The chemical nature of the molecules to be administered also plays an important role in the choice of route of administration. All molecules must be made soluble in order to pass through the intestinal barrier. Molecules that aren’t soluble in water, such as testosterone, immediately pose a problem as regards oral administration. This is the second reason why our testosterone couldn’t be given orally.

“Choosing the right dosage  form for every active ingredient is no small matter”, Brigitte Evrard stresses. “In fact, it lies at the basis of Pharmaceutical Technology (Pharmacie Galénique in French): the art of administering [a drug] is as important as [the composition of] what we give. It is derived from Galen, a doctor in ancient Rome, who was the first to think about choosing the most ‘suitable’ way to administer drugs to patients to obtain the desired effect. We can consider Galen as the true father of pharmacy, just as Hippocrates is considered the father of medicine.”

Hence, the aim of pharmaceutical technology is to optimise drug administration in order to reduce its side effects, improve the bioavailability of its active ingredients and, in addition, a more down-to-earth but no less important objective, to develop robust and reproducible manufacturing procedures (without which it is impossible to guarantee the product’s consistent quality – Read the box).

ULg's laboratory regularly collaborates with the pharmaceutical industry to develop drugs, whether they be 'conventional', rapid release (such as oral lyophilisates that melt on the tongue), or – on the contrary – sustained release such as enteric tablets, which allow targeted release in the intestines to treat Crohn’s Disease for instance. But Brigitte Evrard’s team focuses mainly on the less conventional administration routes, especially pulmonary and transnasal. Which brings us back to our female Viagra...

Why the transnasal route?

Testosterone has been on the market for a long time in an intravenous form, but these are products developed for men – with the aim of treating specific hormonal deficiencies but also for certain forms of doping... - and, be that as it may, for prolonged use. On the contrary, Tefina had to have a rapid effect. The key objective was to provoke a short peak in testosterone in the female brain (and not in the genital organs, which confirms that everything happens in the head...) in order to obtain the desired effect on female libido and sensitivity to pleasure. After the oral route, exit the intravenous route.