Preparation and characterization of soluplus-based nanosuspension for dissolution enhancement of indomethacin using ultrasonic assisted precipitation method for formulation and Box-Behnken design for optimization.

Objectives: Nanosuspensions are increasingly recognized as a valuable technology for enhancing poorly water-soluble drugs' solubility and dissolution rate, thereby improving their bioavailability. In this study, we employed ultrasonic-assisted precipitation to fabricate nanosuspensions of indomethacin (IND), utilizing Soluplus^® (Sol) as a stabilizing agent. Our objectives were driven by hypotheses centered on optimizing formulation variables and developing predictive models for optimal IND formulations.

Significance: This research highlights the Box-Behnken design (BBD) as a powerful tool that optimizes the properties of IND nanosuspensions, thus significantly enhancing their dissolution rate.

Methods: The impacts of the independent variables on the mean particle size (MPS), polydispersity index (PDI), and zeta potential (ZP) were investigated using BBD. The optimized nanosuspension was freeze-dried with 3% trehalose to produce a dry nanosuspension (DNS). The DNS was characterized by SEM, DSC, XRPD, solubility, and dissolution.

Results: The IND: Sol ratio and sonication power significantly affected the MPS and ZP of the nanosuspensions. The optimized formulation showed MPS, PDI, and ZP of 144.77 ± 6.68 nm, 0.26 ± 0.08, and -24.6 ± 1.90 mV, respectively. The DNS exhibited spherical particle morphology. The DSC and XRPD confirmed the amorphous state of IND with enhanced solubility and dissolution of IND. DNS showed a 3.7-fold increase in drug release in the first 15 min compared with raw IND.

Conclusions: This study demonstrated the critical role of BBD in accurately predicting the values of independent variables essential for formulating optimal nanosuspensions. These formulations possess specific properties that can be effectively integrated into various dosage forms tailored for different routes of administration.