ABSTRACT
<p><b>OBJECTIVE</b>To prepare ligustrazine (TMPZ) ocular sustained-release implant, and investigate its in vitro drug release, pharmacokinetics in rabbit vitreum and in vitro correlation.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>