Cross-linked valerolactone copolymer implants with tailorable biodegradation, loading and in vitro release of paclitaxel.

Abstract Implantable drug delivery systems, formed from degradable and non-degradable polymers, can offer several advantages over traditional dosage forms for sustained drug delivery. The majority of degradable implant systems developed to date have been formed from poly(lactide-co-glycolide) (PLGA). However, PLGA-based systems are not suitable for delivery of all drugs given that each drug is unique in terms of physico-chemical properties and polymer-drug compatibility plays a significant role in determining a drug formulation's performance. Two novel cross-linkable δ-valerolactone-based copolymers were synthesized and used to prepare cross-linked disc-shaped implants. The manipulation of the composition of the discs and conditions used during drug loading were found to influence delivery system performance including degree of swelling, degradation, drug-loading and in vitro release. The polymeric discs resulted in no adverse effects following subcutaneous implantation in naive rats. These studies support further development of cross-linkable valerolactone matrices as implantable formulations for sustained drug delivery.