Formulation of paracetamol-containing pastilles with in situ coating technology

The focus of this research was to apply the in situ coating technology for producing paracetamol- (PCT-) containing pastilles for paediatric use from a eutectic of two sugar alcohols (sorbitol, xylitol) in one step. This type of melt-technology is more cost-efficient and simpler than other conventional tableting technologies, whereby the formation of the pastilles and their coating occur upon the same fabrication step. We managed to produce pastilles having a softer core and a harder, resistant shell in one cooling step. Adding polyethylene glycol (PEG) 2000 or 6000 to the PCT-containing eutectic, the dissolution rate of PCT could be considerably increased, especially when using PEG 2000, reaching equal dissolution characteristics both under mouth- and gastric-specific conditions. Distributions of the components within the pastilles have been determined by X-ray scattering and Raman spectroscopy. Physico-chemical parameters of the xylitol-sorbitol eutectic and their changes upon adding PCT and PEGs have been determined, and it has been revealed that xylitol and sorbitol form a new entity with a distinguished crystal structure. The significant changes in viscosity were explained and the interaction in the eutectic mixture was investigated using Fourier transform infrared spectroscopy (FT-IR). The uniformity of the physical parameters of the pastilles (including size, weight and drug content) also demonstrates the feasibility of using the cost-efficient and simple one-step eutectic-cooling technology for manufacturing pastilles.