Green chemistry approach: method development and validation for identification and quantification of entecavir using FT-IR in bulk and pharmaceutical dosage form

Background

Chemical hazard is one of the most prominent side effects that come out along with the benefits of pharmaceutical production. Chemicals usage and waste production are involved in each step of production and are found to be in high percentage at the stage of quality testing. Conventional quality testing (assay) involves the use of solvents and reagents that generates high flammable and non-flammable waste and also enhanced the per batch cost of the medicine, whereas green chemistry offers a benign environment for drug designing, manufacturing, and analysis.

Results

In the present study, a green FTIR method for assay of antiviral drugs entecavir is developed and validated as per ICH Q2_R1 guidelines. A calibration curve is plotted between absorbance and concentration, yielding excellent linearity with a correlation coefficient (r2) value of 0.9991 in the concentration range of 0.25–0.75 mg.

Conclusion

The developed method was validated and was very specific, accurate (99.9–100%) at three levels of 80, 100, and 120% of test concentration and precise with < 1% RSD. The LOD of the method is 0.0674 mg and is able to quantify the active at the limit of 0.2042 mg. Four different drug brands available in the local market are assayed by the validated method, and %recoveries are found to be in the range of 99–101%.

Graphical abstract

Green Chemistry Approach: Method Development and Validation for Identification and Quantification of Entecavir using FT-IR in Bulk and Pharmaceutical Dosage Form

LC-ESI-MS/MS method for the quantification of entecavir in human plasma and its application to bioequivalence study

Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used for a quantitative estimation of entecavir (EV) in human plasma using lamivudine (LM) as internal standard (IS). The method herein described is simple, sensitive, and specific. Chromatographic separation was performed on XBridge-C18, 4.6 mm × 50 mm, 5-μm column with an isocratic mobile phase composed of 10 mM ammonium hydrogen carbonate (pH 10.5):methanol (85:15 v/v), pumped at 0.3 ml/min. EV and LM were detected using proton adducts at m/z 278.1→152.1 and 230.2→112.0 in multiple reaction monitoring (MRM) positive mode. Solid phase extraction method was employed in the extraction of EV and LM from the biological matrix. This method was validated over a linear concentration range of 50.0-20000.0 pg/ml with a correlation coefficient (r) ≥0.9983. Intra and inter-day precision of EV was found within the range of 1.2-4.2 for EV and 4.4-4.5 for LM. EV was stable throughout three freeze/thaw cycles, bench top and postoperative studies. This method was successfully used in the analysis of plasma samples following oral administration of EV (0.5 mg) in 26 healthy human volunteers.