An in-vivo and in-vitro taste masking evaluation of bitter melt-extruded drugs

Objectives The purpose of this study was to investigate the potential of hot-melt extrusion (HME) for masking the taste of bitter active pharmaceutical ingredients (APIs) when incorporated into different polymer formulations. Methods Extrudates were produced by HME using two water soluble cationic model drugs (cetirizine HCl and verapamil HCl) processed with various grades of anionic polymers (Eudragit L100 and Eudragit L100-55 (Acryl EZE)). The process was optimised by using a single screw extruder to produce extruadates with the desirable characteristics. Key findings In-vivo results obtained from a panel of six healthy human volunteers demonstrated that the HME extruded formulations improved the taste significantly compared with that of the pure APIs. In addition, an in-vitro evaluation carried out by an Astree e-tongue equipped with seven specific sensors demonstrated significant taste improvement of the extrudates compared with placebo polymers and the pure APIs. Furthermore, the extrudates characterised by SEM, X-ray and differential scanning calorimetry studies showed the existence of molecularly dispersed APIs while in-vitro dissolution showed fast release for all drug substances. Conclusions HME can effectively be used to mask the taste of bitter APIs by enhancing drug–polymer interactions.