Green chemistry, which includes - but is not restricted to - the replacement of environmentally hazardous chemicals with safer materials, product biodegradation, and the use of catalysts and renewable resources looks to improve the safety and efficiency of polymer chemistry. In this work, ibuprofen was coupled to malic acid, a naturally-occurring, renewable acid present in fruits, via its secondary alcohol to afford ibuprofen-malic acid (Ibu-MA). Ibu-MA and a diol (e.g., 1,8-octanediol) were then polymerized via biocatalytic methods using Novozym 435 (lipase B from Candida antarctica immobilized on acrylic resin), an increasingly popular green polyesterification catalyst. This work is the first report of such a malic acid polymer with functional pendant ester groups (e.g., ibuprofen). Previously, our lab demonstrated the synthesis of ibuprofen-tartaric acid polyester, but used a metal catalyst during the polymerization; however, the lipase use allows for a more environmentally friendly methodology. Polymer molecular weight and thermal properties were determined. The polyester biodegradation was also evaluated under physiological conditions; the polymer undergoes hydrolysis to yield malic acid and ibuprofen in a sustained, controlled manner. To confirm the polymer safety, cytotoxicity studies were performed using fibroblast cells. Additionally, to ensure the structure of released ibuprofen was retained, NMR analysis was used. Using principles of green chemistry, our polyester synthetic methodology moves toward a more economical and environmentally friendly future in biomaterials and drug delivery.

Polyesters of malic acid and ibuprofen: Enzyme-catalyzed polymerization

248th National Meeting (2014)

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