The statistical analysis of the percentage of drug dissolved from different formulations showed a significant influence of the lubricant on this parameter (p ≤ 0.05). The influence of the filler-binder granulometry was dependent on the level of lubricant. Magnesium stearate showed a negative influence on the dissolution of ASA from tablets prepared both with Avicel- PH 101 and Avicel-PH 102 (21.59 ± 3.81 % and 16.31 ± 4.70%, respectively) compared to those formulations prepared with stearic acid (33.69 ± 6.30% and 49.35 ± 19.98, respectively). Magne- sium stearate is a hydrophobic material and hence has a negative effect on drug release from formulations 7,12,20,21. In relation to the filler-binder granulometry, the formulation lubri- cated by stearic acid and prepared with Avicel- PH 101 instead of Avicel-PH 102 demonstrated a higher drug release after 30 minutes (49.35 ± 19.98% and 33.69 ± 6.30, respectively). This re- sult could be related to the lower hardness of tablets prepared with stearic acid and different cellulose microcrystalline (67.5 and 49.4 N for formulations prepared with Avicel-PH 102 and
Avicel-PH 101, respectively). Higher hardness corresponds to a higher interaction among the particles, which could lead to the slow release of the drug 3. However, the formulation which presented the highest mean drug release 49.35% (Avicel-PH 101 and stearic acid) also presented a higher friability due to its low hardness value. All these formulations presented a lower amount of drug released compared to the drug dissolved after 30 minutes of the ASA raw mate- rial, under the same conditions (66.79 ± 6.22%).