Degradation kinetics study of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) by a validated stability-indicating RP-HPLC method

Abstract

The chemical stability of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (FLAG), a therapeutic agent for neutropenia, was investigated using a validated stability-indicating reversed phase high-performance liquid chromatographic (RP-HPLC) method. The forced degradation of PLAG was carried out under the stress conditions of hydrolysis (alkaline, acidic and various pH buffers), oxidation, photolysis and heat. A simple, sensitive, specific, robust, precise and accurate RP-HPLC method was developed and validated for evaluating the degradation kinetics of FLAG. The chromatographic validation of various parameters, such as system suitability, detection limit, quantification limit, linearity, accuracy, precision, specificity, robustness and stability, was achieved. The method was validated for linearity, accuracy and precision over the concentration range of 0.7813-100 mu g/mL(r(2) = 0.9999). The proposed method provided excellent stability study of FLAG indicated by the resolution of degradation products from the drug. Degradation of FLAG provided first order kinetics under all experimental conditions. PLAG was catalysed more rapidly in alkaline and acidic conditions than in neutral conditions. PLAG was relatively stable in photolytic and oxidative conditions compared to hydrolysis and thermal conditions, although this drug was not also stable in these conditions. Exposed to high temperature, FLAG was more rapidly catalysed. The activation energy evaluated from the Arrhenius plot was about 110 kJ/mol in the thermal conditions. Additionally, FLAG with a t(1/2) of about 400 h was very stable at room temperature. Therefore, FLAG was considerably influenced by alkaline and acidic hydrolysis, and thermal degradation.