FORMULATION AND EVALUATION OF SILIBININ LOADED SOLID LIPID NANOPARTICLES FOR PERORAL USE TARGETING LOWER PART OF GASTROINTESTINAL TRACT

Objective: The aim of this study was to develop and evaluate silibinin (SIL) loaded solid lipid nanoparticles (SLN) in an attempt to increase its oral bioavailability and targeting the lower part of GI tract. Methods: Solvent emulsification-evaporation method with slight modification was used to prepare the SLNs, glyceryl monostearate (GMS), trimyristin (TM), tripalmitin (TP) and tristearin (TS) were investigated as solid lipid matrix. Tween 20 (T20), tween 80 (T80), polyvinyl alcohol (PVA), poloxamer 188 (P188), sodium cholate (SC) and sodium deoxycholate (SDC) were investigated as emulsifiers. The formulations were evaluated for entrapment efficiency (EE), particle size distribution and in-vitro release profile. Furthermore, the optimized formula (F2) was further investigated by TEM, FTIR and DSC studies. Results: All the prepared SLNs are within submicronal range and acceptable polydispersity index (PI). The EE of the prepared SLNs were from (64.67±4.51%) to (87.00±2.00%), GMS generally had lower EE than TGs, using P188 or PVA as coemulsifier resulted in SLNs with higher EE%. Invitro release profile show retardation follow the trend TS>TP>TM, and steric stabilizers retard the drug release more than ionic emulsifiers. FTIR and DSC studies were done for the final formula (F2) which contains TS as solid lipid matrix and T80 and P188 as emulsifier combination and it showed no drug – excipient incompatibility and suggests formation of an amorphous solid solution. Conclusion: It can be concluded that SIL could easily incorporated into SLN containing TS and P188 for oral use.