Preparation and Characterization of Sustained Release Matrix Tablets of Tizanidine Hydrochloride for Spinal Injuries|
Zheng, Zun-Cheng; Wang, Xiao-Yu & Du, Xiao-Jing
Purpose: To formulate matrix type sustained-release (SR) tablets of tizanidine hydrochloride (TH) for
prolonged drug release and improvement in motor activity after spinal injuries.
Methods: Matrix tablets were prepared by the wet granulation method using four polymers (hydroxyl
propyl methyl cellulose [HPMC] K 100, ethyl cellulose [EC], guar gum, and polyvinylpyrrolidone (PVP
K30) and characterized for hardness, friability, drug content, swelling, weight variation, in vitro drug
release, and in vivo motor function activity using the spinal injury rat model.
Results: All tablets showed good drug content, hardness, and other physicochemical properties. The
tablet formulations showed a percent drug release ranging from 92.54 ± 1.02 to 98.56 ± 1.26 % at the
end of 12 h. Using the spinal injury rat model, negative control had a motor activity of only 12.75 %,
while F4 (containing HPMC, EC, and PVP) and F5 (containing EC, guar gum, and PVP) had motor
activities of 62.25% and 57.5%, respectively, compared with 68.0 % for normal controls.
Conclusion: SR matrix tablets of TH showed significant improvement in motor activity in post-traumatic
spinal injury rat model.
Sustained release tablet; Spinal injuries; Matrix tablet; Tizanidine hydrochloride