[Study on preparation of ligustrazine ocular implant and correlation between in vivo and in vitro drug release].
OBJECTIVE
To prepare ligustrazine (TMPZ) ocular sustained-release implant, and investigate its in vitro drug release, pharmacokinetics in rabbit vitreum and in vitro correlation.


METHODS
Ligustrazine ocular sustained-release implants were prepared by micro-twin conical screw mixers with hot-melting extrusion method, with polyactic-co-glycolic acid (PLGA) as the matrix. HPLC was adopted to determine the concentration in vitreum after ligustrazine was implanted in rabbit eyes, in order to examine its in vivo sustained-release behavior, and study the correlation between in vitro and in vivo.


RESULTS
Ligustrazine implants were prepared with a drug-loading rate between 10% and 30%, which was in conformity to the pharmacopoeia in terms of the content uniformity. Its in vitro release was in conformity to the zero-order release model. With PLGA 5050, 2. 5A as a vector, ligustrazine implants with a drug-loading rate of 30% could slowly release drug for more than 3 weeks, indicating a good correlation between in vitro and in vivo release.


CONCLUSIONS
Ligustrazine ocular implants prepared with hot-melting extrusion method is practicable. Ligustrazine ocular implants release drug smoothly in rabbit vitreous vitreums, suggesting good sustained-release effect.
School of Pharmacy, Yantai University, Yantai 264005, China. weijh624@163.com
Jun-Hua
JH
Wei
Pei
P
Li
Peng-Kai
PK
Ma
Hong-Jie
HJ
Mu
Da-Quan
DQ
Chen
Kao-Xiang
KX
Sun
D000818:Animals; D001682:Biological Availability; D004343:Drug Implants; D005123:Eye; D005260:Female; D008297:Male; D011100:Polyglycolic Acid / Q000737:chemistry; D011719:Pyrazines / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D011817:Rabbits; D014822:Vitreous Body
D004343:Drug Implants; D011719:Pyrazines; D011100:Polyglycolic Acid; C017953:tetramethylpyrazine