Novel microspheres based on triterpene saponins from the roots of Physospermum verticillatum (Waldst & Kit) (Apiaceae) for the improvement of gemcitabine release

Objectives This study concerns the preparation and characterization of microspheresbased on a mixture of triterpene saponins, from Physospermum verticillatum(Waldst & Kit), as a carrier for the specific release of gemcitabine.Methods Triterpene saponins were derivatized with acrylic acid. The obtainedpolymerizable product was characterized by Fourier transform infrared to confirmthe ester linkage. Then, spherical microparticles were prepared by suspensionradical copolymerization and impregnated with gemcitabine.Key findings Microspheres exhibited a mean diameter of 2.7 l. The swellingstudies showed that particles swell most at pH 6.2, typical of the tumour pathology,than at pH 7.4, miming physiological conditions. The microspheres wereloaded with gemcitabine (LE 72.2%). Their release profile showed an initial dotof around 24% and a further release for 24 h.Conclusions This carrier could be potentially release the drug in the lung, as afunction of different pHs between tumour cells and healthy, reducing thesystemic drug toxicity, allowing the reduction of the doses number, increasingthe drug half-life and eliminating the problems related to the fast clearance ofgemcitabine administration.