Mutations in SARS-CoV-2: Insights on structure, variants, vaccines, and biomedical interventions.

COVID-19 is a worldwide pandemic caused by SARS-coronavirus-2 (SARS-CoV-2). Less than a year after the emergence of the Covid-19 pandemic, many vaccines have arrived on the market with innovative technologies in the field of vaccinology. Based on the use of messenger RNA (mRNA) encoding the Spike SARS-Cov-2 protein or on the use of recombinant adenovirus vectors enabling the gene encoding the Spike protein to be introduced into our cells, these strategies make it possible to envisage the vaccination in a new light with tools that are more scalable than the vaccine strategies used so far. Faced with the appearance of new variants, which will gradually take precedence over the strain at the origin of the pandemic, these new strategies will allow a much faster update of vaccines to fight against these new variants, some of which may escape neutralization by vaccine antibodies. However, only a vaccination policy based on rapid and massive vaccination of the population but requiring a supply of sufficient doses could make it possible to combat the emergence of these variants. Indeed, the greater the number of infected individuals, the faster the virus multiplies, with an increased risk of the emergence of variants in these RNA viruses. This review will discuss SARS-CoV-2 pathophysiology and evolution approaches in altered transmission platforms and emphasize the different mutations and how they influence the virus characteristics. Also, this article summarizes the common vaccines and the implication of the mutations and genetic variety of SARS-CoV-2 on the COVID-19 biomedical arbitrations.

The Development of Eletriptan Hydrobromide Immediate Release Buccal Films Using Central Composite Rotatable Design: An In Vivo and In Vitro Approach.

The objective is to develop immediate release buccal films of Eletriptan Hydrobromide (EHBR) using hydroxypropyl methylcellulose (HPMC) E5. The buccal films have the ability to disintegrate rapidly and provide both systemic and local effects. The solvent casting method was employed to prepare the films and the central composite rotatable design (CCRD) model was used for film optimization. All the formulated films were characterized for physicochemical evaluation (Fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), differential scanning calorimetry (DSC), and Scanning electron microscopy (SEM), in in-vitro, ex-vivo, and in-vivo drug release. The fabricated films were transparent, colorless, and evenly distributed. The FTIR spectra showed no chemical interaction between the drug and excipients. In in-vitro analysis, the film has the highest% drug release (102.61 ± 1.13), while a maximum of 92.87 ± 0.87% drug was diffused across the cellulose membrane having a pore size of 0.45 µm. In the ex-vivo study, drug diffusion across the goat mucosa was performed and 80.9% of the drug was released in 30 min. In-vivo results depict a mean half-life (t½) of 4.54 ± 0.18 h and a Cmax of 128 ± 0.87 (ng/mL); Tmax was achieved in 1 h. Furthermore, instability and histopathological studies buccal films were proven to be safe and act as an effective dosage form. In a nutshell, optimized and safe instant release EHBR buccal films were prepared that have the tendency to provide effect effectively.

Development and validation of sensitive kinetic spectrophotometric method for the determination of moxifloxacin antibiotic in pure and commercial tablets.

New, accurate, sensitive and reliable kinetic spectrophotometric method for the assay of moxifloxacin hydrochloride (MOXF) in pure form and pharmaceutical formulations has been developed. The method involves the oxidative coupling reaction of MOXF with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) in the presence of Ce(IV) in an acidic medium to form colored product with lambda max at 623 and 660 nm. The reaction is followed spectrophotometrically by measuring the increase in absorbance at 623 nm as a function of time. The initial rate and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1.89-40.0 µg mL(-1) for initial rate and fixed time methods. The limit of detection for initial rate and fixed time methods is 0.644 and 0.043 µg mL(-1), respectively. Molar absorptivity for the method was found to be 0.89×10(4) L mol(-1) cm(-1). Statistical treatment of the experimental results indicates that the methods are precise and accurate. The proposed method has been applied successfully for the estimation of moxifloxacin hydrochloride in tablet dosage form with no interference from the excipients. The results are compared with the official method.

Novel spectrophotometric method for determination of some macrolide antibiotics in pharmaceutical formulations using 1,2-naphthoquinone-4-sulphonate.

New, simple and rapid spectrophotometric method has been developed and validated for the assay of two macrolide drugs, azithromycin (AZT) and erythromycin (ERY) in pure and pharmaceutical formulations. The proposed method was based on the reaction of AZT and ERY with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline medium at 25 °C to form an orange-colored product of maximum absorption peak at 452 nm. All variables were studied to optimize the reaction conditions and the reaction mechanism was postulated. Beer's law was obeyed in the concentration range 1.5-33.0 and 0.92-8.0 µg mL(-1) with limit of detection values of 0.026 and 0.063 µg mL(-1) for AZT and ERY, respectively. The calculated molar absorptivity values are 4.3 × 10(4) and 12.3 × 10(4) L mol(-1) cm(-1) for AZT and ERY, respectively. The proposed methods were successfully applied to the determination of AZT and ERY in formulations and the results tallied well with the label claim. The results were statistically compared with those of an official method by applying the Student's t-test and F-test. No interference was observed from the concomitant substances normally added to preparations.

Spectrophotometric Determination of Alfuzosin HCl in Pharmaceutical Formulations with some Sulphonephthalein Dyes.

Bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) were used to determine alfuzosin hydrochloride either in pure form or in pharmaceutical formulations. Alfuzosin was extracted as an ion-pair complex from sample solution containing KCl-HCl buffer pH2.2, 2.4 and 2.6 into CHCl3 and the absorbance was measured at 407, 413 and 412nm with use of the cited reagents, respectively. The analytical parameters and their effects on the reported systems are investigated. The reactions were extremely rapid at room temperature and the absorbance values remains unchanged up to 24 h. Beer's law was obeyed in the concentration ranges 1.20-38.3, 0.85-46.0 and 0.63-34.0 µg/ml and detection limits were 0.28, 0.24 and 0.18 µg/ml with BCP, BPB and BTB, respectively. Recoveries were 98.80-101.33%. Interferences of the other ingredients and excipients were not observed. The proposed method is simple, fast and sensitive, and the first reported extractive method for the determination of alfuzosin in commercial tablets.