Preparo de micropartículas lipídicas de cera de carnaúba como estratégia tecnológica visando o mascaramento de sabor desagradável de fármacos hidrossolúveis

Abstract

The bitter taste present in many drugs can compromise therapeutic adherence, especially among children and the elderly, as the unpleasant flavor can make medication administration more difficult. Therefore, taste masking becomes a viable strategy to improve treatment adherence and acceptance, and consequently, the quality of the pharmaceutical product. In this context, the present study aimed to develop microparticulate systems as a lipid-based platform for masking the unpleasant taste of water-soluble drugs. Carnauba wax was used as the lipid excipient, and the frozen emulsion method was employed as the taste-masking technique. The method was based on the preparation of two immiscible phases: a lipid phase, composed of carnauba wax and dipyrone, and an aqueous phase, consisting of Milli-Q water and the surfactant Tween 80. The aqueous phase was heated to 90 °C on a heating plate under stirring with a mechanical agitator, and once this temperature was reached, the lipid phase was melted on a separate heating plate. Subsequently, the lipid phase was poured into the aqueous phase under stirring. Two different homogenization methods were tested during this step: (i) using an Ultra-Turrax operating at 10,000 rpm for 1 minute, and (ii) a mechanical agitator A-20 operating at 3,500 rpm for 1 minute. After homogenization, cold water was added to the dispersion, which was stirred again for 1 minute. Finally, the mixture was kept under magnetic stirring for an additional 15 minutes. The microparticles obtained were characterized in terms of morphology, using stereomicroscopy and optical microscopy, and in terms of particle size distribution, using a sieve shaker. The microparticles produced with the Ultra-Turrax showed predominantly spherical morphology but exhibited a widely divergent bimodal size distribution, with higher concentrations retained in the 600 μm and 45 μm sieves. In contrast, the microparticles obtained using the A-20 mechanical agitator displayed less spherical morphology, but a more consistent bimodal size distribution, with concentrations in the 150 μm and 45 μm sieves. Thus, although carnauba wax and the frozen emulsion method proved effective in forming microparticulate systems, further testing is necessary to improve the uniformity and sphericity of the microparticles.