Comparative taste-masking evaluation of microencapsulated bitter drugs using Smartseal 30D and ReadyMix for paediatric dosage forms.

The taste of drug substances plays a key role in the development of paediatric formulations with suitable organoleptic properties. The aim of the study was to evaluate the taste masking effectiveness of Smartseal 30D and ReadyMix on a range of bitter drug substances such as diphenhydramine HCl (DPD), ibuprofen lysine (IBU-LS), and phenylephrine HCl (PPH) for the development of paediatric dosage forms. The drugs were microencapsulated in the polymer carriers at 10-20% loadings using spray-drying processing. Spray drying of drug formulations was optimized in terms of percent yield and encapsulation efficiency followed by physicochemical characterization in order to identify the drugs' physical state in the polymer microparticles. The in vivo taste masking efficiency was evaluated using human test panel and showed noticeable reduction of drug's bitterness at all loadings in comparison to the bulk substances.

An investigation into the formations of the internal microstructures of solid dispersions prepared by hot melt extrusion.

Hot melt extrusion (HME) is a widely used manufacturing process for pharmaceutical solid dispersions. The complexity of the HME formulations and the number of excipients used in the process are increasing with the advancement of the relevant knowledge. However, one of the areas that is still significantly lacking understanding is the control of internal microstructure of extrudates. Internal microstructure, consisting of voids, in hot melt extruded amorphous solid dispersions is often observed without the causes having been systemically investigated in the literature. In this study, we investigated a range of factors that demonstrated their impacts on the formation of the voids. These include the effect of the types of the materials (i.e. drug, polymer and additive) used in the formulation, the quantity of the drug and the additives used, the key extrusion processing parameters, the type of extruder, and the drying of the raw materials prior to extrusion. The results indicate that the appropriate viscosity and the presence of phase-separated particulates are essential for the formation of the voids. The particulates act as nuclei for the entrapped gas bubbles and the viscosity of the mixture during extrusion governs the collapse/escape of the bubbles. To minimise void formation, the results of this study indicate that slow screw speed, low moisture content of the raw materials, fewer particulates and the addition of lubricants, such as low melting lipid excipients, could be beneficial. This study systematically examines the mechanism of void formation in HME extrudates and generates new strategies that can be used to manage such void formations.