Response surface analysis applied to the preparation of tablets containing a high concentration of vegetable spray-dried extract.

This work relates to the formulation of tablets containing a high proportion of spray-dried extracts (SDEs) from Passiflora edulis leaves. The tablets were prepared by direct compression. Colloidal silicon dioxide was selected as a glidant and moisture adsorbent, cross-linked carboxymethycellulose was used as the disintegrant, microcrystalline cellulose was the filler/binder, and tricalcium phosphate as a spray-drying adjuvant. The colloidal silicon dioxide and cross-linked carboxymethycellulose quantities and their influences on the tablet hardness and disintegration time were studied by a central composite design. The model equations were fitted to the experimental data and then validated. It could be concluded that the colloidal silicon dioxide proportion increased the hardness, and the cross-linked carboxymethycellulose proportion determined a linear decrease of the disintegration time. The optimal values chosen were 2.0% Aerosil 200 and 2.5% Ac-Di-Sol. The tablets showed a hardness of 85.02 N and a disintegration time of 7.35 min.