Kinetic spectrophotometric method for the determination of perindopril erbumine in pure and commercial dosage forms

Four ecofriendly spectrophotometric methods for the determination of perindopril through derivatization with sulphophtalein dyes: application to tablet analysis

Nowadays, there is a need to expand the bank of spectrophotometric methods for the determination of perindopril in dosage forms for the purposes of routine pharmaceutical analysis, which would be simple, express, «green» and inexpensive. In the present work, perindopril in tablets was quantified via a direct simple, «green», and non-extracting spectrophotometric approach based on the formation of ion-pair complexes with sulphophtalein dyes. The absorbances of the colored reaction products were registered at 405 nm (bromocresol green, BCG), 397 nm (bromocresol purple, BCP, and bromothymol blue, BTB) and 598 nm (bromophenol blue, BPB). To achieve the highest intensity of absorbance, optimum conditions were established by the screening of many experimental factors such as optimal concentration and volume of dyes, and the time consumed for the reaction. Beer's law was obeyed in the ranges of 0.44-3.96 µg/mL (BCG), 3.00-7.00 µg/mL (BCP), 4.00-12.00 µg/mL (BTB) and 0.44-3.52 µg/mL (BPB). All four methods were validated in accordance with ICH guidelines, confirming specificity and linearity, accuracy and precision, limits of detection and quantification, robustness. These validated methods provide a reliable and green approach for the quantitative analysis of perindopril in tablets, contributing to safer and more sustainable laboratory practices in pharmaceutical analysis.

Microchip isotachophoresis for green and sustainable pharmaceutical quality control: Method validation and application to complex pharmaceutical formulations

Universal microchip isotachophoresis (μITP) methods were developed for the determination of cationic and anionic macrocomponents (active pharmaceutical ingredients and counterions) in cardiovascular drugs marketed in salt form, amlodipine besylate and perindopril erbumine. The developed methods are characterized by low reagent and sample consumption, waste production and energy consumption, require only minimal sample preparation and provide fast analysis. The greenness of the proposed methods was assessed using AGREE. An internal standard addition was used to improve the quantitative parameters of μITP. The proposed methods were validated according to the ICH guideline. Linearity, precision, accuracy and specificity were evaluated for each of the studied analytes and all set validation criteria were met. Good linearity was observed in the presence of matrix and in the absence of matrix, with a correlation coefficient of at least 0.9993. The developed methods allowed precise and accurate determination of the studied analytes, the RSD of the quantitative and qualitative parameters were less than 1.5% and the recoveries ranged from 98 to 102%. The developed μITP methods were successfully applied to the determination of cationic and anionic macrocomponents in six commercially available pharmaceutical formulations.

Multiple green spectroscopic methods for erdosteine determination in bulk and dosage form with extensive greenness evaluation

Four simple, sensitive, economical, and eco-friendly spectrophotometric and spectrofluorimetric methods for the assay of erdosteine (ERD) in bulk and dosage form have been developed and validated as per the current ICH guidelines. Method I involved the addition of the powerful oxidizing agent, potassium permanganate to ERD and measuring the oxidation product at 600 nm. Another oxidizing agent; ceric ammonium sulfate was used in Method II where ERD is oxidized resulting in a decline in the absorbance intensity of cerium (IV) ions, measured at 320 nm. Similarly, Method III employed the use of ceric ammonium sulfate, However, the fluorescence intensity of the resulting cerium (III) ions was recorded at λex/λem 255/355 nm, respectively. Whereas in Method IV, ERD was added to acriflavine leading to a proportional decrease in its native fluorescence. Various reaction conditions affecting the intensity of measurement were attentively investigated, optimized, and validated. All the suggested methods did not require any tedious extraction procedures nor organic solvents. The implementation of the proposed methods in ERD assay resulted in linear relationships between the measured signals and the corresponding concentrations of ERD in the range of 1-6, 0.1-1.0, 0.01-0.1, and 10-100 μg/mL with LOD values 0.179, 0.024, 0.0027 and, 3.2 μg/mL for methods I, II, III and IV respectively. The suggested methods were successfully applied to ERD analysis in pure form and in commercial capsules. Furthermore, the eco-friendliness of the proposed methods was thoroughly checked using various greenness testing tools. Lastly, this work, not only presents highly sensitive, green, mix-and-read methods for ERD determination, but also, describes the determination of ERD spectrofluorimetrically for the first time in the literature.

Utilization of erythrosine B in spectrofluorimetric quenching analysis of amlodipine and perindopril in pharmaceutical and biological matrices

A spectrofluorimetric approach that is sensitive, simple, validated, and cost-effective has been proposed for the estimation of amlodipine (AML) and perindopril (PER) in their bulk powders, pharmaceutical formulations, and spiked human plasma. The recommended approach utilized the quantitative quenching effect of the two cited drugs on the fluorescence intensity of erythrosine B, as a result of complex binary reactions among each drug with erythrosine B at pH 3.5 (Teorell and Stenhagen buffer). The quenching of erythrosine B fluorescence was recorded at 554 nm after excitation at 527 nm. The calibration curve was detected in the range 0.25-3.0 μg ml-1 , with a correlation coefficient of 0.9996 for AML, and 0.1-1.5 μg ml-1 , with a correlation coefficient of 0.9996 for PER. The established spectrofluorimetric approach was validated for the estimation of the cited drugs with high sensitivity regarding International Council on Harmonization guidelines. Therefore, the established approach could be utilized for quality control of the cited drugs in their pharmaceutical formulations.

Three techniques for the determination of perindopril through derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole

In addition to its pure form, three accurate, rapid, and simple methods have been established for determining perindopril (PRD) in its tablet form. At pH 9.0 using a borate buffer, developing the three designated methods was successful according to the reaction between PRD and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and the formation of a chromogen (with a yellow color) measurable at 460 nm using the spectrophotometric method (Method I). In addition, the produced chromogen was assessed using the spectrofluorimetric method (Method II) at 535 nm following excitation at 461 nm. Afterward, the same reaction product was separated and determined using the HPLC method with fluorescence detection (Method III). A Promosil C₁₈ stainless steel column (Q7 5 mm particle size, 250-4.6 mm) has proven suitable for separation. The mobile phase adjustment was made at pH 3.0, with a 1.0 mL min ^-1 flow rate; its composition was methanol-sodium dihydrogen phosphate, 0.02 M (60: 40, v/v). Through concentration ranges of 5.0-60.0, 0.5-6.0, and 1.0-10.0 μg mL^-1, the calibration curves were rectilinear for Methods I, II, and III, respectively, with limits of quantification (LOQ) of 1.08, 0.16 and 0.19 μg mL^-1 as well as limits of detection (LOD) of 0.36, 0.05 and 0.06 μg mL^-1. The developed methods were implemented to estimate PRD in tablets, and a comparison between the obtained outcomes utilizing the developed methods as well as obtained from the official method revealed that they were comparable. The official BP method was based on dissolving PRD in anhydrous acetic acid and titrating with 0.1 M perchloric acid, then the potentiometric determination of the end-point. The designated methods were also implemented in content uniformity testing with satisfying results. The reaction pathway proposal was speculated, and according to ICH Guidelines, the statistical evaluation of the data was performed. The three proposed methods were confirmed to be green, eco-friendly and safe to environment using Green Analytical procedure index (GAPI) method.

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.

Spectrofluorimetric assay of amlodipine and perindopril in their raw materials, pharmaceutical formulations and spiked human plasma through the formation of complexes with Eosin Y

For quantitation of amlodipine (AML) and perindopril (PER) in their authentic, pharmaceutical formulations and spiked human plasma, a simple, sensitive, validated and inexpensive spectrofluorimetric method has been developed. The proposed method is developed to be based on quantitative quenching effect of two antihypertensive drugs on Eosin Y's native fluorescence which was achieved by developing binary complexes between each of the cited drugs in an acidic environment using acetate buffer (pH 4.4) with Eosin Y. Fluorescence quenching was recorded at 544 nm after excitation at 425 nm. For AML and PER, calibration curves were obtained over the range of 0.3–3.0 µg/mL and 0.2–2.0 µg/mL, respectively, with correlation coefficients of 0.9993 and 0.9995, respectively. The developed method was validated according to ICH guidelines. The proposed spectrofluorimetric method is regarded new and sensitive. As a result, the proposed method might be used to estimate the quality of the cited drugs in their pharmaceutical formulations and biological fluid.

In Vitro Kinetic Hydrolysis Study of Metronidazole Derivatives with Carvacrol and Eugenol Using Validated RP-HPLC Method

Background:

Prodrugs principle is widely used to improve the pharmacological and pharmacokinetic properties of some active drugs. Much effort was made to develop metronidazole prodrugs to enhance antibacterial activity and or to improve pharmacokinetic properties of the molecule or to lower the adverse effects of metronidazole.

Objective:

In this work, the pharmacokinetic properties of some of monoterpenes and eugenol pro metronidazole molecules that were developed earlier were evaluated in-vitro. The kinetic hydrolysis rate constants and half-life time estimation of the new metronidazole derivatives were calculated using the validated RP-HPLC method.

Method:

Chromatographic analysis was done using Zorbbax Eclipse eXtra Dense Bonding (XDB)-C18 column of dimensions (250 mm, 4.6 mm, 5 μm), at ambient column temperature. The mobile phase was a mixture of sodium dihydrogen phosphate buffer of pH 4.5 and methanol in gradient elution, at 1ml/min flow rate. The method was fully validated according to the International Council for Harmonization (ICH) guidelines. The hydrolysis process carried out in an acidic buffer pH 1.2 and in an alkaline buffer pH 7.4 in a thermostatic bath at 37ºC.

Results:

The results followed pseudo-first-order kinetics. All metronidazole prodrugs were stable in the acidic pH, while they were hydrolysed in the alkaline buffer within a few hours (6-8 hr). The rate constant and half-life values were calculated, and their values were found to be 0.082- 0.117 hr-1 and 5.9- 8.5 hr., respectively.

Conclusion:

The developed method was accurate, sensitive, and selective for the prodrugs. For most of the prodrugs, the hydrolysis followed pseudo-first-order kinetics; the method might be utilised to conduct an in-vivo study for the metronidazole derivatives with monoterpenes and eugenol.

Analytical Applications of Permanganate as an Oxidant in the Determination of Pharmaceuticals Using Chemiluminescence and Spectrophotometry: A Review

Background:

Potassium permanganate is a green and versatile industrial oxidizing agent. Due to its high oxidizing ability, it has received considerable attention and has been extensively used for many years for the synthesis, identification, and determination of inorganic and organic compounds.

Objective:

Potassium permanganate is one of the most applicable oxidants, which has been applied in a number of processes in several industries. Furthermore, it has been widely used in analytical pharmacy to develop analytical methods for pharmaceutically active compounds using chemiluminescence and spectrophotometric techniques.

Results:

This review covers the importance of potassium permanganate over other common oxidants used in pharmaceuticals and reported its extensive use and analytical applications using direct, indirect and kinetic spectrophotometric methods in different pharmaceutical formulations and biological samples. Chemiluminescent applications of potassium permanganate in the analyses of pharmaceuticals using flow and sequential injection techniques are also discussed.

Conclusion:

This review summarizes the extensive use of potassium permanganate as a chromogenic and chemiluminescent reagent in the analyses of pharmaceutically active compounds to develop spectrophotometric and chemiluminescence methods since 2000.