3D-printed spironolactone gel tablets for children pass quality tests

GERPAC Congress 2026 highlights

Spironolactone gel tablets for paediatric patients can be reliably and reproducibly 3D printed in the hospital pharmacy at doses from 4 to 20 mg, according to Tamás Vincze (Department of Pharmacy, University Medical Center of Johannes Gutenberg University, Mainz).

Spironolactone is widely used in children with heart failure, and doses must be individualised by body weight. 3D printing allows pharmacies to prepare single-dose tablets in patient-specific doses over a wide range, according to a medical prescription. Gel tablets also have practical advantages for children: they are easy to administer and swallow and they taste better than conventional tablets.

The printing ink contained 2% spironolactone and 2.6% polysorbate 80 in Curablend® gel tablet excipient base, mixed by centrifugation. Gel tablets were printed at 41°C into blister packs on a Pharma Printer (CurifyLabs) with an integrated balance. Different doses were obtained by varying the tablet weight: 200 mg for 4 mg tablets, 500 mg for 10 mg and 1,000 mg for 20 mg. Three batches of 30 tablets of each strength were printed on three different days. To measure drug content, the team developed and validated a stability-indicating HPLC-UV assay adapted from the USP monograph for spironolactone tablets. Ten tablets from each batch were analysed.

The HPLC assay met all the validation criteria for linearity, precision and accuracy. Placebo tablets and forced degradation studies confirmed that no other peaks overlapped with the spironolactone peak. Mean drug content was 101.3%, 103.5% and 104.8% of the nominal content for the 4 mg, 10 mg and 20 mg tablets, respectively. All batches met the European Pharmacpoeia requirements for content (85–115%), content uniformity (acceptance values 2.8–12.9, below the limit of 15) and uniformity of mass.

The authors concluded that the HPLC assay is robust and reliable, and that pharmacy preparation of 3D-printed spironolactone gel tablets is precise and reproducible. Further tests of water content, stability, disintegration and dissolution are ongoing.

Vincze T, Tubic-Grozdanis M, Krämer I et al. Preparation and quality control of 3D printed spironolactone gel-tablets for paediatric patients. Poster. GERPAC Congress 2026.