Kinetic study and peak purity determination of bupropion hydrochloride using RRLC/DAD and HPLC/MWD methods: stability study and application in pharmaceutical preparation and in synthetic mixtures with nicotine

Abstract

Two validated stability indicating chromatographic methods have been developed and used for the kinetic study and determination of bupropion HCl in presence of its degradation products and nicotine.

Validated Stability-Indicating UPLC Method for Determination of Dapoxetine and Fluoxetine: Characterization of Their Hydrolytic Degradation Products, Kinetic Study and Application in Pharmaceutical Dosage Forms

“…Figure 8a and 8b show that increasing the temperature leading to increasing of the reaction rate constant. From the slopes of the regression lines, it was possible to calculate the apparent first order degradation rate constants (K obs) and the halflife at each temperature was calculated in according to the following equations [31]: Log (C t / C o ) +2= -K obs t, t½ = 0.693/ K obs , K obs = -2.303 slope Where C t = concentration remaining at time t, C o = initial concentration, K obs = apparent rate constant, t ½ is the half-life.…”

“…The activation energy was calculated by applying the following equations [31]: Log K obs = log A-Ea 2.303 RT Slope = -Ea/ 2.303 R Where: K is the reaction rate constant, A is the frequency factor, Ea is the activation energy, R is the universal gas constant, T is the absolute temperature in Kelvin.…”