Colon-Targeted Delivery Formulation Development for Live Biotherapeutic Products

We use a validated sequential pH-step dissolution protocol that mimics the physiological conditions of each GI segment. Formulations are exposed to simulated gastric fluid (SGF, pH 1.2, 2 hours), followed by simulated intestinal fluid (SIF, pH 6.8, 1 hour), and then simulated colonic fluid (SCF, pH 7.2, supplemented with a representative colonic enzyme preparation). At each transition, we sample for cumulative bacterial release and viable count (CFU/mL). This approach generates a complete release and survival profile across the full transit sequence, rather than a single endpoint measurement.

Polymer selection begins with a compatibility screen—we test a panel of candidate materials directly against your strain under controlled conditions to identify any viability-suppressing interactions before committing to coating trials. We then evaluate coating performance (pH dissolution threshold, coating integrity at gastric pH) for the compatible candidates. Selection criteria include dissolution profile, coating weight gain efficiency, batch reproducibility, and compatibility with your intended dosage form. The output is a ranked shortlist with supporting data, not a single prescriptive recommendation.

Yes. Our formulation development workflows accommodate both Gram-positive strains (such as Lactobacillus and Bifidobacterium species) and Gram-negative candidates (such as engineered Escherichia coli strains). Because Gram-negative organisms differ in membrane structure and acid sensitivity, we adapt the viability assessment protocol and the coating compatibility screen to reflect strain-specific stress responses. Project scoping discussions allow us to tailor the experimental design to your organism's particular characteristics.

pH-responsive release relies on the dissolution of an enteric polymer coating at colonic pH (typically ≥6.8–7.4). Enzyme-triggered release uses colonic bacterial enzymes—such as pectinase or inulinase—to degrade a polysaccharide matrix, providing a second layer of site-specificity because those enzymes are produced almost exclusively in the colon. For programs where the target site must be precisely controlled (for example, distinguishing between proximal and distal colonic delivery), combining both mechanisms in a single formulation architecture substantially improves site selectivity. Whether a dual system is warranted depends on your indication, your strain's pH tolerance profile, and the regulatory expectations for your development program—all of which we assess during project scoping.

Our stability studies are designed with downstream regulatory use in mind. We document methods, acceptance criteria, environmental conditions, and data analysis in a format consistent with ICH Q1A guidance and CMC module expectations for biological investigational products. That said, we recommend reviewing the specific regulatory submission requirements with your regulatory affairs team early in the project—this allows us to align the study design and documentation format to your specific filing jurisdiction and product category from the outset.