Poly [D,L-lactide-co-glycolide (PLGA)] 7525 7E (lactide/glycolide ratio, 75/25; molecular weight, 113,000 Da; inherent viscosity, 0.74 dl/g) was obtained from Lakeshore Biomaterials, Inc. (Birmingham, AL, USA). Butyl stearate was purchased from TCI Shanghai Development Co., Ltd. (Shanghai, China). Methylene dichloride was purchased from Beijing Chemical Works (Beijing China), and polyvinyl alcohol (PVA; Mw 13,000–23,000) was supplied by Sigma-Aldrich (Merck KGaA, Darmstadt, Germany). Isoperidone was synthesized in our laboratory. Sodium-dodecyl sulphate (SDS) was purchased from Baotaike Bio-Technology Co., Ltd, Shenyang, China.
Healthy female beagle dogs aged 1–2 years and weighing 12±2 kg were supplied by Yadong Laboratory Animal Research Center (Nanjing, China). The animals were kept in iron cages at 20±4°C, with 45–65% relative humidity and a 12 h light/dark cycle. They were fed with granulated feed and had free access to water. All animal experiments were approved by Institutional Animal Care and Use Committee of Jilin University (Changchun, China).
Healthy female beagle dogs aged 1–2 years and weighing 12±2 kg were supplied by Yadong Laboratory Animal Research Center (Nanjing, China). The animals were kept in iron cages at 20±4°C, with 45–65% relative humidity and a 12 h light/dark cycle. They were fed with granulated feed and had free access to water. All animal experiments were approved by Institutional Animal Care and Use Committee of Jilin University (Changchun, China).