Aim
Enteric microspheres were prepared to prevent the interaction of drug with gastric acid and to improve its bioavail ability. Methods The enteric microspheres with a matrix structure were s uccessfully produced using a
spherical crystallization technique. Hydroxypropyl methylcellulose phthalate (HP-55), an enteric material, was coprecipitated with the drug by salting-out effect during the preparation process. A mixture of wa ter and ethanol was chosen as a good
solvent and dichloromethane was used as a b ridging agent while 0.1 mol·L -1
sodium chloride solution was selecte d as a poor solvent. Results It is the first time to prepare microspheres by making the water-
soluble drug and water-insoluble excipient coprecipitated. In vivo test demonstrated that the drug absorption from the enteric
oleanolic acid di hemiphthalate sodium (OADHPS) microspheres was significantly prolonged compared to that with OADHPS powder after a lag-time. Furthermore, the drug bioavailabil ity was 181.6% greater than that with the OADHPS powder. Conclusion The microspheres of water soluble drug could be prep ared by using water phase replacing organic phase as poor solvent which decrease the quantity of organic solvent and benefit the environment prevention.
More abstracts about the Preparation of enteric microsphere of oleanolic acid dih emiphthalate sodium by salting-out action u