Formulation and evaluation of solid lipid nanoparticles of naringin to enhance its bioavailability

The objective of the present work was to formulate solid lipid nanoparticles loaded with naringin for improving the bioavailability of naringin. The SLNs loaded with naringin were prepared by using different ratio of palmitic and stearic acid as the lipids and Tween 80 as the surfactant. The method nanoprecipitation was used for preparation of the SLNs. The surfactant (Tween 80) helps in steric stabilization of the SLNs. The size range of SLNs obtained on sonicating for 7 was found to be 429 ± 76 nm when stearic acid was used and 365 ± 28 nm when palmitic acid was used for the preparation of SLNs. The zeta potential of all the SLNs ranged from -16 to -27 mV suggesting a stable formulation. The percentage of drug incorporated during nanoparticle preparation was determined by centrifuging the drug loaded nanoparticles at 15,000 rpm for 15 min and separating the supernatant. The highest encapsulation of naringin (71.7 ± 8.6 %) was obtained when the concentration of palmitic acid was 0.14 mmol. The in vitro release of naringin from the SLNs was measured by dialysis method using simulated gastric fluid as the dissolution medium. In vitro release kinetics studies for naringin loaded SLNs exhibited a sustained release pattern. Sustained release was observed over a period of 3 days. The stability of NSLN-7 was studied by storing at 4 ± 1 °C for 30 days. The particle size remained stable at the end of the study with drug entrapment of 71.5 %. This suggests that the SLNs prepared are stable on storage.