Inflammatory bowel disease (IBD) is a common disease characterized by chronic inflammation in gastrointestinal tracts, which is primarily treated by administering anti-inflammatory and immunosuppressive drugs that inhibit the burden of intestinal inflammation and improve disease-related symptoms. However, the established therapeutic strategy has limited therapeutic efficacy and adverse drug reactions. Therefore, new disease-targeting drug-delivery strategies to develop more effective treatments are urgent. This review provides an overview of the drug-targeting strategies that can be used to treat IBD, and our recent attempts on the colon-specific delivery system (Pae-SME-CSC) with a paeonol-loaded self-microemulsion (Pae-SMEDDS) are introduced.

Natural products derived from traditional Chinese medicine have received significant attention as potential treatments for neurodegenerative disorders due to their wide availability, demonstrated efficacy, and favorable safety profiles. Intranasal delivery provides distinct advantages for targeting the central nervous system (CNS), enabling direct therapeutic agent delivery to the brain by bypassing the blood-brain barrier (BBB). This review evaluates natural products administered intranasally for neurodegenerative diseases (NDs), highlighting their therapeutic potential and addressing formulation challenges related to physicochemical properties. Strategic optimization approaches are proposed, including novel carrier systems, molecular modifications, and combination therapies. By discussing current difficulties and offering practical recommendations, this review aims to encourage further scholarly research and clinical application.

Objective: To develop a stable nanoemulsion loaded with Magnoliae Flos essential oil (MEO-NE) and evaluated its potential as an enhancer for nose-to-brain delivery in both solution and gel formulations. Methods: The MEO-NE was prepared using a low-energy emulsification method, with the formulation optimized via single-factor experiments and Box–Behnken design-response surface methodology. The optimized MEO-NE was characterized for particle size, PDI, morphology, and nasal mucosal irritation. Ex vivo histological imaging in rats was performed using hydrophilic sulfo-cyanine7 carboxylic acid and lipophilic coumarin 6 as fluorescent probes to assess distribution and retention in the trigeminal nerve and brain tissues. Results: The optimized MEO-NE exhibited a small particle size (27.96 ± 0.94 nm), low PDI (0.089 ± 0.013), spherical morphology, a stable O/W structure, and no irritation to the nasal mucosa. Ex vivo imaging revealed that MEO-NE significantly enhanced the distribution and retention of both hydrophilic and lipophilic probes in the trigeminal nerve and brain tissues. Moreover, the gel formulation of MEO-NE demonstrated superior brain-targeting efficiency over the solution within 6 h. Conclusions: MEO-NE served as an effective enhancer for nose-to-brain delivery, improving brain uptake of both hydrophilic and lipophilic drugs, and provided an experimental basis for utilizing herbal essential oils in CNS-targeted delivery systems.