Date of this Version
A biologic drug is a drug that is produced by a living organism. Biologic drugs are used to treat various medical conditions such as arthritis, diabetes, or certain forms of cancers due to their high potency and high selectivity of action. Drawbacks of biologics include their poor stability in the gastrointestinal tract and their poor absorption. In effect, this gives the drugs very low bioavailability and short therapeutic half-lives. To combat these obstacles, current delivery methods include subcutaneous injections at home or intravenous or intramuscular injections in a medical facility.
The overall scientific goal of the research was to utilize subcutaneous needle injection methodology used for parenteral systemic biologic drug delivery to solve the problem of delivering biologics orally for treating diseases like diabetes, arthritis, or cancers. Previous prototype tissue attachment mechanism (TAM) systems have shown tissue attachment in vivo, without the delivery of a drug. The methodology of this study was to use the same successful device but integrate an osmotic pump and a hypodermic needle to deliver a drug after attachment to the intestine. The delivery of the drug was deemed successful based on the drug's concentration in blood samples.
The integrated TAM and drug delivery needle were designed, tested, and integrated on the benchtop until consistent successful drug delivery results were obtained. Once the device reliably delivered drug on excised tissue, it was tested in vivo on six swine for systemic drug delivery. The first study had shorter than expected TAM attachment times causing minimal drug to be delivered, but the methodology of the study was learned. After improving the device and study setup, a second in vivo study was performed on another six swine. The study showed much stronger evidence of drug delivery. Both positive controls and one of the three experimental groups showed systemic drug delivery. Both studies were a methods development study, so the number of pigs in the results did not meet the power for statistical significance.
Also, in this work, a theoretical osmotic pump was designed to be integrated with the TAM and full capsule. Although not actually fabricated, the osmotic pump would be fabricated using the same material and ratio of drug to total volume as a commercial osmotic pump. The commercial osmotic pump was tested in a swine small intestine and showed proof of drug delivery.
Advisor: Benjamin Terry