Formulation in vitro and in vivo evaluation of SRMS-based heterolipid-templated homolipid delivery system for diclofenac sodium\

The sole objective of this work was to design successful dosage oral forms of diclofenac sodium (DiNa)-loaded solid lipid microparticles (SLM) based on solidified reverse micellar solution (SRMS). Hot homogenization technique was employed to prepare DicNa SLM using a mixture goat fat and Phospholipon (R) 90G as lipid matrix and Tween (R)-80 as mobile surfactant. Characterization based on percentage yield, morphology, particle size, zeta potential, percentage encapsulation, pH and stability of SLMs were investigated. Anti-inflammatory, gastrointestinal tract (GIT) sparing effect and pharmacokinetics were carried out in rat model after oral administration. Results showed that the SLMs were spherical and smooth. The optimized formulation (SLM-4) had particle size of 79.40 +/- 0.31 mu m, polydispersity index of 0.633 +/- 0.190, zeta potential of -63.20 +/- 0.12mV and encapsulation efficiency of 91.2 +/- 0.1% with good stability after 8months of storage. The DicNa SLM had sustained release effect with good anti-inflammatory activity. Higher and prolonged plasma DicNa concentration was shown by the SLM-4 compared to pure drug and a conventional sample. These studies demonstrate that DicNa-loaded SLM based on SRMS could be a promising oral formulation for enhanced bioavailability, pharmacologic activity and gastrointestinal sparing effect of the NSAID, DicNa.