Sitagliptin-loaded solid lipid nanoparticle for controlling neuroinflammation related to Alzheimer’s disease

Aim and Background: Alzheimer’s disease (AD) is a neurological disorder that is a primary form of dementia and may contribute to about a third of the cases. It is found that increased inflammation is present in AD brains even before cognitive impairment symptoms. It is known that TNF-α is a key protein in the inflammation pathway which is mainly produced by microglia in the brain. Sitagliptin as an oral anti-diabetic drug is reported to have anti-inflammatory properties from both DPP-4 inhibition-dependent and independent pathways. Methods: SLNs were prepared by melting cetyl palmitate at 59° C and addition of sitagliptin. Meanwhile, polysorbate 80 was dispersed in water and warmed up to 59° C. Then, these two phases were mixed gradually and underwent homogenization and sonication to form sitagliptin-loaded SLNs. The obtained SLNs were tested by their various characteristics including loading, XRD, IR spectroscopy, DSC, TEM, DLS, and release profile. Results and discussion: Sitagliptin-loaded nanoparticles had a size range of about 100 nm and drug loading of about 80%. Based on the results of other tests it is observable that SLNs are stable and sitagliptin is loaded inside their structure. Moreover, SLNs can provide a long-lasting profile of sitagliptin release, which results in more efficient inhibition of neuroinflammation. Conclusion: it seems that sitagliptin-loaded SLN is a good system to deliver enough amounts of the drug to the brain in a steady manner and long time.