Pre-clinical Preliminary Studies On Nanostructured Lipid Carriers For Improved Oral Bioavailability Of Fenofibrate

Objective:To design,optimize and prepare fenofibrate nanostructured lipid carrier suspensions by freeze-dried solidification with nanostructured lipid carrier drug delivery technology for improved stability.Then through systematic preclinical in vitro and in vivo evaluation methods,the feasibility and advantages of the nanostructured lipid carrier drug delivery system for improving the bioavailability of the insoluble drug fenofibrate were evaluated,and preclinical concept confirmation studies were completed.Methods:Based on the specific physicochemical properties of the model drug fenofibrate,pre-prescription evaluations and determinations of key quality attributes such as solubility were performed to establish a HPLC method for the determination of drug content and the encapsulation efficiency of the drug.On this basis,a single factor experimental design was used to prepare a fenofibrate nanostructured lipid carrier suspension by hot-melt ultrasonic dispersion and the appearance,particle size,and polydispersity of the fenofibrate nanostructured lipid carrier suspension were determined.The stability evaluation was used as the main evaluation index to conduct the formulation screening of the suspension.By investigating the effect of the ultrasonic dispersion method parameters on the particle size during the preparation process,the suspension was optimized.The suspension was then freeze-dried with the addition of the protective agent trehalose,the capsules were filled and the in vitro dissolution was measured,and the effect of the nanostructured lipid carrier formulations on drug dissolution was evaluated;dynamic light scattering and transmission electron microscopy were used.The particle size,polydispersity index,Zeta potential,and particle morphology of the nanoparticle lipid carrier suspension were determined;the crystalline characteristics of the drug in the nanostructured lipid carrier freeze-dried sample were analyzed using FTIR,differential scanning calorimetry and X-ray powder diffraction techniques.the study.Finally,the self-made fenofibrate suspension was used as a reference preparation.Male Sprague-Dawley rats were orally administered and the bioavailability of the homemade fenofibrate nanostructured lipid carrier suspension was compared.Results:The prescription composition of fenofibrate nanostructured lipid carrier suspension was determined by single-factor test.The optimal process was:weigh 50 mg of FNB,350 mg of glyceryl behenate,150 mg of Capryol90,and 50 mg of phospholipid S100.The mixture was heated to 80°C and melted to form an oil phase.Another Tween80?3%?was separately dissolved in 15 mL of distilled water to form an aqueous phase.Maintain the same temperature of the water phase and the oil phase,and pour the oil phase into the water phase under high speed stirring and stir for 15 minutes to make the primary emulsion.The colostrum was dispersed at 12000 rpm for 3 min using a high-speed shearing machine.Ultrasound was ultrasonically applied at 700 W for 10min and cooled in an ice-water bath for 30 min to obtain fenofibrate nanostructured lipid carrier.The obtained fenofibrate nanostructured lipid carrier suspension has a small particle size,a uniform distribution,and a good Zeta potential stability.The average particle size of the 3.33 mg/ml suspension used for further curing is 119.2 nm,and the PdI is 0.203.The suspension was freeze-dried with trehalose as a lyoprotectant;transmission electron microscopy results showed that the fenofibrate nanostructured lipid carrier suspension had no obvious crystal structure and was uniformly distributed in a spherical shape;FTIR showed that the fenofibrate and Excipients did not produce obvious physical and chemical interactions;DSC and X-ray powder diffraction measurements showed that the characteristic peaks of fenofibrate nanostructured lipid carrier lyophilized samples disappeared or attenuated;scanning electron microscopy results showed that fenofibrate nanostructured lipid carriers freeze-dried The sample is in an amorphous state without obvious crystal structure.The second method in the 4th part of the“Chinese Pharmacopoeia”2015 edition was used as the dissolution method for this product.The rotational speed was 100 rpm,and the dissolution medium was 500ml of a 1%SDS aqueous solution,and the fenofibrate nanostructured lipid carrier has a faster dissolution rate than the commercially available micronized preparation and the fenofibrate bulk drug;the content of fenofibrate nanostructured lipid carrier was established.The HPLC determination method of the dissolution rate and the method validation shows that the established method can rapidly and accurately analyze the quality of fenofibrate nanostructured lipid carriers;the male SD rats are used as experimental animals and the homemade fenofibrate nanoparticles.The average Cmax of the suspension of the lipid carrier and the self-made suspension was 48.77?g/L and28.60?g/L,respectively,and the average AUC?0-t?was 487.16?g·h/L and 380.39?g·h/L,respectively.There was a significant difference between the fenofibrate nanostructured lipid carrier and the self-made suspension,which greatly improved the bioavailability.Conclusion:The prepared 3.33 mg/ml fenofibrate nanostructured lipid suspension achieves solubilization of fenofibrate with an average particle size of approximately119.2 nm,a negative charge and a relatively stable suspension.Through lyophilization and solidification of the suspension,a lyophilized nanostructured lipid carrier freeze-dried sample was prepared,which improved the solubility and bioavailability of the drug,and the AUC increased to 1.28 times and the C_maxax increased to 1.7 compared with the self-made fenofibrate suspension,the T_maxax time significantly reduced,which shows significant clinical significance.In summary,the preparation of fenofibrate nanostructured lipid carrier using nanostructured lipid carrier drug delivery system has a simple preparation process and strong operability,and can effectively improve the in vitro dissolution rate and biological activity of the insoluble drug fenofibrate,which is beneficial to improve patient compliance and has potential clinical application prospects.