Ketorolac

Poly(DL-lactide-co-glycolide) (PLGA, 50:50, inherent viscosity 0.59 dL/g, MW 53.4 kDa) and poly(L-lactide) (PLA, inherent viscosity 1.16 dL/g, MW 158.0 kDa) were purchased from Durect Corporation, Birmingham, UK. Ketorolac (MW 255.27 g/mol) in the form of Ketorolac tromethamine (water solubility 200 mg/mL, log P 2.1 [22 ]) was obtained from Cayman Chemical Company, Ann Arbor, MI, USA. Hyaluronic acid (300–500 kDa, Nanjing Gemsen International Co. ltd, Nanjing, China), polyvinyl alcohol (PVA, Mowiol^® 8-88, MW 67 kDa, Sigma-Aldrich Pte. Ltd., Singapore), acetone (Honeywell Burdick & Jackson, Morris Plains, NJ, USA), dichloromethane (DCM, Honeywell Burdick & Jackson, Morris Plains, NJ, USA), methanol (high-performance liquid chromatography (HPLC) grade, Honeywell Burdick & Jackson, Muskegon, MI, USA), and sterile water for irrigation (SWI, General Hospital Products. Public Co., Ltd., Pathum Thani, Thailand) were used as received.

Morphine (Hikma), ketorolac (Cayman Chemical), and gabapentin (Acros Organics) were administered in a volume of 1 μl/g body weight. Morphine (1 mg/kg, dissolved in sterile saline) was given as a subcutaneous injection while ketorolac (10 mg/kg, dissolved in sterile saline) and gabapentin (100 mg/kg, dissolved in sterile saline) were given as intraperitoneal injections. Outcomes were measured prior to drug administration and one hour after administration.

Sodium chloride (NaCl), potassium chloride (KCl), sodium phosphate dibasic (Na₂HPO₄), potassium phosphate monobasic (KH₂PO₄), and acetonitrile were all purchased from VWR International (Ville Mont-Royal, QC, Canada). Anti-polyethylene glycol antibody [PEG-B-47] was obtained from Abcam (Toronto, ON, Canada). SureBeads magnetic beads with protein A were bought from Biorad Laboratories (Mississauga, ON, Canada). Tween-20 was purchased from Fisher Scientific (Ottawa, ON, Canada). Flurbiprofen and ketorolac were obtained from Cayman Chemical Company (Ann Harbour, MI, USA).