title: [Studies on preparation of sustained-release Shuxiong formulation, a traditional Chinese medicine compound recipe, using time-controlled release techniques].
abstract: OBJECTIVE
  To prepare a sustained-release formulation of traditional Chinese medicine compound recipe by adopting time-controlled release techniques.
  
  
  METHODS
  Shuxiong tablets were chosen as model drug. The prescription and technique of core tablets were formulated with selecting disintegrating time and swelling volume of core tablets in water as index. The time-controlled release tablets were prepared by adopting press-coated techniques, using PEG6000, HCO and EVA as coating materials. The influences of compositions, preparation process and dissolution conditions in vitro on the lag time (T(lag)) of drug release were investigated.
  
  
  RESULTS
  The composition of core tablets was as follow: 30% of drug, 50% MCC and 20% CMS-Na. The T(lag) of time-controlled release tablets was altered remarkably by PEG6000 content of the outer layer, the amount of outer layer and hardness of tablet. The viscosity of dissolution media and basket rotation had less influence on the T(lag) but more on rate of drug release.
  
  
  CONCLUSIONS
  The core tablets pressed with the optimized composition had preferable swelling and disintegrating properties. The shuxiong sustained-release formulations which contained core tablet and two kinds of time-controlled release tablets with 3 h and 6 h of T(lag) could release drug successively at 0 h, 3 h and 6 h in vitro. The technique made it possible that various components with extremely different physicochemical properties in these preparations could release synchronously.
authors.affiliation: Department of Pharmacy, Fuzhou General Hospital of Nanjing Military Region, Fuzhou 350025, China. sohoto@sohu.com
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Song
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Chen
authors.forename: Zhong-Gui
authors.initials: ZG
authors.lastname: He
mesh_terms: D031187:Carthamus tinctorius / Q000737:chemistry; D002368:Castor Oil / Q000031:analogs & derivatives; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D004339:Drug Compounding / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D030004:Ligusticum / Q000737:chemistry; D053723:Panax notoginseng / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D011092:Polyethylene Glycols; D011205:Povidone / Q000031:analogs & derivatives; D013607:Tablets
chemical_list: D003692:Delayed-Action Preparations; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal; D013607:Tablets; C077842:polyvinylpolypyrrolidone; D011092:Polyethylene Glycols; C023040:polyethoxylated castor oil; D002368:Castor Oil; D011205:Povidone