title: A Uniform Ultra-Small Microsphere/SAIB Hybrid Depot with Low Burst Release for Long-Term Continuous Drug Release.
abstract: OBJECTIVE
  In the present study, a uniform ultra-small microsphere/sucrose acetate isobutyrate (SAIB) hybrid depot (m-SAIB depot) was designed to provide a long-term sustained release drug delivery system which not only reduced the burst release of an SAIB depot, but also eliminated the lag-time of PLGA microspheres.
  
  
  METHODS
  Risperidone loaded m-SAIB depot (Ris-m-SAIB depot) was characterized by in vitro drug release, pharmacokinetics, in vivo degradation and biocompatibility, in comparison with risperidone loaded SAIB depot (Ris-SAIB depot).
  
  
  RESULTS
  Ris-m-SAIB depot showed a low burst release (0.64%) and a reduced in vitro drug release rate due to the encapsulation of most drug in microspheres. After intramuscular administration, the in vivo burst release of Ris-m-SAIB was significantly decreased, as reflected by the low Cmax/Cs(4-td) (approximately 30-fold reduction), in comparison with Ris-SAIB depot. From 4 to 78 days, Ris-m-SAIB depot showed a higher plasma drug level (1.55 ~ 16.30 ng/ml) with a steadier drug release profile compared with Ris-SAIB depot. Ris-m-SAIB depot degraded gradually with a degradation t1/2 of 54.6 days and exhibited good biocompatibility in vivo.
  
  
  CONCLUSIONS
  These results demonstrate the potential application of a uniform ultra-small microsphere/SAIB hybrid depot for continuously delivering small drug molecules for long periods of time without burst release.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China. 13840485982@163.com.|School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, People's Republic of China. 13840485982@163.com.
authors.forename: Xia
authors.initials: X
authors.lastname: Lin
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Pharmaceutics Science, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
authors.affiliation: Normal College, Shenyang University, Shenyang, 110044, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutics Science, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics Science, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, People's Republic of China.
authors.forename: Haibing
authors.initials: H
authors.lastname: He
authors.affiliation: School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, People's Republic of China. ziggyyang@163.com.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Yang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding; D065546:Drug Liberation; D008863:Microspheres; D008962:Models, Theoretical; D010316:Particle Size; D018967:Risperidone / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D013395:Sucrose / Q000031:analogs & derivatives* / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D013395:Sucrose; C002885:sucrose acetate isobutyrate; D018967:Risperidone
keywords: biocompatibility; burst release; continuous drug release; degradation in vivo; uniform ultra-small microsphere/SAIB hybrid depot