title: [Development of sustained release tablet of tamoxifen citrate and its in vitro release profile].
abstract: OBJECTIVE
  To reduce the frequency of administration of tamoxifen citrate so as to improve its bioavailability and patients' compliance.
  
  
  METHODS
  HPMC(K4M) was employed as major retarded-release controller. The wetting granulation and directly compressing method was used to produce the sustained release tablet. Then the in vitro release profile was applied as main criteria to evaluate six formulations according to the variation of HPMC(K4M) amount. The concentration of tamoxifen citrate was measured by UV spectrometry. Finally the releasing characteristics of sustained release and conventional tablets were compared to clarify the sustained effect of the former.
  
  
  RESULTS
  At 278 nm there was no interaction between tamoxifen citrate and the recipients so that it was adopted as the wavelength of determination. The recovery efficiency of this method ranged from 95%-105%. The final formulation could release 86.40% of its loading amount in 12 h and its releasing profile fitted the Zero-order equation well. The percentages of accumulative release in 1 h were 76.81% and 7.08% for sustained release tablet and conventional tablet respectively.
  
  
  CONCLUSIONS
  The sustained release tablet of tamoxifen citrate could demonstrate a continuous and stable releasing profile and last for over 12 h. It has significant retarded effect in comparison with the conventional one and could be a new choice of regimen in its clinical application.
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100083, China.
authors.forename: Kuangshi
authors.initials: K
authors.lastname: Wu
authors.forename: Ganlin
authors.initials: G
authors.lastname: Zhao
authors.forename: Shiqin
authors.initials: S
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D003692:Delayed-Action Preparations; D012995:Solubility; D013607:Tablets; D013629:Tamoxifen / Q000008:administration & dosage* / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D013607:Tablets; D013629:Tamoxifen