**6. Conclusions**

Pharmacotherapy of children's population is an important matter in a field of modern pharmaceutical technology. The main problems regarding children treatment result from the diversity of the paediatric population, as well as a relatively small number of appropriate dosage forms, including modern ones. Creating children-made formulation is challenging but an essential task in formulating an appropriate dosage form, which should be adjustable for a wide range of ages, palatable, easy to administer, but first of all safe and effective. Key aspects in modern formulations involve development of novel MR formulations (minitablets, pellets, MR oral liquid formulations) when considering chronic diseases that affects children and minimizing the dose frequency. Simultaneously, safety of excipients and child's acceptability should be kept in mind. The limited number of MR formulation in the market (especially for children under six-years) arise from the high cost of technologies and lack of relevant clinical trials in the paediatric population. Therefore, new regulations and additional funding opportunities, as well as innovative collaborative research initiatives should be constantly developed.

**Author Contributions:** Conceptualization, M.T., K.W. (Katarzyna Wasilewska) and K.W. (Katarzyna Winnicka); Writing-Review & Editing, M.T., K.W. (Katarzyna Wasilewska) and K.W. (Katarzyna Winnicka); Visualization, M.T., K.W. (Katarzyna Wasilewska); Supervision, K.W. (Katarzyna Winnicka); Project Administration, M.T.; Funding Acquisition, K.W. (Katarzyna Wasilewska) and K.W. (Katarzyna Winnicka).

**Funding:** This research was funded by Medical University of Bialystok gran<sup>t</sup> N/ST/MN/16/002/2215, N/ST/MN/17/001/2215 and N/ST/MN/18/002/2215.

**Conflicts of Interest:** The authors declare no conflict of interest.
