Miriam Robota, Head of Formulation Services, Evonik, has dedicated her research to uncovering innovative formulations for targeted oral drug delivery. Oral delivery is the most accepted route of administration and the most patient-friendly.
Robota focused on combining conventional production processes like capsules, tablets, and multiparticulates with unique formulation strategies to improve oral drug delivery, specifically using specialised coatings for site-specific release in the gastrointestinal tract. APIs have a strong effect on the gastrointestinal tract. Robota’s goal is to specifically target the API to a specific site of action with the intention of increasing the concentration of the active at the site of absorption, which is typically the duodenum.
Inflammatory bowel disease is one main example of a local release of the active. Increasing the concentration of the API at the site of absorption can increase the bioavailability, which in turn leads to dose reduction, probably fewer side effects, and has implications for cost reduction because the API could be expensive.
She wanted to focus on single or multiple layer coatings and observe how one could adjust the enteric properties of such a formulation to achieve high concentrations at the site of absorption. Next, Robota introduced EUDRAGIT polymers, a family of polymethacrylate polymers tailored for GI-targeted delivery, which can be processed in either aqueous formulations or solvent-based formulations.
The chemical structure of these polymers and their different functional groups enable immediate, enteric, or sustained release, allowing precise targeting within the GI tract. These polymers are useful for taste and odour masking.
To demonstrate their real-world use, Robota presented a case study assessing the efficacy of intestinal and colonic delivery of these coated capsules both in vitro and in vivo in volunteers. More specifically, the case study demonstrated the effectiveness of coated HPMC capsules using EUDRAGIT L 30 D-55 and FS 30 D for intestinal and colonic delivery, respectively. In vitro and in vivo tests confirmed precise release profiles and strong enteric protection.
To simplify formulation, Evonik developed pre-coated, ready-to-fill capsules called EUDRACAP that offer enteric protection without additional processing. These capsules showed impeccable acid resistance and rapid release at intestinal pH levels. Further testing with omeprazole and caffeine confirmed consistent performance and suitability for sensitive APIs. To sum up, Robota showed how reworking and tweaking conventional drug delivery processes with reproducible polymers can achieve precise and patient-centric drug delivery solutions.
