Simultaneous controlled vitamin release from multiparticulates: theory and experiment.

The aim of this study was to simultaneously control the release of multiple vitamins exhibiting very different water-solubility and molecular weights from multiparticulates. Several types of sucrose esters and triglycerides were studied as matrix formers in granules prepared by wet granulation, melt granulation or compression and grinding. The vitamin release kinetics were measured in 0.1N HCl, phosphate buffer pH 6.8 and water in a USP paddle apparatus. An appropriate analytical solution of Fick's second law of diffusion was used to better understand the underlying mass transport phenomena. Importantly, the release rates of nicotinamide, pyridoxine hydrochloride, riboflavin 5'-phosphate, riboflavin, thiamine chloride hydrochloride and thiamine nitrate can simultaneously be controlled from the investigated multiparticulates. Varying the total vitamin content, granule size, type of preparation technique and type of matrix former (Sucrose Stearate S370, Sucrose Stearate S1170, glycerol dibehenate, glycerol dipalmitostearate), desired vitamin release rates can be adjusted. Interestingly, diffusion seems to be the dominant mass transport mechanism in most cases. Thus, appropriate solutions of Fick's law can be used to quantitatively predict the effects of the systems' composition and dimensions on the resulting vitamin release patterns. This knowledge can significantly help facilitating device optimization.