Journal of Chromatography & Separation Techniques
Open Access

Abstract

HPLC Analysis of Monomer Release from Conventionally and High Temperature High-Pressure Polymerised Urethane Dimethacrylate Intended for Biomedical Applications

Mie-leng Tang, Jean-François Nguyen, Michaël Sadoun and N Dorin Ruse

Since monomer release poses significant biocompatibility concerns, the aim of this study was to determine, using HPLC, and compare monomer release from conventionally and high-temperature high-pressure (HT/HP) polymerized urethane dimethacrylate (UDMA) for biomedical applications. Three polymers were made: a) a control, obtained by conventional thermo-polymerization of UDMA with 0.5% (w) benzoyl peroxide (BPO) as initiator; b) an experimental, obtained by HT/HP polymerization of UDMA with 0.5% (w) BPO; and c) another experimental, obtained by HT/HP polymerization of UDMA without initiator. Bar-shaped polymer specimens were immersed in HPLC-grade 75% ethanol for 1 d, 7 d, 14 d, and 28 d prior to monomer determination by HPLC with an Agilent 1260 Infinity Quaternary LC. A Poroshell 120 EC-C18 (4.6x50 mm; 2.7μm) column and elution solvent consisting of HPLC-grade 65% acetonitrile in water, with a flow rate of 1 μL/min, were used. A calibration curve was constructed using standard UDMA solutions in the range of 1x10-5 M to 1x10-7 M. The limits of detection (LOD=2.62x10-6 M) and quantification (LOQ=7.65x10-6 M) for UDMA were determined. The accuracy of the method was confirmed by standard additions. Monomer release was statistically higher in the control group at all-time intervals; the lowest release was detected in the BPO-containing HT/HP polymerized group. The results suggested that there was a significant reduction in free monomer content in HT/HP polymerized UDMA and that polymers obtained under HT/ HP conditions could be more biocompatible