Priprava i in vitro karakterizacija alginatnih nanokapsula za polagano oslobađanje testosterona

Slow release testosterone-loaded nanocapsules in alginate, biodegradable hydropolymer, were prepared by in situ nanoemulsion-polymer crosslinking approach. Different formulations varying in the drug loading solvent phase were prepared. Four different drug-loading solvents were assayed and the food grade hexane provided nanocapsules testosterone load of 30%. Testosterone loading was confirmed by FT-IR, DSC and quantitated by HPLC. Prepared nanocapsules appeared spherical with a dense drug core in transmission electron microscopy studies. Hydrodynamic diameter of nanocapsules was 34.5 ± 1.7 nm, with a Gaussian distribution and the zeta potential –5.0 meV. Sustained diffusive drug release was observed in vitro, following zero order kinetics releasing the drug payload over a period of 48 hours. Embedding testosterone in alginate provided sustained release. Different drug loading solvents have distinct influence on drug loading and nanocapsules size distribution. The nanocapsulation technique developed can be a good choice for the development of different sustained steroid hormonal drug carriers.U radu je opisana priprava nanokapsula za polagano oslobađanje testosterona. Nanokapsule su pripravljene iz biorazgradljivog hidrofilnog polimera alginata umrežavanjem in situ. Varirajući udio lijeka u tekućoj fazi pripravljeno je nekoliko različitih nanokapsula. Upotreba heksana kao otapala omogućila je visoki sadržaj testosterona u nanokapsulama (30%). Prisutnost testosterona potvrđena je pomoću FT-IR i DSC, a za kvantitativno određivanje upotrebljena je HPLC metoda. Pomoću transmisijskog elektronskog mikroskopa utvrđeno je da su pripravljene nanokapsule sferno simetrične i imaju gustu ovojnicu s ljekovitom supstancijom. Hidrodinamički promjer nanokapsula bio je 34,5 ± 1,7 nm (Gaussova raspodjela), a zeta potencijal –5,0 meV. Oslobađanje testosterona in vitro bilo je polagano tijekom 48 sati, a slijedilo je kinetiku nultog reda. Otapalo koje je upotrebljeno za punjenje nanokapsula ljekovitom tvari utječe na količinu ljekovite tvari i raspodjelu veličine nanokapsula. Opisana metoda nanokapsuliranja može se primijeniti i na druge steroidne hormone