Recent trends in the area of pharmaceutical products research and development appear to be directed more towards new drug delivery systems such as oro-dispersible films, as well as new physical forms of existing drugs such as co-crystals.
Adapting technologies from other fields for developing such systems can be beneficial. Thermal inkjet printing (TIJ), a technique commonly encountered in office printers, has found applications in different areas due to its advantageous properties. The aim of this work was to utilise this technique to develop oral films for personalised dosing and to investigate its potential as a rapid and inexpensive method to prepare pharmaceutical co-crystals. Two unmodified Hewlett-Packard printers were used where the ink cartridges were modified to accommodate polymeric and aqueous drug solutions. Films were successfully prepared by printing multiple layers of hydroxyl-propyl-methylcellulose solutions onto transparency films, which disintegrated faster than those prepared by solvent casting (SC).
Further, the amount deposited of a model drug (salbutamol sulphate, SS) varied linearly with the feed solution concentration. This led to the preparation of oral films using edible starch paper. Good agreement between the printed and theoretical dose was achieved with single print passes. Multiple print passes resulted in a significant loss, which was predictable and the dose variation was within the BP limits for SS tablets. Polymeric films were then used as substrates to prepare oral films of clonidine. Comparison with films prepared by solvent casting in terms of their physical stability, mechanical and drug release properties was also conducted. Films prepared by TIJ were more flexible and had better dose uniformity than films prepared by SC. Nonetheless, drug release from both films was similar. Finally, the technique was investigated to prepare pharmaceutical co-crystals. This was successfully achieved by printing solutions of co-crystal formers at specific stoichiometric ratios. In conclusion, this work demonstrates the suitability of TIJ as a method to prepare oral films extemporaneously for personalised dosing as well as pharmaceutical co-crystals.
Cr. UCL UK