In vitro characterization of statistically optimized quetiapine‑loaded self‑nanoemulsified systems with quality by design

Objective: To optimize and characterize quetiapine (QP)‑loaded self‑nanoemulsified drug delivery systems (SNEDDS) by 3‑factorial 3‑level Box–Behnken design (BBD) to improve the dissolution. Methods: Amounts of olive oil (X1 ), tween 80 (X2 ), and PEG 400 (X3 ) as independent factors, whereas % limpidity (Y1), self‑emulsification time (SET) (Y2), and drug released at 15 min (T15) (Y3) as responses were employed in BBD. Three‑dimensional response surface plots were run to understand the main interaction and quadratic effects of independent variables. Preliminary screening was carried out by equilibrium solubility and emulsification efficiency studies. Nanoemulsification region was recognized by pseudoternary plot. Results: Mean droplet size of optimized nanodispersion was 89.68 nm, electrokinetic potential was−27.2 mV and polydispersity index<1 and represented 94% of limpidity, 69 s of SET, and 93.4% of T15. Software‑generated model graphs (predicted versus actual and residual versus predicted) for all three responses were produced without outliers and thus indicated the adequacy of selected statistical model. Conclusion: This study explained the effectiveness of BBD in insights of formulation variables and quality of QP‑loaded nanoemulsified systems so as to enhance dissolution. As a result, BBD was a well‑suitable experimental design in predicting the responses of QP‑loaded liquid SNEDDS.