Inkjet Printing of T3 and T4 Oral Drug Combinations as a Novel Strategy for Hypothyroidism
Hypothyroidism is a chronic and debilitating disease that is estimated to affect 3% of the general population. Clinical experience has highlighted the synergistic value of combining triiodothyronine(T) and thyroxine (T ) for persistent or recurrent symptoms. However, thus far a platform that enables the simultaneous and independent dosing of more than one drug for oral administration has not been developed. Thermal inkjet (TIJ) printing is a potential solution to enable the dual deposition of T and T onto orodispersible films (ODFs) for therapy personalisation. In this study, a two-cartridge TIJ printer was modified such that it could print separate solutions of T and T . Dose adjustments were achieved by printing solutions adjacent to each other, enabling therapeutic T (15–50 μg) and T dosages (60–180 μg) to be successfully printed. Excellent linearity was observed between the theoretical and measured dose for both T and T (R = 0.982 and 0.985, respectively) by changing the lengthof the print objective (Y-value). Rapid disintegration of the ODFs was achieved (< 45 seconds). As such, this study for the first time demonstrates the ability to produce personalised dosecombinations by TIJ printing T andT onto the same substrate for oraladministration.