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.