Thermogravimetric analysis and decomposition kinetics of velpatasvir co-povidone under non-isothermal conditions

EL-Shorbagy, Hanan Ibrahim; Mohamed, Mona; El-Gendy, Alaa; Belal, Fathalla; Hadad, Ghada

doi:10.21608/rpbs.2023.166748.1177

Thermogravimetric analysis and decomposition kinetics of velpatasvir co-povidone under non-isothermal conditions

Document Type : Original Article

Authors

¹ Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt

² Pharmaceutical Chemistry Department, National Organization for Drug Control and Research (NODCAR), Giza, Egypt

³ Faculty of Pharmacy - Suez Canal University

⁴ Faculty of Pharmacy -Mansora University

⁵ Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt

10.21608/rpbs.2023.166748.1177

Abstract

The thermal decomposition of velpatasvir:copovidone (1:1) was studied by simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG). The influence of the heating rate (10 oC min-1) on the TG was verified. For the determination of kinetic parameters from the TG/DTG curves, the following methods were utilized: Arrhenius equation, Horwitz–Metzger, and Coats–Redfern methods. The kinetic studies of velpatasvir copovidone showed a thermal behavior characteristic of first order according to the activation energy. The activation energy obtained was found to be about 99.93±9.09 kJ mol-1. The TGA/DTG curves demonstrate that the drug undergoes two phases of thermal decomposition. The first is due to the dehydration of copovidone. The second phase occurs at three thermal decomposition steps. The first thermal decomposition step occurred at an interval of 210.0–407.0 oC. The second thermal decomposition step occurs in the interval of 407.0–465.0 oC. The third thermal decomposition step occurs in the interval of 465.0–621.0 oC, which may be attributed to the complete thermal decomposition.

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