title: [Studies on combined release behaviors of versatile mini-tablets in capsule systems and fittings of their mathematical model].
abstract: OBJECTIVE
  To prepare nifedipine (NP) rapid release mini-tablet, sustained release mini-tablets, pulsed release mini-tablets and delayed-onset sustained release mini-tablets and develop multiplied pulsed drug delivery system (DDS), site-specific DDS, zero-order DDS and quick/slow DDS by various ways.
  
  
  METHODS
  Velocity-time (v-t) equation of each mini-tablet was deduced by non-linear least square model fit. The difference of combinations in v-t profiles between theoretical value and test value was compared.
  
  
  RESULTS
  According to the v-t equations, the combined release behaviors were observed directly from v-t profiles and the test values coincided with the theoretical profiles.
  
  
  CONCLUSIONS
  The programmed DDS, which consist of a variety of mini-tablets with different dosages and combinations in capsules, could be predicted by summing up the v-t equation of each tablet.
authors.affiliation: Pharmaceutical Research Institute, China Pharmaceutical University, Nanjing 210009, China. 694@xinhuanet.com
authors.forename: Ying-huan
authors.initials: YH
authors.lastname: Li
authors.forename: Jia-bi
authors.initials: JB
authors.lastname: Zhu
authors.forename: Sheng-jun
authors.initials: SJ
authors.lastname: Chen
authors.forename: Ying-jun
authors.initials: YJ
authors.lastname: Jia
mesh_terms: D002214:Capsules; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D008956:Models, Chemical; D009543:Nifedipine / Q000008:administration & dosage* / Q000737:chemistry; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry; D011205:Povidone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry; D012995:Solubility; D013213:Starch / Q000737:chemistry; D013607:Tablets
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D013607:Tablets; C077842:polyvinylpolypyrrolidone; D011092:Polyethylene Glycols; D013213:Starch; D011205:Povidone; D009543:Nifedipine