Tailored Borneol-Modified Lipid Nanoparticles Nasal Spray for Enhanced Nose-to-Brain Delivery to Central Nervous System Diseases

The review of nasal drug delivery system: The strategies to enhance the efficiency of intranasal drug delivery by improving drug absorption

Nasal drug administration constitutes an efficient and non-invasive modality of drug delivery, and its distinctive physiological structure offers potentialities for treating a variety of diseases. To elevate the drug absorption and delivery efficiency, it is of paramount importance to delineate the transport routes and their enhancement mechanisms. Nevertheless, drug absorption pathways vary depending on the disease target, these variations present opportunities for targeted delivery and challenges for achieving precision. Hence, this review outlines the anatomical structure of the nasal cavity, and subsequently elaborates on the drug transport pathways within the nasal cavity and their influencing factors. Based on the distinct sites of drug action, diseases suitable for nasal drug administration are categorized into three types: systemic diseases, local nasal diseases, and central nervous system diseases. Grounded on multiple transport routes and their influencing factors, this review proposes strategies like optimizing formulation viscosity, using penetration enhancers, adding mucosal adhesives and improving delivery device, offering insights into future advancements in nasal drug delivery systems.

Advancements in Nanocarrier Systems for Nose-to-Brain Drug Delivery

In recent decades, nose-to-brain drug delivery has shown effectiveness in treating many central nervous system diseases. Intranasally administered drugs can be delivered to the brain through the olfactory and trigeminal pathways that bypass the blood-brain barrier. However, nose-to-brain drug delivery is challenging due to the inadequate nasal mucosa absorption of drugs and the short retention time of the intranasal formulations. These problems can be minimized through the use of nano-drug delivery systems, such as micelles, polymeric nanoparticles, nanoemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers. They can enhance the drug's bioavailability in the brain via increases in drug solubility, permeation, and stability. Nose-to-brain nano-drug delivery systems have been evaluated in vivo by a number of research groups. This review aims to provide an overview of nose-to-brain delivery and recent advances in the development of nano-drug delivery systems for delivering drugs from the nose to the brain to improve the treatment of some central nervous system diseases.

Permeation enhancer decorated nanoparticles for oral delivery of insulin: manipulating the surface density of borneol and PEG for absorption barriers

Oral protein drugs' delivery faces challenges due to multiple absorption barriers for macromolecules. Co-administration with permeation enhancers and encapsulation in nano-carriers are two promising strategies to enhance their oral absorption. Herein, the poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are decorated with polyethylene glycol (PEG) and a traditional Chinese medicine-derived permeation enhancer borneol (BO) for oral insulin delivery. Compared with a physical mixture of BO and PEG-decorated PLGA NPs, PLGA-PEG-BO NPs significantly facilitate insulin permeation across intestinal epithelia through various transcytosis pathways. The relationship among the BO surface density, physico-chemical properties and multiple barriers penetration ability is further investigated. Increasing the BO density boosts penetration through the epithelial cell layer but reduces enzyme and mucus barrier penetration. When the surface PEG density is at 90% and BO density is at 10%, the NPs possess the strongest overall ability to overcome both the mucus layer barrier and epithelial cell barrier, as illustrated by the highest permeation efficiency through Caco-2/HT29-MTX cell co-cultural monolayers. In diabetic rodents, PLGA-PEG90%-BO10% NPs exhibit high intestinal safety and a substantial hypoglycemic effect, with insulin availability at 6.22 ± 2.30%, double that of orally delivered insulin PLGA-PEG NPs and far superior to a physical mixture with BO. This study reveals the importance of tailored absorption enhancer decoration for oral protein delivery.