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.

Taste masking of paracetamol by hot-melt extrusion: an in vitro and in vivo evaluation.

The purpose of this study was the in vitro and in vivo evaluation of the masking efficiency of hot melt extruded paracetamol (PMOL) formulations. Extruded granules containing high PMOL loadings in Eudragit EPO (EPO) or Kollidon VA64 (VA64) were prepared by hot-melt extrusion (HME). The taste masking effect of the processed formulation was evaluated in vivo by a panel of six healthy human volunteers.

Palladium-Catalyzed 1,4-Acetoxy-Trifluoroacetoxylation and 1,4-Alkoxy-Trifluoroacetoxylation of Cyclic 1,3-Dienes. Scope and Mechanism.

Palladium-catalyzed unsymmetrical 1,4-functionalizations of cyclic 1,3-dienes are described. Trifluoroacetate in combination with acetate or alcohols is utilized to obtain 1-acetoxy-4-(trifluoroacetoxy)-2-cycloalkenes and 1-alkoxy-4-(trifluoroacetoxy)-2-cycloalkenes, respectively, with good regio- and stereoselectivities. The chemoselectivity of these reactions relies on the different kinetic stability of the intermediate 4-(trifluoroacetoxy)-, 4-acetoxy-, and 4-methoxy-[eta(3)-(1,2,3)-cycloalkenyl]palladium complexes.

Syntheses of Theaspirone and Vitispirane via Palladium(II)-Catalyzed Oxaspirocyclization.

Total syntheses of theaspirone (A and B) and vitispirane (A and B) are described. The key step in the syntheses is the palladium(II)-catalyzed intramolecular oxaspirocyclization of diene alcohol 4 to either vitispirane or the allylic alcohol 9. The outcome of the oxaspirocyclization is very much dependent on the solvent employed.