Self-emulsifying drug delivery systems (SEDDS) represent an innovative approach to improving the solubility and bioavailability of poorly water-soluble drugs, addressing significant challenges associated with oral drug delivery. This review highlights the advancements and applications of SEDDS, including their transition from liquid to solid forms, while addressing the formulation strategies, characterization techniques, and future prospects in pharmaceutical sciences. The review systematically analyzes existing studies on SEDDS, focusing on their classification into liquid and solid forms and their preparation methods, including spray drying, hot-melt extrusion, and adsorption onto carriers. Characterization techniques such as droplet size analysis, dissolution studies, and solid-state evaluations are detailed. Additionally, emerging trends, including 3D printing, hybrid systems, and supersaturable SEDDS (Su-SEDDS), are explored. Liquid SEDDS (L-SEDDS) enhance drug solubility and absorption by forming emulsions upon contact with gastrointestinal fluids. However, they suffer from stability and leakage issues. Transitioning to solid SEDDS (S-SEDDS) has resolved these limitations, offering enhanced stability, scalability, and patient compliance. Innovations such as personalized 3D-printed SEDDS, biologics delivery, and targeted systems demonstrate their potential for diverse therapeutic applications. Computational modeling and in silico approaches further accelerate formulation optimization. SEDDS have revolutionized drug delivery by improving bioavailability and enabling precise, patient-centric therapies. While challenges such as scalability and excipient toxicity persist, emerging technologies and multidisciplinary collaborations are paving the way for next-generation SEDDS. Their adaptability and potential for personalized medicine solidify their role as a cornerstone in modern pharmaceutical development.

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.

This review investigates the progression and effectiveness of colon-targeted drug delivery systems, offering a comprehensive understanding of the colon's anatomy and physiological environment. Recognizing the distinctive features of the colon is crucial for successfully formulating oral dosage forms that precisely target specific areas in the gastrointestinal tract (GIT) while minimizing side effects through mitigating off-target sites. This understanding forms the basis for designing effective targeted drug delivery systems. The article extensively examines diverse approaches to formulating drugs for colonic targeting, highlighting key polymers and excipients in their production. Special emphasis is given to innovative approaches such as hot-melt extrusion (HME) and three-dimensional printing (3D-P), renowned for their accuracy in drug release kinetics and intricate dosage form geometry. However, challenges arise regarding material standardization and the complex network of regulatory clearances required to confirm safety and effectiveness. The review provides insights into each application’s advantages and potential challenges. Furthermore, it sheds light on the local diseases that necessitate colon targeting and the available marketed products, providing an overview of the current state of colon-targeted drug delivery systems. Additionally, the review emphasizes the importance of testing drugs in a controlled in vitro environment during the development phase. It also discusses the future directions for successful development in this field. By integrating knowledge across anatomy, formulation techniques, and assessment methodologies, this review is a valuable resource for researchers navigating the dynamic field of colonic drug delivery. Graphical Abstract

(2013). Development, evaluation and pharmacokinetics of time-dependent ketorolac tromethamine tablets. Expert Opinion on Drug Delivery: Vol. 10, No. 1, pp. 33-45. doi: 10.1517/17425247.2013.743528