@misc{Niwiński_Krzysztof_The_2008,
 author={Niwiński, Krzysztof},
 address={Kraków},
 howpublished={online},
 year={2008},
 school={Wydział Farmaceutyczny},
 language={pol},
 abstract={The research assumptions of the study concerned an evaluation of etherderivatives of cellulose: hydroxypropylmethylcellulose (HPMC) and HPMC acetatesuccinate applications regarding pellet formulations, which are used as a staging product in preparation of tablets. Two drugs (atenolol and nifedipine) were chosen. Development of nifedipine solid dispersion technology, preparation of two types of pellets (with atenolol and with nifedipine), and tableting of pellets were taken into consideration in this study. Solid dispersion of nifedipine was prepared by co-precipitation method with simultaneous deposition on microcrystalline cellulose (MCC) particles. From over 120 formulations, 6 chosen: with atenolol and containing solid dispersion of nifedipine were undergone of physicochemical and the release studies. It was observed the improved release rate of nifedipine from pellets containing its solid dispersion. The formulation was evaluated regarding possibilities of tableting process on the basis of results from tests of hardness, friability, mass uniformity, sphericity, angle of repose and porosity, compressibility and release rate also. Two types of pellets were selected for tableting: pellets with solid dispersion of nifedipine and pellets of atenolol with lactose and MCC. The addition of silicified MCC had a protective function on tableting pellets and maintained structure of pel},
 abstract={lets. The effect of the contents of tableting pellets on the release rate of drug from tablets was demonstrated. The analyzed profiles correlated very well with Higuchi model.},
 title={The influence of cellulose derivatives on the technology of pellets tableting},
 type={Praca doktorska},
 keywords={HPCAS, nifedipine, atenolol, pellets, tableting},
}