Micelle-Incorporated Liquid Chromatography in the Light of Green Chemistry: An Application for the Quality Control Analysis of Anti-Platelet Fixed-Dose Combinations.

BACKGROUND: Oral anti-platelet agents are the cornerstone of the treatment of multiple cardiovascular diseases and in the long-term prevention of their recurrence. OBJECTIVE: In the present work, we report a method based on micellar liquid chromatography coupled with ultraviolet detection (MLC/UV), for the simultaneous quantification of combined anti-platelet therapy namely, clopidogrel bisulfate (CPS), aspirin (ASP), together with salicylic acid (SA), in their pharmaceutical dosage form. METHODS: The incorporation of 0.1M polyoxyethylene 23 lauryl ether (Brij-35) as a surfactant into the mobile phase improved solute-mobile phase interaction allowing for minimal organic solvent utilization, enhanced resolution, and rapid analysis (7 min). Furthermore, we performed a comprehensive evaluation of the environmental impact caused by our procedures versus previously reported analytical procedures applied in the determination of CPS and ASP. The evaluation was made using the Eco-scale tool. RESULTS: The results of the developed method indicated the superiority of our procedures in terms of greenness without compromising the quality of performance characteristics. The method was linear in the range of 1-100 µg/mL with limits of detection of 0.28, 0.32, and 0.29 µg/mL for CPS, ASP, and SA, respectively. The developed method can also be utilized to test the purity and the stability of ASP in pharmaceutical formulations through monitoring SA as its main degradation product. CONCLUSION: The MLC/UV method was successfully applied to the quantitative analysis of CPS, ASP together with SA-as a main degradation product of ASP-in their pharmaceutical dosage form. HIGHLIGHTS: The developed method was successfully applied for the determination of clopidogrel bisulfate (CPS), aspirin (ASP), together with salicylic acid (SA), in their pharmaceutical dosage form.

Synchronous Spectrofluorimetry Coupled with Third-Order Derivative Signal Processing for the Simultaneous Quantitation of Telmisartan and Chlorthalidone Drug Combination in Human Plasma.

This study is the first to develop and optimize a method for the simultaneous determination of chlorthalidone (CLT) and telmisartan (TEL) in, human plasma samples as well as in their newly released pharmaceutical tablet form, (Telmikind-CT 40®). The method is based on measuring fluorescence intensity, employing synchronous fluorescence mode coupled to third-order derivative signal processing, 0.5% w/v cetyl trimethyl ammonium bromide was used as cationic surfactant to enhance the fluorescence signal intensity and improve method sensitivity. The third-order derivative synchronous spectra of CLT and TEL are well separated with two zero-crossing points which allowed for the determination of CLT and TEL at 362 nm and 351 nm, respectively. Different experimental parameters were carefully investigated and optimized, calibration curves were constructed over concentration ranges of 20-1200 ng.mL-1 and 5-800 ng.mL-1 for CLT and TEL respectively. The developed method is simple and rapid, analytical parameters were validated according to ICH guidelines and high sensitivity was achieved as represented by limits of detection (LOD) of 4.69 and 1.58 ng.mL-1 for CLT and TEL respectively.

Analysis of quinary therapy targeting multiple cardiovascular diseases using UV spectrophotometry and chemometric tools.

Herein, UV spectrophotometry assisted by multivariate chemometric analysis have been presented for quantitative determination of complex quinary therapy containing atenolol, ramipril, hydrochlorothiazide, simvastatin and aspirin without any prior separation. Such combination is very useful for treating various cardiovascular diseases (CVD) including high blood pressure, hypercholesterolemia in addition to its antiplatelet aggregating activity. Calibration (15 samples) and validation (10 samples) sets were prepared of different concentrations for these drugs via implementing partial factorial experimental design. The zero order UV spectra of these sets were recorded and then subjected for further chemometric analysis. Partial least square (PLS) with/without variable selection procedure i.e. genetic algorithm (GA) were employed to untangle the UV spectral overlapping of these mixtures. The performance of these chemometric techniques were compared in terms of accuracy and predictive abilities using cross-validation and external validation methods. It was found that PLS provides good recoveries with prompt predictive ability albeit GA-PLS exhibited better analytical performance owing to its capability to remove redundant variables i.e. the number of absorbance variables had been reduced to about 19-28%. The developed methods allowed reliable determination of such complex therapy in its laboratory prepared mixtures and pharmaceutical preparation within comparable results to those reported by HPLC method, posing these chemometric methods as valuable and indispensable analytical tools in in-process testing and quality control analysis of many pharmaceutical compounds targeting CVD.

Separation-free spectrophotometric platforms for rapid assessment of combined antiplatelet therapy in complex matrices.

Aim: To develop simple and rapid UV-spectrophotometric platforms for the simultaneous quantification of a binary mixture containing clopidogrel bisulphate (CPS) and aspirin (ASP) in complex matrices without prior separation. Experimental: Five mathematical models namely ratio-difference method, mean centering of the ratio spectra, dual wavelength, induced dual wavelength and H-Point Standard Addition method, were utilized for resolving spectral overlap by mathematical processing of ratio and zero-order absorption spectra. Analytes were extracted from tested matrices (whole blood, pharmaceutical formulations and dissolution media buffer) and quantified using the proposed methods. The methods were validated according to ICH guidelines. Results: The developed methods demonstrated limits of detection ranging from 0.67 to 1.09 µg/ml-1 for CPS and 0.49 to 0.71 µg.ml-1 for ASP. All proposed methods allowed for reliable determination of CPS and ASP in complex matrices within reported reference ranges, indicating their potential application for therapeutic drug monitoring and quality control testing.

Towards a personalized approach to aromatase inhibitor therapy: a digital microfluidic platform for rapid analysis of estradiol in core-needle-biopsies.

Despite advances in breast cancer prevention and treatment, variability in patient-response has revealed the need for a more "personalized" approach to medicine, in which treatments are tailored to each patient's biology. Motivated by this idea, we introduce a technique that allows for quantification of small-molecule analytes directly from core needle biopsy (CNB) tissue samples on a miniaturized platform. The new technique, powered by digital microfluidics, integrates tissue-liquid extraction and magnetic bead-based competitive immunoassay for quantification of estradiol in milligram-sized CNB samples. Each measurement (from start to finish) requires ∼40 minutes, a duration consistent with a visit to a doctor's office. The performance of the new technique was validated by the gold-standard analysis method (high performance liquid chromatography coupled to tandem mass spectrometry), and was applied to evaluate human patient samples before and after a course of treatment with aromatase inhibitor therapy. We propose that the new technique has great potential for eventual use for fast, automated, and quantitative analysis of biomarkers in tissue samples, towards a personalized medicine approach.

A microfluidic technique for quantification of steroids in core needle biopsies.

Core needle biopsy (CNB) sampling is known to be inexpensive and minimally invasive relative to traditional tissue resectioning. But CNBs are often not used in analytical settings because of the tiny amount of sample and analyte. To address this challenge, we introduce an analytical method capable of multiplexed steroid quantification in CNB samples-those studied here ranged in mass from 2 to 8 mg. The new method uses digital microfluidics to extract steroids from CNB tissue samples (including a solid-phase extraction cleanup step) followed by analysis by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The method has limits of detection of 3.6, 1.6, 5.8, and 8.5 fmol for estradiol, androstendione, testoterone, and progesterone, respectively. We propose that future generations of this method may be useful for regular quantification of steroids in core needle biopsy samples of breast tissue to inform dosage and timing of antihormone or hormone replacement therapies as part of a personalized medicine approach to treating a variety of hormone-sensitive disorders.