Formulation and in vitro – in silico characterization of prolonged-release prednisolone acetate spheroids

Aims The aims of this study were to develop alginate-based spheroid formulations for the prolonged release of prednisolone acetate, their in vitro and in silico characterization, and identification of formulation key factors influencing drug release behavior.Methods Prednisolone acetate spheroids were prepared by extrusion using 2% and 2.5% sodium alginate solutions and different needle diameters. Spheroids containing 30 mg of the drug were filled into gastro-resistant capsules, while controls contained pure drug. Content of prednisolone acetate and calcium, loss on drying, flow properties, dissolution behavior, FTIR spectra, and in silico regional absorption, using GastroPlus were evaluated.Results Spheroid formulations with similar drug composition exhibited excellent flowability. Dissolution studies revealed that the release profiles of prednisolone acetate from the produced formulations differ significantly when compared to the pure substance dissolution profile. In silico model predicted the highest absorption rate in the cecum and the ascending colon.Conclusion Spheroids derived from sodium alginate have demonstrated the ability to provide prolonged release of prednisolone acetate. Sodium alginate concentration and needle diameter were identified as key formulation factors; their increase enhanced the spheroid resistance to the simulated experimental conditions.