How to transform injections into pills: an exciting adventure…in progress

Pills instead of injections

The topic of Dr. Irene Pereira de Sousa’s lecture was the way in which drugs, which are presently being administered via injection, could be formulated in form of pills in the future. Dr. De Sousa first introduced the problem associated with many modern drugs which are currently being developed by the pharmaceutical industry. The new direction drug development is taking is more and more towards “personalized” medicine and ad hoc drugs. Many of the new drugs being developed within these two areas are not “small molecules” anymore, such as aspirin or ibuprofen, but are larger molecules such as peptides or proteins, molecules even larger than peptides. The problem with peptides and proteins is that their building blocks are amino acids and in this way subject to the action of enzymes within the human bodies. Such enzymes have the function of breaking down the peptidic bond linking together amino acids and thus de facto breaking down the protein or peptide drug before it reaches the intestines, where they can be absorbed and transferred into the blood system.

Drugs overcome four barriers

In a simple and easily understandable way, Dr. Pereira De Sousa explained the four barriers a drug administered orally must overcome in the gastrointestinal tract in order to reach a patient’s intestine. There it can be absorbed by the tissue and transferred to the blood system – and go into effect. Each of the four barriers presents its own set of challenges. Peptide- and protein-based drugs have to pass the stomach and its acids unscathed, while finding a way to shield themselves from the action of enzymes, and, once they reach the intestine, permeate through the mucus to reach the epithelium. Once they are faced with the last hurdle which consists of passing the epithelial cells barrier, the drug finally reaches the blood stream.

No single solution

Several research groups around the world, including Dr. Pereira de Sousa’s, have been actively working on addressing specific aspects of the above-mentioned four barriers. A number of steps have been made in proposing ingenuous approaches, however, there is still much research work to be done in order to obtain a viable solution. As Dr. Pereira de Sousa pointed out, it may be that the research developments will lead to new ways of transforming injections into pills.