Quetiapine fumarate (QTF) was approved for the treatment of schizophrenia and acute manic episodes. QTF can also be used as an adjunctive treatment for major depressive disorders. QTF oral bioavailability is limited due to its poor aqueous solubility and pre-systemic metabolism. The objective of the current investigation was the formulation development and manufacturing of solid self-nanoemulsifying drug delivery system (S-SNEDDS) formulation through a single-step continuous hot-melt extrusion (HME) process to address these drawbacks. In this study, Capmul^® MCM, Gelucire^® 48/16, and propylene glycol were selected as oil, surfactant, and co-surfactant, respectively, for the preparation of S-SNEDDS. Soluplus^® and Klucel™ EF (1:1) were selected as the solid carrier. Response surface methodology in the form of central composite design (CCD) was utilized in the current experimental design to develop the S-SNEDDS formulations via a continuous HME technology. The developed formulations were evaluated for self-emulsifying properties, particle size distribution, thermal behavior, crystallinity, morphology, physicochemical incompatibility, accelerated stability, and in vitro drug release studies. The globule size and emulsification time of the optimized SNEDDS formulation was 92.27 ± 3.4 nm and 3.4 ± 3.38 min. The differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies revealed the amorphous nature of the drug within the formulation. There were no drug-excipient incompatibilities observed following the Fourier transform infrared (FTIR) spectroscopy. The optimized formulation showed an extended-release profile for 24 h. The optimized formulation was stable for three months (last time-point tested) at 40 °C/75% RH. Therefore, the developed S-SNEDDS formulation could be an effective oral delivery platform for QTF and could lead to better therapeutic outcomes.

Background/Objectives: Cannabidiol (CBD) is a non-psychoactive phytocannabinoid, with numerous therapeutic applications. It can be used to treat pain, inflammation, anxiety, and schizophrenia and it is also used to treat severe forms of infant epilepsy. CBD is a highly lipophilic compound with low oral bioavailability due to poor aqueous solubility and extensive first-pass metabolism. Self-emulsifying drug delivery systems (SEDDSs) offer a promising approach to enhancing the solubility and stability of lipophilic compounds like CBD. This study aimed to design and optimize CBD-loaded solid SEDDSs (S-SEDDSs) using Response Surface Methodology (RSM) to identify the optimal formulation parameters for improved drug release and stability. Methods: Excipients were selected through qualitative screening studies, considering their functional properties in SEDDS development. A Central Composite Design (CCD) was employed for response surface optimization to evaluate the effect of independent variables on formulation performance, including oil concentration and the surfactant–co-surfactant ratio. Formulations were processed using hot-melt extrusion (HME). The lead formulation was tested for drug content, in vitro drug release and stability studies. Results: The solid SEDDS formulation showed a drug content of 98.15 ± 1.94% and achieved 76.6 ± 0.6% drug release within three hours during in vitro dissolution testing, compared to 28 ± 0.9% for pure CBD. During stability testing, the lead formulation showed minimal change at both 25 °C and 40 °C. Conclusions: Overall, the study demonstrated that RSM-guided formulation development combined with HME processing can produce CBD S-SEDDSs and improve in vitro drug release compared to pure CBD.