Application of different quantitative analytical techniques for estimation of aspirin and omeprazole in pharmaceutical preparation

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.

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.

Green adherent spectrophotometric determination of molnupiravir based on computational calculations; application to a recently FDA-approved pharmaceutical dosage form

Molnupiravir is an oral antiviral drug developed to provide significant benefit in reducing hospitalizations or deaths in mild COVID-19. Integrated green computational spectrophotometric method was developed for the determination of molnupiravir. Theoretical calculations were performed to predict the best coupling agent for efficient diazo coupling of molnupiravir. The binding energy between molnupiravir and various phenolic coupling agents, α-naphthol, β-naphthol, 8-hydroxyquinoline, resorcinol, and phloroglucinol, was measured using Gaussian 03 software based on the density functional theory method and the basis set B3LYP/6-31G(d). The results showed that the interaction between molnupiravir and 8-hydroxyquinoline was higher than that of other phenolic coupling agents. The method described was based on the formation of a red colored chromogen by the diazo coupling of molnupiravir with sodium nitrite in acidic medium to form a diazonium ion coupled with 8-hydroxyquinoline. The absorption spectra showed maximum sharp peaks at 515 nm. The reaction conditions were optimized. Beer's law was followed over the concentration range of 1-12 μg/ml molnupiravir. Job's continuous variation method was developed and the stoichiometric ratio of molnupiravir to 8-hydroxyquinoline was determined to be 1:1. The described method was successfully applied to the determination of molnupiravir in pure form and in pharmaceutical dosage form. The results showed that the proposed method has minimal environmental impact compared to previous HPLC method.

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

Lesinurad and allopurinol have been formulated in a combined dosage form providing a new challenge for the treatment of gout attacks. Two mathematical based spectrophotometric methods, area under the curve, and artificial neural networks have been developed for simultaneous determination of lesinurad and allopurinol in pure form and in combined pharmaceutical dosage form. Area under the curve has been utilized to resolve the spectral overlap between lesinurad and allopurinol. Values of area under the curve and area absorptivity were measured at two selected wavelength ranges of 242-250 nm and 255-265 nm. Two mathematically constructed equations have been used to determine the concentrations of the drugs under the study. Advanced chemometry based model, artificial neural network, has been developed utilizing the UV spectral data of lesinurad and allopurinol through various defined steps. A five-level, two-factor experimental design was used to construct 25 mixtures. Thirteen mixtures were used to set up the calibration model and 12 mixtures were used to construct a validation set. The artificial neural network model was optimized to enable precise spectrophotometric determination of the drugs under the study. The described mathematically bases spectrophotometric methods have been successfully applied to the determination of lesinurad and allopurinol in the new combined, Duzallo® tablets. Furthermore, the greenness of the described methods was assessed using four different tools namely, the national environmental method index, the analytical eco-scale, the green analytical procedure index and the AGREE evaluation method. The proposed methods showed more adherence to the greenness characters in comparison to the previously reported HPLC method.

Evaluation of Medicine Information Leaflets for Omeprazole, Safety Knowledge, and Perceptions of Taking the Medication in Thailand

PURPOSE

This study aimed to compare package inserts and patient information leaflets for omeprazole in terms of the quality of and satisfaction with the written medicine information, medication safety knowledge, and perceived benefits and risks.

PATIENTS AND METHODS

A cross-sectional, comparative study was conducted at a university hospital in Thailand. Outpatients visiting the pharmacy departments prescribed omeprazole were randomly selected to receive either a package insert or a patient information leaflet. Medication safety knowledge was measured using a set of eight questions. The quality of the written medicine information was measured by the Consumer Information Rating Form. Perceived benefits and risks of the medication were rated using a visual analog scale. Linear regression was used to determine factors associated with perceived benefits and risks.

RESULTS

Of the 645 patients, 293 agreed to answer the questionnaire. 157 and 136 patients were given patient information leaflets and package inserts, respectively. Most respondents were female (65.6%), over half had a degree (56.2%). Patients reading the patient information leaflets had slightly higher overall safety knowledge scores than those reading the package inserts (5.88 ± 2.25 vs 5.25 ± 1.84, p=0.01). Using the Consumer Information Rating Form, the patient information leaflets were given significantly higher scores compared to the package inserts for comprehensibility (19.34±3.92 vs 17.32±3.52, p<0.001) and design quality (29.25 ± 5.00 vs 23.81 ± 5.16, p<0.001). After reading the leaflets, patients receiving the patient information leaflets had significantly higher satisfaction with the information provided (p=0.003). In contrast, those receiving the package inserts rated the risks of omeprazole higher (p=0.007).

CONCLUSION

Demonstrable differences were found from the patient perspective between a package insert and a patient information leaflet for the same medicine, mostly in favour of patient information leaflets. Medicine safety knowledge after reading PI and PIL was similar. However, receiving package inserts provided higher perceived risks from taking the medicine.