Novel HPLC-UV method for simultaneous determination of valsartan and atenolol in fixed dosage form; Study of green profile assessment

Current green capillary electrophoresis and liquid chromatography methods for analysis of pharmaceutical and biomedical samples (2019-2023) - A review

Separation analytical methods, including liquid chromatography (LC) and capillary electrophoresis (CE), in combination with an appropriate detection technique, are dominant and powerful approaches preferred in the analysis of pharmaceutical and biomedical samples. Recent trends in analytical methods are focused on activities that push them to the field of greenness and sustainability. New approaches based on the implementation of greener solvents, non-hazardous chemicals, and reagents have grown exponentially. Similarly, recent trends are pushed in to the strategies based on miniaturization, reduction of wastes, avoiding derivatization procedures, or reduction of energy consumption. However, the real greenness of the analytical method can be evaluated only according to an objective and sufficient metric offering complex results taking into account all twelve rules of green analytical chemistry (SIGNIFICANCE mnemonic system). This review provides an extensive overview of papers published in the area of development of green LC and CE methods in the field of pharmaceutical and biomedical analysis over the last 5 years (2019-2023). The main focus is situated on the metrics used for greenness evaluation of the methods applied for the determination of bioactive agents. It critically evaluates and compares the demands of the real applicability of the methods in quality control and clinical environment with the requirements of the green analytical chemistry (GAC). Greenness and practicality of the summarized methods are re-evaluated or newly evaluated with the use of the dominant metrics tools, i.e., Analytical GREEnness (AGREE), Green Analytical Procedure Index (GAPI), Blue Applicability Grade Index (BAGI), and Sample Preparation Metric of Sustainability (SPMS). Moreover, general conclusions and future perspectives of the greening procedures and greenness evaluation metrics systems are presented. This paper should provide comprehensive information to analytical chemists, biochemists, and it can also represent a valuable source of information for clinicians, biomedical or quality control laboratories interested in development of analytical methods based on greenness, practicality, and sustainability.

Development and validation of an effective and sensitive technique for nitrate determination in fruits and vegetables using HPLC/PDA

This study aims to develop an effective and sensitive HPLC (High Performance Liquid Chromatography) method to determine the nitrate concentration in fruits and vegetables (F & V) using a C18 column (ZORBAX Eclipse XDB-C18, 80Å, 250 × 4.6 mm, 5 μm (Agilent Technologies)) maintained at 40 0 C, a mobile phase made up of methanol and buffer (pentane sulfonic acid sodium salt solution), and a Photo Diode Array Detector (PDA) at 225 nm. The developed method is validated in terms of selectivity, linearity, accuracy, precision, suitability, the limit of detection (LOD), and the limit of quantification (LOQ) according to the European Union Decision 2002/657/EC. The result revealed that a ratio of 30: 70 of the organic modifier methanol and buffer with pH 2.8 shows the highest efficiency. The calibration curve shows linearity with a correlation coefficient (r) of 0.9985. The LOD and LOQ were found to be 2.26 mg/kg and 7.46 mg/kg. The recovery was in the range of 98.96-100.21%. Moreover, the greenness assessment scores of different approaches (eco-scale score of 76, AGREE score of 0.71, and few red shades in GAPI portray) were at a very excellent level. Thus, our developed method is fully validated and can determine the nitrate content in F & V.

Response surface methodology combined Box-Behnken design optimized green kinetic spectrophotometric and HPLC methods to quantify angiotensin receptor blocker valsartan in pharmaceutical formulations

The high-performance liquid chromatographic (HPLC) and kinetic spectrophotometric methods were established to compute valsartan (VAL) in pharmaceutical formulations. The spectrophotometric procedures adopted initial rate, fixed time, and equilibrium strategies to assess VAL. The method was based on the carboxylic acid group of the oxidized VAL with a mixture of potassium iodate (KIO₃) and potassium iodide (KI) at room temperature, producing a stable, yellow-coloured absorb at 352 nm. The critical parameters were optimized using green process optimization methodology such as Box-Behnken design (BBD) which belongs to response surface methodology (RSM). After the screening, experiments identified them as significant, and then three crucial factors were optimised: KI volume, KIO₃ volume, and reaction time against response as absorbance. The HPLC procedure was also optimized based on the desirability function on RSM-BBD. The parameters such as pH, methanol (%), and flow rate (ml/min) were optimized with the best responses: peak area, symmetry, and theoretical plates. The linearity of spectrophotometric and HPLC methods was within the range of 2-24 and 0.25-11.25 µg/ml, respectively. The developed procedures produced excellent accuracy and precision. The design of the experiment (DoE) setting explained and discussed the individual steps and the importance of independent and dependent variables used to develop the model and optimization. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Furthermore, Youden's robustness study was applied with factorial combinations of the preferred analytical parameters and explored their influence with alternative conditions. The analytical Eco-Scale score was calculated and was found a better option as green methods to quantify VAL. The results were reproducible with the analysis completed with biological fluid and wastewater samples.

Non-extractive spectrophotometric determination of valsartan in pure form and in pharmaceutical products by ion-pair complex formation with bromophenol blue and methyl red

Two simple, rapid, green non extractive spectrophotometric methods are described for the estimation of valsartan in tablet dosage form. The determination is based on the ion-pair formation using the dyes, bromophenol blue (BPB) and methyl red (MR). Valsartan forms ion-pair complex selectively with the dyes, as indicated by the formation of a coloured complex with BPB at pH 5.5 with λmax at 424 nm and MR at pH 4.3 with λmax at 494 nm. For both methods, optimal spectrophotometric conditions were established. The linear relationship was found between absorbance at λmax and concentration of drug in the range 8–24 µg/mL for BPB and 4–20 µg/mL for MR. Regression analysis of Beer’s law plot at 424 nm yielded the regression equation, y = 0.0102x + 01636 (BPB) and at 494 nm y = 0.0222x – 0.0063 (MR). High values of correlations coefficient (R2 = 0.9988 (BPB) and R2 = 0.9991 (MR)) and small values of intercept validated the linearity of calibration curve and obedience to Beer’s law. The LOD and LOQ values were calculated to be 1.03 µg/mL and 3.43 µg/mL respectively (BPB) and 0.68 µg/mL and 2.26 µg/mL respectively (MR). Intra-day and inter-day accuracy and precision, robustness were in acceptable limits. The proposed methods were applied for the quantification of valsartan in tablets pertaining to three commercial formulations. Analytical eco-scale for greenness assessment of the proposed spectrophotometric methods showed that both methods corresponds to excellent green analysis with a score of 89.

Spectrophotometric methods for the determination of lisinopril in medicines

Two simple, rapid and green spectrophotometric methods are described for the determination of lisinopril medicines. The determination is based on the reaction of the primary amino group of the lisinopril with ninhydrin in aqueous medium (Method I) and reaction on the carboxylic group of the lisinopril with copper (II) sulfate (Method II). For both methods, optimal spectrophotometric conditions were established. The linear relationship was found between absorbance at λmax and concentration of drug in the range 40–60 µg/mL (Method I) and 0.592–2.072 mg/mL (Method II). Regression analysis of Beer’s law plot at 400 nm yielded the regression equation, y = 7.4929x – 0.0545 (Method I) and at 730 nm y = 0.0443x – 0.0832 (Method II). High values of correlations coefficient (R2 = 0.9917 (Method I) and R2 = 0.999 (Method II)) and small values of intercept validated the linearity of calibration curve and obedience to Beer’s law. The LOD and LOQ values were calculated to be 6.91 µg/mL and 23.01 µg/mL respectively (Method I) and 0.11 mg/mL and 0.36 mg/mL respectively (Method II). Intra-day and inter-day accuracy and precision were in acceptable limits. The proposed methods were applied for the quantification of lisinopril in tablets pertaining to three commercial formulations. Analytical eco-scale for greenness assessment of the proposed spectrophotometric methods showed that both methods correspond to excellent green analysis.

Estimation of pitavastatin and ezetimibe using UPLC by a combined approach of analytical quality by design with green analytical technique

The current study explores a design and development of the simple, fast, green and selective novel method of UPLC to quantify pitavastatin and ezetimibe simultaneously. The combined approach of Green Analytical Method with Quality by Design-based risk assessment was done using the Ishikawa fishbone diagram followed by a rotatable central composite design used for the optimization. The optimal chromatographic separation was attained through a mobile phase of 72: 28% v/v ethanol and 0.1% orthophosphoric acid (pH 3.5), with a 0.31 mL min−1 flow rate. The developed UPLC-PDA method was sensitive and specific for pitavastatin and ezetimibe, with linearity ranging from 2 to 30, 10–150 μg mL−1 with an R2 of 0.9999 and 0.9997, respectively. The forced degradation study of stability-indicating assay results shows the degradation in respective stress conditions. The developed UPLC method was validated and found to have sensible results with good linearity, accuracy and precision. Further, the greenness was evaluated using five states of art metrics like NEMI, GAPI, AES, AMGS, and AGREE metrics and found the greenest results. Based on the results we concluded that the developed UPLC method could be efficient for the simultaneous determination of pitavastatin and ezetimibe in bulk and tablet dosage.