Different spectrophotometric methods for simultaneous determination of lesinurad and allopurinol in the new FDA approved pharmaceutical preparation; additional greenness evaluation

Derivative spectroscopy and wavelet transform as green spectrophotometric methods for abacavir and lamivudine measurement

Herein, two different sustainable and green signal processing spectrophotometric approaches, namely, derivative spectroscopy and wavelet transform, have been utilized for effective measurement of the antiretroviral therapy abacavir and lamivudine in their pharmaceutical formulations. These methods were used to enhance the spectral data and differentiate between the absorption bands of abacavir and lamivudine in order to accurately measure their concentrations. For determining abacavir and lamivudine, the first derivative spectrophotometric method has been applied to the zero-order and ratio spectra of both drugs. The same approach has been tested using the continuous wavelet transform method where a second order 2.4 of rbio and bior wavelet families were found to be optimum for measuring both drugs. Validation of the proposed methods affirmed their reliability in terms of linearity over the concentration range 1.5-30 µg/mL and 1.5-36 µg/mL for abacavir and lamivudine, respectively, precision (RSD < 2 %), and accuracy with mean recoveries ranging between 98 % and 102 %. Additionally, these spectrophotometric methodologies were applied to real pharmaceutical preparations and yielded results congruent with a prior chromatographic method. Most prominently, the proposed methods stood out for their greenness and sustainability with 97 points as evaluated by the analytical eco-scale method and a score value of 0.79 as analyzed by AGREE method, thereby making them suitable for resource-limited settings and highlighting the potential for broader application of green analytical methods in pharmaceutical analysis.

Exploring the role of copper and zinc in chronic otitis media: A novel spectrofluorometric method for precise determination and association study

Chronic otitis media is a common condition characterized by fluid accumulation in the middle ear, leading to a perforated eardrum and persistent middle ear drainage. Despite its impact on global health, the role of heavy metals, particularly copper and zinc, in its development and progression remains understudied. Herein, a spectrofluorometric method was developed for the precise determination of copper and zinc in human plasma samples and investigate their association with chronic otitis media. The method involves the use of the fluorescent probe 6,7-dihydroxy-4-phenylcoumarin to selectively quantify copper through fluorescence quenching and zinc through fluorescence enhancement with a remarked bathochromic shift. The method was validated and exhibited good linearity over a concentration range of 100-3000 ng/mL for copper and 200-5000 ng/mL for zinc. Application of the method to healthy volunteers and patients with chronic otitis media revealed significantly decreased copper and zinc levels in patients with chronic otitis media compared to the healthy individuals. These findings shed light on the involvement of copper and zinc in the pathogenesis of chronic otitis media and open avenues for additional treatment approaches.

Application of a nucleophilic substitution reaction for spectrofluorimetric determination of aripiprazole in pharmaceutical dosage form and plasma matrix; greenness assessment

Aripiprazole is an antipsychotic medicine used to treat a variety of mental disorders, including irritability linked with autism disorder in children. Herein, a green and highly sensitive spectrofluorimetric method was developed for the determination of aripiprazole in pharmaceutical dosage form and plasma matrix. The method based on the formation of a fluorescent adduct from the nucleophilic substitution reaction of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-chloride) with aripiprazole, which can be detected at 542 nm following excitation at 481 nm. Factors that affect the development and fluorescence sensitivity of the reaction product were investigated and optimized. The reaction yielded the most optimal fluorescence responses when it was performed using 1.5 mL of 0.2 % w/v NBD-chloride, 1.5 mL of borate buffer pH 9, heating at 80 °C for 20 min, and ethanol as a diluting solvent. The method was validated as per ICH guidelines for analytical and bioanalytical procedures. Good linearity was established between the fluorescence responses of the reaction product and aripiprazole concentrations in the range of 100-1200 ng/mL with adequate accuracy and precision results. The applied method was very sensitive and selectively determined aripiprazole in pharmaceutical and plasma matrices with no interferences. Furthermore, the compliance of the proposed method with the principles of green analytical chemistry was evaluated in comparison with the reported method using analytical eco-scale and AGREE metrics. The outputs proved that the proposed method complied more with the principles of green analytical chemistry than the reported method.

Spectrofluorometric quantitative analysis of aripiprazole based on quenching of natural derived carbon quantum dots in spiked human plasma

Autism spectrum disorder is a significant concern worldwide, particularly in Middle Eastern countries. Aripiprazole, a psychiatric medicine that works as a partial agonist at D2 receptors, is often used for autism-related behavior issues in children. Monitoring the therapy of aripiprazole could enhance the safety and effectiveness of treatment for autistic individuals. The purpose of this study was to develop a highly sensitive and environmentally friendly method for analysis of aripiprazole in plasma matrix. To achieve this, water-soluble N-carbon quantum dots were produced from a natural green precursor, guava fruit, and used in fluorescence quenching spectroscopy to determine the presence of aripiprazole. The synthesized dots were analyzed and characterized using transmission electron microscopy and Fourier transform infrared spectroscopy, and they showed a strong fluorescence emission peak at 475 nm. The proposed method was validated according to ICH M10 guidelines and was shown to be highly sensitive, allowing for nanoscale determination of aripiprazole in plasma matrix. Additionally, the method was compared to a previously reported spectrophotometric method, and it was found to be more sensitive and consistent with the principles of green analytical chemistry.

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.

Higher sensitive selective spectrofluorometric determination of ritonavir in the presence of nirmatrelvir: application to new FDA approved co-packaged COVID-19 pharmaceutical dosage and spiked human plasma

BACKGROUND

Ritonavir was recently combined with nirmatrelvir in a new approved co-packaged medication form for the treatment of COVID-19. Quantitative analysis based on fluorescence spectroscopy measurement was extensively used for sensitive determination of compounds exhibited unique fluorescence features.

OBJECTIVE

The main objective of this work was to develop higher sensitive cost effective spectrofluorometric method for selective determination of ritonavir in the presence of nirmatrelvir in pure form, pharmaceutical tablet as well as in spiked human plasma.

METHODS

Ritonavir was found to exhibit unique native emission fluorescence at 404 nm when excited at 326 nm. On the other hand, nirmatrelvir had no emission bands when excited at 326 nm. This feature allowed selective determination of ritonavir without any interference from nirmatrelvir. The variables affecting fluorescence intensity of ritonavir were optimized in terms of sensitivity parameters and principles of green analytical chemistry. Ethanol was used a green solvent which provided efficient fluorescence intensity of the cited drug.

RESULTS

The method was validated in accordance with the ICH Q2 (R1) standards in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and specificity. The described method was successfully applied for ritonavir assay over the concentration range of 2.0-20.0 ng/mL.

CONCLUSION

Ritonavir determination in the spiked human plasma was successfully done with satisfactory accepted results.

Adjusted green spectrophotometric determination of favipiravir and remdesivir in pharmaceutical form and spiked human plasma sample using different chemometric supported models

The environmentally friendly design of analytical methods is gaining interest in pharmaceutical analysis to reduce hazardous environmental impacts and improve safety and health conditions for analysts. The adaptation and integration of chemometrics in the development of environmentally friendly analytical methods is strongly recommended in the hope of promising benefits. Favipiravir and remdesivir have been included in the COVID-19 treatment guidelines panel of several countries. The main objective of this work is to develop green, tuned spectrophotometric methods based on chemometric based models for the determination of favipiravir and remdesivir in spiked human plasma. The UV absorption spectra of favipiravir and remdesivir has shown overlap to some extent, making simultaneous determination difficult. Three advanced chemometric models, classical least squares, principal component regression, and partial least squares, have been developed to provide resolution and spectrophotometric determination of the drugs under study. A five-level, two-factor experimental design has been used to create the described models. The spectrally recorded data of favipiravir and remdesivir has been reviewed. The noise region has been neglected as it has a negative impact on the significant data. On the other hand, the other spectral data provided relevant information about the investigated drugs. A comprehensive evaluation and interpretation of the results of the described models and a statistical comparison with accepted values have been considered. The proposed models have been successfully applied to the spectrophotometric determination of favipiravir and remdesivir in pharmaceutical form spiked human plasma. In addition, the environmental friendliness of the described models was evaluated using the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The results showed the compliance of the described models with the environmental characteristics.

Green-adapted spectrophotometric determination of fostemsavir based on selective bromophenol blue extraction; reduction of hazardous consumption using computational calculations

A computationally-assisted and green spectrophotometric method has been developed for the determination of fostemsavir, a recently FDA-approved drug used in combination with antiretroviral drugs to treat multidrug-resistant HIV-1 infection. The method was developed using computational studies and solvent selection based on green chemistry principles. The density functional theory method was employed to identify bromophenol blue as the preferred acid dye for efficient extraction of fostemsavir. The solvent selection process involved a careful evaluation of the green ranking of solvents, which led to the use of water as the solvent. The method involved the extraction of fostemsavir with bromophenol blue to form a yellow ion-pair complex, which exhibited maximally sharp peaks at 418 nm, enabling sensitive visible spectrophotometric determination of fostemsavir in bulk and pharmaceutical preparations. The extraction procedures were optimized, and the method was demonstrated to be sensitive over the concentration range of 2-12 μg/mL fostemsavir. Furthermore, the method was evaluated with respect to green chemistry principles using the analytical eco-scale, the green analytical method index, and analytical greenness metric approach, all of which confirmed that the data obtained by the proposed method were environmentally acceptable.

Quantitative analysis of two COVID-19 antiviral agents, favipiravir and remdesivir, in spiked human plasma using spectrophotometric methods; greenness evaluation

Favipiravir and remdesivir have been included in the COVID-19 treatment guidelines panel of several countries. The main objective of the current work is to develop the first validated green spectrophotometric methods for the determination of favipiravir and remdesivir in spiked human plasma. The UV absorption spectra of favipiravir and remdesivir have shown some overlap, making simultaneous determination difficult. Due to the considerable overlap, two ratio spectra manipulating spectrophotometric methods, namely, ratio difference and the first derivative of ratio spectra, enabled the determination of favipiravir and remdesivir in their pure forms and spiked plasma. The ratio spectra of favipiravir and remdesivir were derived by dividing the spectra of each drug by the suitable spectrum of another drug as a divisor to get the ratio spectra. Favipiravir was determined by calculating the difference between 222 and 256 nm of the derived ratio spectra, while calculating the difference between 247 and 271 nm of the derived ratio spectra enabled the determination of remdesivir. Moreover, the ratio spectra of every drug were transformed to the first order derivative using ∆λ = 4 and a scaling factor of 100. The first-order derivative amplitude values at 228 and 251.20 nm enabled the determination of favipiravir and remdesivir, respectively. Regarding the pharmacokinetic profile of favipiravir (C_max 4.43 µg/mL) and remdesivir (C_max 3027 ng/mL), the proposed methods have been successfully applied to the spectrophotometric determination of favipiravir and remdesivir in plasma matrix. Additionally, the greenness of the described methods was evaluated using three metrics systems: the national environmental method index, the analytical eco-scale, and the analytical greenness metric. The results demonstrated that the described models were in accordance with the environmental characteristics.

Synchronous spectrofluorimetric determination of favipiravir and aspirin at the nano-gram scale in spiked human plasma; greenness evaluation

Favipiravir and aspirin are co-administered during COVID-19 treatment to prevent venous thromboembolism. For the first time, a spectrofluorometric method has been developed for the simultaneous analysis of favipiravir and aspirin in plasma matrix at nano-gram detection limits. The native fluorescence spectra of favipiravir and aspirin in ethanol showed overlapping emission spectra at 423 nm and 403 nm, respectively, after excitation at 368 nm and 298 nm, respectively. Direct simultaneous determination with normal fluorescence spectroscopy was difficult. The use of synchronous fluorescence spectroscopy for analyzing the studied drugs in ethanol at Δλ = 80 nm improved spectral resolution and enabled the determination of favipiravir and aspirin in the plasma matrix at 437 nm and 384 nm, respectively. The method described allowed sensitive determination of favipiravir and aspirin over a concentration range of 10-500 ng/mL and 35-1600 ng/mL, respectively. The described method was validated with respect to the ICH M10 guidelines and successfully applied for the simultaneous determination of the mentioned drugs in pure form and in the spiked plasma matrix. Moreover, the compliance of the method with the concepts of environmentally friendly analytical chemistry was evaluated using two metrics, the Green Analytical Procedure Index and the AGREE tool. The results showed that the described method was consistent with the accepted metrics for green analytical chemistry.

Green fitted second derivative synchronous spectrofluorometric method for simultaneous determination of remdesivir and apixaban at Nano gram scale in the spiked human plasma

Remdesivir and apixaban have been included in the treatment guidelines of several countries for severe COVID-19 infections. To date, no analytical method has been developed for the determination of remdesivir and apixaban in plasma matrix. The main objective of this work was to develop a highly sensitive, green-adapted spectrofluorometric method for the determination of remdesivir and apixaban at the Nanoscale. Remdesivir and apixaban showed overlapping fluorescence emission spectra at 403 nm and 456 nm when excited at 246 nm and 285 nm, respectively. This overlap was resolved in two steps. The first step was synchronous fluorescence scanning of remdesivir and apixaban, and the second step was manipulation of the second-order derivative for the obtained spectra. These steps allowed complete resolution of the overlapping fluorescence spectra and selective determination of remdesivir and apixaban at 410 and 469 nm, respectively. The variables affecting the synchronous scanning of the aforementioned drugs were optimized in terms of sensitivity parameters and principles of green analytical chemistry. The described method allowed sensitive determination of remdesivir and apixaban over the concentration range of 5-200 ng/mL and 50-3000 ng/mL, respectively. The described method was validated and successfully applied for the simultaneous determination of the mentioned drugs in pure form and in spiked human plasma.