a sensitive response to Nim. By employing this sensor, the quantitative measurement displays a linear range of 2.0 nM - 100.0 μM with a lower detection limit of 0.21 nM (3σ/k) for Nim. Our work has provided a high selectivity for Nim, which may be capable for pharmaceutical sample analysis in real tablets. Furthermore, the results concerning the recoveries (96.3 - 106.2%) for real sample analysis indicate that this nanoprobe might expand a good avenue to design an effective luminescence nanoprobe for other biologically related drugs.

Cyclodextrin-Modified Micellar UPLC for Direct, Sensitive and Selective Determination of Water Soluble Vitamins in Milk

Cyclodextrin-modified micellar ultra pressure liquid chromatography (CD-MUPLC) was firstly developed and directly applied to the simultaneous determination of water-soluble vitamins thiamine hydrochloride (VB1), pyridoxine hydrochloride (VB6) and ascorbic acid (VC) in milk samples. A hybrid isocratic mobile phase consisting of β-cyclodextrin (β-CD, 5.0 mmol L-1) and cetyltrimethylammonium bromide (CTAB, 0.1 mol L-1) in the presence of acetic acid (0.1 mol L-1) at pH 2.9 on a RP-C18 column at 25.0°C was successfully used. The separation of vitamins was achieved in less than 10 min at a 0.2 mL min-1 flow rate showing adequate linearity at 245 nm in the ranges of 5.0-500.0 μg L-1 for VB1, 5.0-1000.0 μg L-1 for VB6 and 5.0-10000.0 μg L-1 for VC with coefficients of variation (r2) of 0.9999, 0.9987 and 0.9971, respectively. In addition, limits of detection obtained were 0.885, 1.352 and 1.358 μg L-1 and limits of quantification were 2.681, 4.096 and 4.115 μg L-1 for VB1, VB6 and VC, respectively. The high sensitivity of the proposed CD-MUPLC-UV method permitted its applications to the determination of water-soluble vitamins VB1 (32-488 μg L-1), VB6 (82-95 μg L-1) and VC (790-45000 μg L-1) in breast and bovine milk samples. The relative standard deviations and recoveries ranged between 0.07 and 2.14% and between 85.27 and 114.8%, respectively, indicating the accurate and precise measurements without any negative impact of matrix. The current analytical method illustrated several advantages including direct, sensitive, selective and non-consuming organic solvents over the hitherto published methods. These features could be attributed to the four-point competitive interactions among analytes, pseudostationary phases and modified C18 stationary phases.

Development and Validation of a Versatile UPLC-PDA Method for Simultaneous Determination of Paracetamol, Tizanidine, Aceclofenac, and Nimesulide in Their New Combinations

A simple, rapid, and validated UPLC method was developed for the simultaneous quantitation of paracetamol (PAR), tizanidine (TIZ), aceclofenac (ACF), and nimesulide (NIM) either in pure forms or in their different tablet dosage forms. Chromatographic separation was attained on an ACQUITY UPLC™ BEH C18 column (100 mm × 2.1 mm, 1.7 μm) with a mobile phase consisting of 20 mM phosphate buffer (pH 7.0) : acetonitrile in the proportion (60 : 40 v/v) isocratically pumped at a flow rate of 1.25 mL·min^-1, and detection was monitored at 305 nm. All analytes were separated simultaneously at a retention time (t_r) of 1.42, 2.31, 3.63, and 5.62 min for PAR, TIZ, ACF, and NIM, respectively, with a total run time less than 6.0 min. The proposed method was validated according to ICH guidelines with respect to accuracy, precision, linearity, limit of detection, limit of quantitation, and robustness. Linearity was obtained over a concentration range of 81.25-487.5, 0.5-3.5, 25-150, and 25-150 µg·mL^-1 for PAR, TIZ, ACF, and NIM, respectively. The development method can be successfully employed in QC laboratories for the routine analysis of the investigated drugs in their new combination.