title: In vivo evaluation of risperidone-SAIB in situ system as a sustained release delivery system in rats.
abstract: The objective of this study was to evaluate a sustained release sucrose acetate isobutyrate (SAIB) in situ system formulation of risperidone (RSP) in vivo. The formulation contained SAIB, ethanol, and polylactic acid (PLA) as a release regulator. In vivo pharmacokinetics (PK) studies have shown that PLA is effective in reducing the burst effect. After a 12.5mg/kg IM injection of a 25mg/g RSP-SAIB in situ system, the C(max) was markedly reduced from 944.1+/-80.2 to 330.4+/-33.6ng/ml by increasing PLA from 1% to 10% (w/w), the T(max) were prolonged from 2 to 4.3+/-2.0h, and the area under the curve from day 0 to 2 (AUC(0-2day)) was reduced significantly from 16294.8+/-3946.4 to 7025.3+/-1979.2ngh/ml. For the RSP-SAIB in situ system including 10% PLA, the high release rates over a short period allowed therapeutic plasma concentrations to be achieved in the initial stages after activation, and sustained release of the drug led to a stable plasma concentration (by day 25, the plasma concentration was 8% of the C(max)). These initial in vivo studies suggest that RSP-SAIB in situ system is effective as a sustained delivery system.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, People's Republic of China.
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Lu
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
authors.forename: Yue
authors.initials: Y
authors.lastname: Cui
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.forename: Xiumei
authors.initials: X
authors.lastname: Lu
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019540:Area Under Curve; D003692:Delayed-Action Preparations; D008297:Male; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D018967:Risperidone / Q000008:administration & dosage* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity
chemical_list: D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D018967:Risperidone