Gastrointestinal Degradation
Gastric conditions, intestinal fluids and local chemical environments may denature or destabilise sensitive macromolecules.
Technology platform
Oral delivery of macromolecules is a multi-barrier problem.
Proteins, peptides and nucleic acids must remain sufficiently intact in the gastrointestinal environment, move through or interact appropriately with mucus, reach the epithelium, cross cellular barriers and release in a useful form. Improving one step does not ensure overall delivery.
The delivery barriers
Why oral biologic delivery is difficult
The oral route presents a sequence of changing chemical, enzymatic and biological conditions. Formulation development must identify the dominant failure points for a specific payload and product concept.
Enzymatic Degradation
Proteases, peptidases, nucleases and other digestive enzymes can reduce payload integrity before it reaches an absorptive surface.
Poor Epithelial Permeability
Large molecular size, polarity and charge generally restrict passive transport across intestinal epithelial membranes and tight junctions.
Mucus Barrier
Mucus can trap particles, slow diffusion, alter nanoparticle transport and reduce access to the epithelial surface.
Changing GI Conditions
pH, enzymes, bile salts, food effects, fluid composition and transit time vary along the tract and may alter particle structure or payload stability.
Low & Variable Bioavailability
Payload survival alone is insufficient. Adequate and reproducible interaction with the intestinal barrier is also required.
Intracellular Barriers
After uptake, some payloads may encounter endosomal sequestration, intracellular degradation, inefficient release or limited access to their target.
Translation Trade-Offs
Protection or permeability strategies must also remain stable, reproducible, biologically acceptable and feasible to manufacture.
“Nanocarriers may improve protection and interaction with biological barriers, but successful oral delivery requires the simultaneous control of gastrointestinal stability, mucus transport, epithelial uptake and payload release.”
Nanomedicine strategy
Coordinating protection, interaction and release
Nanoparticle and vesicle-based systems offer a potential strategy for integrating several formulation functions. Their contribution must be demonstrated under conditions relevant to the intended oral product.
Payload Protection
Reduce direct exposure to destabilising or degradative environments where feasible.
GI Stability
Maintain relevant particle and payload attributes as conditions change.
Mucus Interaction
Evaluate retention, diffusion and access to the epithelial surface.
Epithelial Contact
Control surface interactions while maintaining compatibility.
Cellular Uptake
Assess association, internalisation and relevant transport pathways.
Payload Release
Enable release while preserving the payload's required integrity.
Potential platforms
Selecting a formulation architecture
The most appropriate system depends on the molecule, gastrointestinal failure mode, intended site of action and product constraints.
These platforms may improve dispersion or solubilisation, modify interaction with mucus, increase epithelial contact, facilitate cellular uptake or control release. Each possible function requires fit-for-purpose evidence.
Development reality
Nanocarriers do not automatically solve oral bioavailability
A system may protect a payload yet remain trapped in mucus, reach the epithelium without crossing it, or enter cells without releasing effectively. Development therefore connects formulation characterisation with staged barrier-relevant evaluation.
Formulation Stability
Assess payload and particle attributes in relevant simulated gastrointestinal conditions, including the impact of dilution and environmental change.
Barrier-Relevant Evaluation
Use fit-for-purpose studies to examine mucus interaction, epithelial compatibility, cellular association, uptake and permeability.
Translational Feasibility
Consider formulation robustness, storage, reproducibility, scale-up and practical administration alongside biological performance.
Project collaboration
Frame an oral-delivery feasibility study.
Share the payload, target site or exposure profile, current formulation evidence and the barriers most relevant to your programme. We can help define a focused sequence of formulation and in vitro questions.