Gastrointestinal-Targeted Drug Delivery Systems

CD Bioparticles offers a comprehensive platform for the design, synthesis, ligand conjugation, modification, and evaluation of drug delivery carriers based on nano-carriers for Gastrointestinal tract targeting. Our professional carrier construction, combined with in vivo and in vitro analysis and characterization, enables us to provide a range of products and services that meet the unique needs of Gastrointestinal tract targeted drug delivery systems. We provide full support for early development, leveraging the specific characteristics of the Gastrointestinal tract to ensure optimal efficacy.

Introduction to GI-Targeted Drug Delivery Systems

The gastrointestinal (GI) tract is composed of four major compartments that play a critical role in drug release and absorption: the mouth, stomach, small intestine, and large intestine. Each section of the GI tract has distinct biochemical, acidic, fluid, and enzyme characteristics that pose targeting challenges for orally administered drugs. In Figure 1, the pH characteristics of the gastrointestinal tract are presented (alongside the controlled release attributes of a typical pH-responsive material). When drugs have poor solubility, stability, and bioavailability, treating diseases through oral administration can be especially difficult. Various approaches have been explored to overcome these limitations, with the nano-delivery system gaining particular attention. Drug-loaded nano-carriers such as polymeric nanoparticles, lipid nanoparticles, inorganic nanoparticles, micelles, nano-emulsions, and liposomes have been developed to improve drug dispersion, solubility, and stability. These methods also offer potential for gastrointestinal absorption of peptide drugs and vaccines. Local treatments for gastrointestinal diseases like gastritis, Crohn's disease, gastrointestinal cancer, and systemic diseases like diabetes, neurological disease, and vaccines require efficient drug delivery systems to overcome the gastrointestinal biological barrier and enhance local targeting^[1].

Figure 1. Schematic model of gastrointestinal tract. Each segment has different pH values and epithelial characteristics.

The Specific Features of GI-targeted Drug Delivery Systems:

Different drugs target different sites based on the physiological characteristics of those sites. Table 1 below highlights some of these features:

Table 1. Features for gastrointestinal response.

The Applications of GI-targeted Drug Delivery Systems:

Targeted drug delivery systems have been developed to improve the efficiency and efficacy of drug delivery in different parts of the gastrointestinal tract.

• In the stomach, gastro-retentive devices such as floating systems and pH-dependent adhesion have been used to prolong drug retention and achieve sustained drug release. High molecular weight materials such as Eudragit are a series of acrylic resins that have been widely used as coating materials for gastrointestinal controlled release preparations.
• In the mucus layer, materials such as PEG and Poloxamer/Pluronic have been used for mucus-penetrating or mucus-interacting systems.
• The small intestine, with its large surface area and rich villi, provides a suitable environment for absorption, and safe oral formulations have been successfully used to improve the bioavailability of easily degraded peptide drugs.
• For colon-targeted drug delivery, biodegradable polymers that are specifically degraded by microflora in the colon have been used.

All of these targeted drug delivery systems have the potential to improve the efficacy and safety of drug treatments for various diseases^[2].

Our Featured Services:

• Design and synthesis: Our services include selection and synthesis of carriers such as dendrimers, polymer nanoparticles, liposomes and lipid nanoparticles depend on the different therapeutic purposes and positions including the mucus, epithelium and segments of the stomach and intestines.
• Ligand conjugation and chemical modification: CD Bioparticles provides conjugation services for a variety of molecules including synthetic polymer, small molecular compound, proteolytic enzyme, natural polysaccharide, natural protein, etc. Table 2 lists some typical materials reported for the modification of nano-carriers (Incomplete, located at the bottom of this page.)
• Analysis and characterization: We offer analysis and characterization services for size, surface properties, encapsulation efficiency, gene expression efficiency, purity, and more.
• Cell toxicity, dose determination, pharmacokinetic assessment, and off-target effect evaluation.

Table 2 Typical materials for the nano-carriers

Quotations and Ordering

References

1. Wang W, Yan X, Li Q, Chen Z, Wang Z, Hu H: Adapted nano-carriers for gastrointestinal defense components: surface strategies and challenges. Nanomedicine 2020, 29:102277.
2. Subramanian DA, Langer R, Traverso G: Mucus interaction to improve gastrointestinal retention and pharmacokinetics of orally administered nano-drug delivery systems. J Nanobiotechnology 2022, 20(1):362.