Peptide Release Behavior from in-Situ Forming Implants: Effect of Multi-walled CNT on Release Profile

Abstract

The objective was to investigate the role of multi-walled carbon nano-tube MW-CNT as a nucleating agent on the phase inversion process and its effects on the morphology of PLGA in-situ forming implants and release behavior of leuprolide acetate as a model peptide. High performance liquid chromatography (HPLC) was used to measure drug release from implant and scanning electron microscopy (SEM) was conducted to study degradation and morphology of the PLGA implant. Drug release profile showed a remarkable decrease in the first and second stage bursts and a zero-order profile in the second stage which are related to phase inversion rate and implant morphology. Addition of MW-CNT led to changes in the cross sectional morphology from short and closed channels to deep and open channels. Channel depth increased 8 times from 50 μm to 400 μm by the addition of 0.8 wt% carbon nanotubes.