Influence of active pharmaceutical ingredient structures on Hansen solubility parameters

Abstract

In drug development, preformulation is the key step, where compatibility between active pharmaceutical ingredient (API) and excipients is the crucial parameter. To simplify this process, reliable and suitable prediction models are needed. In this case, Hansen solubility parameters (HSPs) can be used. Moreover, HSPs can also describe and characterize the surface properties of the measured substances. Precisely, the surface properties of APIs and excipients affect the compatibility of the resulting dosage form. In this work, HSPs of six selected APIs of different chemical nature were determined (tadalafil, vardenafil-hydrochloride trihydrate, mefenamic acid, bisoprolol hemi-fumarate, meloxicam and indomethacin) using inverse gas chromatography (IGC) according to Snyder and Karger adsorption model. This study aimed to investigate the influence of APIs structure on HSPs and to prove the sensitivity of this method to different chemical nature of measured substances. Our results showed the influence of selected APIs chemical nature on HSPs. These results can provide a better understanding of API behaviour during the drug development process.

Keywords: Compatibility; Energy of adsorption; Hansen solubility parameters; Inverse gas chromatography; Snyder and Karger adsorption model; van Krevelen.