Many active ingredients pose a serious problem for pharmaceutical researchers. They are poorly water-soluble and therefore dissolve very inadequately or only very slowly in bodily fluids, for instance gastric juices. As a result, only a small proportion is dissolved and absorbed via the stomach wall or intestinal mucous membrane into the blood circulation whereas a much larger proportion of the active ingredient is simply excreted. Even among those active ingredient molecules reaching the blood circulation, however, only a small proportion of those reach the organ targeted for treatment. A much larger proportion is passed out with the urine. In this context, developers talk about “poor bio-availability”.
In order to improve bio-availability, pharmaceutical formulators are trying to increase the dissolvability of pharmaceutical substances with poorly water-soluble active ingredients. “We are combining micronising technologies with our LBL-Technology,” explains Christoph Dunmann, Project Director at Capsulution. Thanks to the enlarged surfaces, the stabilizing particles interact more easily with and dissolve more rapidly in the watery bodily fluids. The tenside-free formulations are extremely palatable. By decreasing the therapeutic dose, the danger of side-effects is further reduced.
“In the current study, we investigated the pharmaceutical kinetics of an extremely poor water-soluble model substance with a solubility of less than 40 mg per litre with oral administration in rats,” continued Dunmann. Various nano-particle-based LBL formulations were tested, in which the poly-electrolytes applied as well as the number of layers varied. In comparison to the unformulated active ingredient, the bio-availability in all the LBL formulations was significantly increased.
Following the successful study on animals, Capsulution is setting course for rapid development. A second animal study on the oral bio-availability is already on the programme for the first half of this year. Also planned are the improvement in the formulation of nano-suspensions for intravenous administration and formulations for subcutaneous and intra muscular dosage with an additional depot effect. There is also work on a non-invasive method of bringing active ingredients into the eye.