Development and Optimization of Sildenafil Orodispersible Mini-Tablets (ODMTs) for Treatment of Pediatric Pulmonary Hypertension Using Response Surface Methodology

The availability of age-appropriate oral dosage forms for pediatric patients has remained a challenge. Orodispersible mini-tablets (ODMTs) are a promising delivery system for pediatric patients. The purpose of this work was the development and optimization of sildenafil ODMTs as a new dosage form for the treatment of pulmonary hypertension in children using a design-of-experiment (DoE) approach. A two-factor, three levels (3(2)) full-factorial design was employed to obtain the optimized formulation. The levels of microcrystalline cellulose (MCC; 10-40% w/w) and partially pre-gelatinized starch (PPGS; 2-10% w/w) were set as independent formulation variables. In addition, mechanical strength, disintegration time (DT), and percent drug release were set as critical quality attributes (CQAs) of sildenafil ODMTs. Further, formulation variables were optimized using the desirability function. ANOVA analysis proved that MCC and PPGS had a significant (p < 0.05) impact on CQAs of sildenafil ODMTs with a pronounced influence of PPGS. The optimized formulation was achieved at low (10% w/w) and high (10% w/w) levels of MCC and PPGS, respectively. The optimized sildenafil ODMTs showed crushing strength of 4.72 +/- 0.34 KP, friability of 0.71 +/- 0.04%, DT of 39.11 +/- 1.03 s, and sildenafil release of 86.21 +/- 2.41% after 30 min that achieves the USP acceptance criteria for ODMTs. Validation experiments have shown that the acceptable prediction error (<5%) indicated the robustness of the generated design. In conclusion, sildenafil ODMTs have been developed as a suitable oral formulation for the treatment of pediatric pulmonary hypertension using the fluid bed granulation process and the DoE approach.