[Preparation and in vitro evaluation of tanshinone IIA pulsatile release pellets].
OBJECTIVE
To develop pulsatile release pellets using tanshinone II as model drug and evaluate their properties in vitro.


METHODS
The tanshinone II pusatile release pellets with rupturable coatings were prepared by fluid bed. Hydroxy propyl methyl cellulose (HPMC), low-substituted hydroxy propyl cellulose (L-HPC)/HPMC, and HPMC/Sureleae were used as swelling agents respectively, and aqueous ethylcellulose dispersion Surelease as the material of controlled layer. Dissolution experiments were employed to evaluate the effects of different swelling agents and weight gain of each coating layer. Cross-sections of pellets with different swelling agents were observed by scanning electron microscope (SEM). The release profiles of tanshinone II from the coated pellets were fitted into various mathematic models.


RESULTS
Pellets with HPMC or L-HPC/HPMC as swelling agents could not present a significant release lag time. However, the pellets with the mixture of HPMC and Surelease as swelling agents could. As the ratio of Surelease increased in swelling layer, the lag time could be extended. As to the controlled layer, the thicker the controlled layer, the longer the lag time could be. When the controlled layer was coated by 30%-40% weight gains, 3-5 h lag time was realized. The fitted model suggested that first order equation could explain the drug release from tanshinone II pulsatile release pellets.


CONCLUSIONS
Using HPMC/Surelease mixture as swelling agents, and Surelease as the material of controlled layer, tanshinone II pulsatile release pellets with 3-5 h lag time were successfully prepared.
Liang
Xue-dan
XD
Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
Zheng
Ying
Y
Fan
Tian-yuan
TY
D045784:Abietanes / Q000008:administration & dosage*; D000284:Administration, Oral; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000138:chemical synthesis* / Q000737:chemistry; D015195:Drug Design; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage; D007785:Lactose / Q000031:analogs & derivatives / Q000737:chemistry; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D011786:Quality Control; D013607:Tablets
D045784:Abietanes; D003692:Delayed-Action Preparations; D004365:Drugs, Chinese Herbal; D013607:Tablets; C509290:hydroxypropylmethylcellulose-lactose matrix; C021751:tanshinone; C013517:ethyl cellulose; D002482:Cellulose; D008747:Methylcellulose; D007785:Lactose