Preparation Of Microencapsulated Buccal Tablets Of Ursolic Acid

Upper respiratory tract infection is a common disease,the incidence rate is very high.Ursolic acid has the pharmacological activities of anti-inflammatory,relieving cough and sterilization.Particularly,it can effectively kill the oral candida albicans.However,ursolic acid has poor aqueous solubility and low bioavailability which restrict its clinical application.The microcapsulated buccal tablets of ursolic acid prepared in this study,not only can effectively improve the solubility of ursolic acid,but also can significantly improve its bioavailability.Emulsion solvent evaporation was used as the optimal method to prepare ursolic acid microcapsules in this study.The detection method of the content of ursolic acid,the encapsulation efficiency and drug loading of ursolic acid microcapsules were established.The single-factor test,Plackett-Burman design and Box-Behnken response surface methodology(RSM)were used to screen out the optimal preparation conditions for ursolic acid microcapsules,with the particle size,particle size distribution and entrapment efficiency of microcapsules as indicators.The final parameters of the optimal technological conditions were obtained as follows:the ursolic acid 60.0 mg,the carrier material of 68%lecithin 100.0 mg and the glycerin monostearate 20.0 mg monostearin,oil phase of ethyl acetate 17.0 mL and the ethanol 13.0 mL,the aqueous phase of 0.03%Tween-40 150.0 mL,emulsion temperature 60 ?.The experimental results showed that the particle size of ursolic acid microcapsules was(148.6±12.3)nm,the polydispersity index(PDI)was 0.273,the encapsulation efficiency was(95.65±1.8)%,the drug loading was 32.35%.The analysis of UV-Vis spectrophotometry(UV),fourier transform infrared spectrophotometry(IR)and differential scanning calorimetry(DSC)showed that the molecular structure of ursolic acid did not change during the preparation process of ursolic acid microcapsules.Meanwhile,ursolic acid and the carrier material formed the stability inclusion compounds.The method of wet granulation for tablets was used to prepare the microencapsulated buccal tablets of ursolic acid.According to the pharmacological and toxicological test results of ursolic acid,the content of ursolic acid in buccal tablet was determined as(20.0±0.5)mg tablets,the tablet weight was(0.30±0.01)g.The varieties and dosage of diluents,disintegrating agents,lubricants and flavoring agents of the buccal tablets were investigated by the preliminary experiments and L9(34)orthogonal experimental design.The optimal prescription for the microencapsulated buccal tablets of ursolic acid was obtained as follows:ursolic acid microencapsulated powder 2.0 g,starch 2.0 g,microcrystalline cellulose 4.0 g,mannitol 0.5 g,lactose 0.5 g,crosslinked polyvinylpyrrolidone 0.2 g and magnesium stearate 0.3 g.In accordance with the relevant provisions of the tablet quality standards in the second appendix of the Chinese Pharmacopoeia 2010 edition,the appearance of microcapsulated buccal tablets of ursolic acid,variation for the tablet weight,hardness,frnability,disintegration,dissolution and content uniformity were studied.The test results showed that the indicators of microcapsulated buccal tablets of ursolic acid were in full compliance with the Pharmacopoeia requirements.And the dissolution of microcapsulated buccal tablets of ursolic acid was significantly higher than the conventional tablets,which was proved that microencapsulation can significantly improve the dissolution of ursolic acid,thereby increasing its bioavailability.TLC examination showed that the pharmacological compound of ursolic acid in the preparation process of the microcapsulated buccal tablets of ursolic acid did not degenerate.Thus,it was proved that the preparation process of the microcapsulated buccal tablets of ursolic acid was stable and reliable.