A highly absorbing substrate based on functionalized calcium carbonate for personalized dosing of clonidine by...

As precision medicine advances, the need for customizable drug delivery systems has become increasingly important. In this study, we developed porous tablets as substrates for drop-on dispensing of drug-containing ink in personalized doses. We evaluated this approach with clonidine hydrochloride, a hydrophilic drug prescribed in low doses for pediatric patients with hypertension. Porous tablets were compacted from functionalized calcium carbonate (FCC), a filler with a mesoporous structure that can absorb water-based ink without loss of tablet integrity. To improve the compactibility of FCC, the powder was dry granulated and mixed with two different binders: either microcrystalline cellulose (MCC) or ethylcellulose (EC). This was done in various ratios either intragranularly or extragranularly. Tablets (6 mm diameter × 1.6-1.7 mm thickness) with 9.5% (w/w) MCC as intragranular or with 5.0% (w/w) EC as extragranular binder could be loaded with 30 µl clonidine-containing ink. Dissolution experiments in acidic medium (pH 2.0 at 37 °C), mimicking the conditions of the stomach, showed release of clonidine with almost complete dissolution of the drug after 1-2 h. Our findings demonstrate the potential of FCC porous tablets as substrates for drop-on dispensing in the context of personalized dosing of medicines.