Aliphatic polyester terpolymers for stent coating and drug elution: effect of polymer composition on drug solubility and release.
Ring-opening terpolymerization of L-lactide (LA), -caprolactone (CL), and glycolide (GA) was performed in the presence of tin (II) 2-ethylhexanoate at 170 degrees C. Random terpolyesters with weight-average molecular weight up to 130,000 g/mol were obtained. These terpolyesters, especially those with LA:CL:GA composition of 3:1:1, provided good coating integrity following spraying onto bare metal stents. The semi-synthetic macrolide immunosuppressant, everolimus, was incorporated into the terpolyester coating, and its release from the stent was evaluated. Unlike PLLA homopolymers, which are immiscible with the drug and non-optimal for controlled release, these terpolymers gave excellent control in a screening study, by tuning terpolymer molecular weight, relative monomer ratio, and drug-to-polymer ratio. Adjusting the polymer properties to improve drug solubility (or miscibility) in the polymer coating was found beneficial to the release profile.
Chan-Seng
Delphine
D
University of Massachusetts, Amherst, MA 01003, USA.
Ranganathan
T
T
Zhang
Xiongfei
X
Tang
Yiwen
Y
Lin
Qing
Q
Kleiner
Lothar
L
Emrick
Todd
T
D016503:Drug Delivery Systems / Q000379:methods; D054855:Drug-Eluting Stents; D011091:Polyesters / Q000737:chemistry* / Q000493:pharmacokinetics*; D011108:Polymers / Q000737:chemistry* / Q000493:pharmacokinetics*; D012995:Solubility
D011091:Polyesters; D011108:Polymers