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A novel chemometric strategy was implemented in the development of a new ultraperformance liquid chromatography method for the quantitative estimation of guaifenesin and pseudoephedrine hydrochloride in a two-component syrup formulation with minimal experimental effort, time and reagent. A full factorial design with three factors was investigated to find optimal working conditions of chromatographic factors (column temperature, flow rate, and 0.1 M H3PO4% in mobile phase) that affect the chromatographic separation. Then, optimum experimental conditions providing adequate separation of the analyzed drug substances within the short runtime were determined. Under optimal experimental conditions, the retention times for guaifenesin and pseudoephedrine hydrochloride were obtained as 0.817 and 1.430 min, respectively. In the optimized RP-UPLC method, chromatographic response was reported as a linear function of concentration between 5.0 and 80.0 μg/mL for guaifenesin and 10.0-90.0 μg/mL for pseudoephedrine hydrochloride. The proposed method was carefully validated and successfully applied to quality control and analysis of a cough syrup preparation containing guaifenesin and pseudoephedrine hydrochloride. Consequently, the proposed reversed-phase ultraperformance liquid chromatography method provided an opportunity to quantify relevant drugs with small amount of reagents and short runtime., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Two simple validated and highly selective methods for analysis of paracetamol, codeine, guaifenesin and pseudoephedrine or phenylephrine quaternary mixtures were developed. The first method is a high performance liquid chromatography with diode array detection method where separation was successful using Agilent C18 (150 × 4.6 mm) column, gradient elution of phosphate buffer pH 3, methanol and acetonitrile and diode-array detection at 210 nm. The second method is a HPTLC method followed by densitometric measurement of the spots at 257 nm. Separation was carried out on Merck HPTLC aluminum sheets of silica gel using methylene chloride: methanol: glacial acetic acid: ammonia (17.8: 1.68: 0.4: 0.12, v/v) mobile phase. The methods were applied successfully for analysis of both quaternary mixtures in laboratory-prepared tablets and also validated in regards to linearity, precision, accuracy, sensitivity and stability., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

A sensitive, accurate and selective high performance thin layer chromatography (HPTLC) method was developed and validated for the simultaneous determination of paracetamol (PAR), its toxic impurity 4-aminophenol (4-AP), pseudoephedrine HCl (PSH) and loratidine (LOR). The proposed chromatographic method has been developed using HPTLC aluminum plates precoated with silica gel 60 F254 using acetone-hexane-ammonia (4:5:0.1, by volume) as a developing system followed by densitometric measurement at 254 nm for PAR, 4-AP and LOR, while PSH was scanned at 208 nm. System suitability testing parameters were calculated to ascertain the quality performance of the developed chromatographic method. The method was validated with respect to USP guidelines regarding accuracy, precision and specificity. The method was successfully applied for the determination of PAR, PSH and LOR in ATSHI(®) tablets. The three drugs were also determined in plasma by applying the proposed method in the ranges of 0.5-6 µg/band, 1.6-12 µg/band and 0.4-2 µg/band for PAR, PSH and LOR, respectively. The results obtained by the proposed method were compared with those obtained by a reported HPLC method, and there was no significance difference between both methods regarding accuracy and precision., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

In the present study, a simple strategy based on solid-phase extraction (SPE) with a cation exchange sorbent (Finisterre SCX) followed by fast high-performance liquid chromatography (HPLC) with diode array detection coupled with chemometrics tools has been proposed for the determination of methamphetamine and pseudoephedrine in ground water and river water. At first, the HPLC and SPE conditions were optimized and the analytical performance of the method was determined. In the case of ground water, determination of analytes was successfully performed through univariate calibration curves. For river water sample, multivariate curve resolution and alternating least squares was implemented and the second-order advantage was achieved in samples containing uncalibrated interferences and uncorrected background signals. The calibration curves showed good linearity (r(2) > 0.994).The limits of detection for pseudoephedrine and methamphetamine were 0.06 and 0.08 μg/L and the average recovery values were 104.7 and 102.3% in river water, respectively., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Pseudoephedrine and cetirizine have been combined in dosage forms with more therapeutic benefits when compared with single-drug treatment. The current manuscript reports the development of the first capillary zone electrophoresis (CZE) assay method for that combination. The effects of pH and buffer concentration on resolution, noise, migration time and peak area were examined employing experimental design approach. The analytes were electropherographed into a 50.2 cm-long and 50 µm i.d. fused-silica capillary column using 10 mmol/L borate at pH 8.3 with a potential of 25 kV at 25°C and UV detection at 214 nm. The method was successfully validated in order to verify its suitability for pharmaceutical analysis for the purposes of quality control. Over previous high-performance liquid chromatographic methods, the current CZE method features the benefits of the use of cost-effective electrolyte, besides high sample throughput (11 samples/h). Furthermore, other analytical results including linear dynamic ranges, recovery (96.9-98.1%), intra- and interday precision (relative standard deviation ≤ 1.70%) as well as the limits of detection and quantification (≤2.65 µg/mL) were all satisfactory for the intended purpose., (© The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

A simple and rapid capillary electrophoresis method was developed for the separation and determination of ephedrine (E) and pseudoephedrine (PE) in a buffer solution containing 80 mM of NaH2PO4 (pH 3.0), 15 mM of β-cyclodextrin and 0.3% of hydroxypropyl methylcellulose. The field-amplified sample injection (FASI) technique was applied to the online concentration of the alkaloids. With FASI in the presence of a low conductivity solvent plug (water), an approximately 1,000-fold improvement in sensitivity was achieved without any loss of separation efficiency when compared to conventional sample injection. Under these optimized conditions, a baseline separation of the two analytes was achieved within 16 min and the detection limits for E and PE were 0.7 and 0.6 µg/L, respectively. Without expensive instruments or labeling of the compounds, the limits of detection for E and PE obtained by the proposed method are comparable with (or even lower than) those obtained by capillary electrophoresis laser-induced fluorescence, liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. The method was validated in terms of precision, linearity and accuracy, and successfully applied for the determination of the two alkaloids in Ephedra herbs.

This work describes the development, validation and application of a simple and reliable high-performance liquid chromatography-diode array detection (HPLC-DAD) procedure for the analysis of two pharmaceutical mixtures. The first mixture contains the antihistaminic drug ebastine (EBS) and the famous sympathomimetic drug pseudoephedrine hydrochloride (PSD), and the second mixture is composed of EBS and another sympathomimetic agent, phenylephrine hydrochloride (PHR). Effective chromatographic separation of EBS, PSD and PHR was achieved using a Zorbax SB-C8 (4.6 × 250 mm, 5 μm) column with gradient elution of the mobile phase composed of 0.05M phosphoric acid and acetonitrile. The gradient elution started with 20% (by volume) acetonitrile, ramped up linearly to 90% in 5 min, then kept constant until the end of the run. The mobile phase was pumped at a flow rate of 1 mL/min. The multiple wavelength detector was set at 254 (for EBS and PSD) and 274 nm (for PHR) and quantification of the analytes was based on measuring their peak areas. The retention times for PHR, PSD and EBS were approximately 2.5, 2.9 and 7.1 min, respectively. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, ranges, precision, accuracy, selectivity, robustness and detection and quantification limits. Calibration curves were linear in the ranges 5-100, 100-1,000 and 10-200 µg/mL for EBS, PSD and PHR, respectively, with correlation coefficients > 0.9996. The validated HPLC method was applied to the analysis of the two pharmaceutical mixtures in laboratory-made tablets in which the analytes were successfully quantified with good recovery values and no interfering peaks were encountered from the inactive ingredients. Finally, the proposed method made use of DAD as a tool for peak identity and purity confirmation.

Orthogonal design (OD) was employed to optimize the separation condition of flow injection-capillary electrophoresis (FI-CE). In order to compare the optimum condition, uniform design and univariate approach were also adopted. The influences of variables such as buffer pH, buffer concentration, acetonitrile (ACN) percentage, and separation voltage were discussed. The optimum separation condition was established. The limits of detection were 1.94 × 10(-2), 6.40 × 10(-3), 1.16 × 10(-2) and 1.94 × 10(-2) μg/mL for dextromethorphan hydrobromide (Dex), chlorphenamine hydrogen maleate (Chl), pseudoephedrine hydrochloride (Pse), and paracetamol (Par), respectively. The RSDs of peaks areas were less than 2.0%. The results showed the OD was an effective method among experimental designs for optimizing the separation conditions of CE. The optimum condition was used for separation and determination of Dex, Chl, Pse, and Par in cold medicines. The average recovery was between 96.68-101.25%.