Preparation and Characterization of Rizatriptan Benzoate Loaded Solid Lipid Nanoparticles for Brain Targeting

Solid lipid nanoparticles are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery. Due to their unique size dependent properties, lipid nanoparticles offer possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could use for targeting of drugs to brain. The intra nasal formulation of rizatriptan benzoate would offer a practical non-invasive and an alternative route of administration for rapid drug delivery to brain and to treat migraine. Solid lipid nanoparticle containing poloxamer with mucoadhesive property increases the contact time at nasal mucosa, hence improved absorption of drug. Rizatriptan loaded solid lipid nanoparticles were prepared by modified solvent diffusion method and characterized for shape, surface morphology, particle size, FTIR, DSC, X-ray diffraction studies, drug entrapment, total drug content and in vitro drug release studies. These lipid nanoparticles were spherical in shape with smooth surface and possess particles of size range from 145 to 298 nm. The maximum in vitro drug release was found to be 91% in 8hr, drug content was between 35-45% and maximum entrapment efficiency was 80%. In vivo studies were carried out on wistar rats and the estimation of rizatriptan benzoate was performed in cerebrospinal fluid and in blood and was conceived by HPLC method. Optimized formulation of solid lipid nano particles was given intranasally and compared with I.V and oral rote with equivalent dose. The optimized nasal SLN showed values of Cmax 473.56 ng/ml, Tmax 1hr, AUC 3706.95ng/ml and T1/2 was 5.7hr, that are more superior than marketed oral formulation and drug solutions given by iv route. Rizatriptan benzoate formulated as solid lipid nanoparticles for nasal administration could have potential to avoid first-pass effect than oral route, thus improve bioavailability of drug and as a safe and sustained release nasal delivery system to control migraine.