Preliminary stability studies on analytical solutions in a pharmaceutical laboratory

Abstract

Accuracy and reliability of the analytical results is crucial for ensuring quality, safety and efficacy of pharmaceutical products. Consequently, method validation is a vital aspect for the efficient and reliable application of analytical procedures. The robustness of three reversed-phase HPLC assay procedures was tested with respect to the stability of analytical solutions. Stability testing of the pharmaceutical compounds in solution was carried out by monitoring the change in the content of the active substance over time. The concentration of active was determined chromatographically, by analysing the test solutions against freshly prepared standard solutions. The stability of the pharmaceutical compounds in solution was monitored under three conditions. No apparent degradation of ramipril was identified over the time interval for which analytical solutions of the pharmaceutical compound were tested. Terbinafine hydrochloride was found to undergo degradation in solution. Further studies into the stability of analytical solutions of amlodipne besilate would be required to determine if the compound undergoes degradation when present in solution. The evaporation of solvent from analytical solutions was found to have a significant effect on the robustness of the analytical procedures when the time between solution preparation and analysis is extended. The specificity of the chromatographic procedure for the determination of ramipril was challenged by forced degradation studies. The procedure was proved to be specific and stability indicating, that is capable of assessing the analyte in the presence of its degradation products. The intermediate precisions, calculated from stability data, were found to be in the range of 0.46 - 1.12%. The intermediate precision values associated with assay procedures for the determination of the active substance in the finished product, were higher than those associated with the assay procedure for the determination of the active in the drug substance.