In Vivo Evaluation of a Gastro-Resistant Enprotect® Capsule under Postprandial Conditions

Development and evaluation of innovative enteric-coated capsules for colon-specific delivery of hydrophilic biomaterials

OBJECTIVE

This research aims to design and evaluate an enteric-coated hard capsule dosage form for targeted delivery of biological materials, such as FMT (fecal microbiota transplant) or live microbes, to the distal parts of the GIT. The capsules are designed to be internally protected against destruction by hydrophilic filling during passage through the digestive tract.

METHODS

Hard gelatin capsules and DRcapsTMcapsules based on HPMC and gellan were used to encapsulate a hydrophilic body temperature-liquefying gelatin hydrogel with caffeine or insoluble iron oxide mixture. Different combinations of polymers were tested for the internal (ethylcellulose, Eudragit® E, and polyvinyl acetate) and external (Eudragit® S, Acryl-EZE®, and cellacefate) coating. The external protects against the acidic gastric environment, while the internal protects against the liquid hydrophilic filling during passage. Coated capsules were evaluated using standard disintegration and modified dissolution methods for delayed-release dosage forms.

RESULTS

Combining suitable internal (ethylcellulose 1.0 %) and external (Eudragit® S 20.0 %) coating of DRcapsTM capsules with the wiping and immersion method achieved colonic release times. While most coated capsules met the pharmaceutical requirements for delayed release, one combination stood out. Colonic times were indicated by the dissolution of soluble caffeine (during 120-720 min) measured by the dissolution method, and capsule rupture was indicated by the release of insoluble iron oxide (after 480 min) measured by the disintegration method. This promising result demonstrates the composition's suitability and potential to protect the content until it's released, inspiring hope for the future of colon-targeted delivery systems and its potential for the pharmaceutical and biomedical fields.

CONCLUSION

Innovative and easy capsule coatings offer significant potential for targeted drugs, especially FMT water suspension, to the GIT, preferably the colon. The administration method is robust and not considerably affected by the quantity of internal or external coatings. It can be performed in regular laboratories without specialized individual and personalized treatment equipment, making it a practical and feasible method for drug delivery.

Use of Magnetic Resonance Imaging for Visualization of Oral Dosage Forms in the Human Stomach: A Scoping Review

Oral dosage forms are the most widely and frequently used formulations to deliver active pharmaceutical ingredients (APIs), due to their ease of administration and noninvasiveness. Knowledge of intragastric release rates and gastric mixing is crucial for predicting the API release profile, especially for immediate release formulations. However, knowledge of the intragastric fate of oral dosage forms in vivo to date is limited, particularly for dosage forms administered when the stomach is in the fed state. An improved understanding of gastric food processing, dosage form location, disintegration times, and food effects is essential for greater understanding for effective API formulation design. In vitro standard and controlled modeling has played a significant role in predicting the behavior of dosage forms in vivo. However, discrepancies are reported between in vitro and in vivo disintegration times, with these discrepancies being greatest in the fed state. Studying the fate of a dosage form in vivo is a challenging process, usually requiring the use of invasive methods, such as intubation. Noninvasive, whole body imaging techniques can however provide unique insights into this process. A scoping review was performed systematically to identify and critically appraise published studies using MRI to visualize oral solid dosage forms in vivo in healthy human subjects. The review identifies that so far, an all-purpose robust contrast agent or dosage form type has not been established for dosage form visualization and disintegration studies in the gastrointestinal system. Opportunities have been identified for future studies, with particular focus on characterizing dosage form disintegration for development after the consumption food, as exemplified by the standard Food and Drug Administration (FDA) high fat meal.