OBJECTIVE To prepare enteric microspheres containing thymosin, and evaluate its in vitro release profiles and in vivo bioactivity. METHODS Thymosin-loaded enteric microspheres were prepared by modified oil-in-oil(O/O)emulsion solvent evaporation method, acrylic acid resin Ⅱ was used as carrier material. The effects of process parameters, such as initial drug feed and polymer concentration,on drug encapsulation efficiency and in vitro release profiles were investigated.After oral administration, the effect of thymosin-loaded microparticles on the immunity of hydrocortisone induced immunosuppressed mice was also examined.RESULTS Increase of initial drug feed led to a decrease in entrapment efficiency, while increasing polymer concentration resulted in an increase in drug entrapment efficiency.After adoptingoptimized preparation formulation, thymosin entrapment efficiency of 89.7% was achieved. Thymosin release from microspheres exhibited significant burst release, while increase in polymer concentration and reduction in drug loading decreased burst release. Orally administrated microspheres enhanced the E-rosette formation rate of lymphocyte in immunosuppressed mice induced by hydrocortisone.Thymosin-loaded microspheres had immuno-regulativity.CONCLUSION Modified O/O emulsion solvent evaporation method is adopted to prepare thymosin containing enteric microspheres. By optimizing preparation parameters, microspheres with higher entrapment efficiency are produced. The bioactivity of thymosin is not influenced during microsphere preparation process, and it has the ability to regulate and enhance immunity.
YNG Ju-fei;QIU Li-yn;JIN Yi;SHEN Yun-yun.
Preparation and Evaluation of Thymosin-Loaded Enteric Microspheres in vivo and in vitro[J]. Chinese Pharmaceutical Journal, 2006, 41(21): 1638-1641
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参考文献
[1] CHEN Z，WANG Z Y，CHEN S S.Basis and clinic of thymus hormane[J] .Shanghai J Immun(上海免疫学杂志)，1981，1(1)：45-53.
[2] ZHANG H S，CHAN Y S，HU J G，et al.Studies on preparation technology for oral microspheres of thymopeptide[J] .Chin Pharm(中国药房)，1999，10（2）：58-59.
[3] ZHANG H S，LIU W H，ZHANG J Z，et al.Pharmacokinetics and bioavailability of oral microspheres of thyopeptide in rat[J] .Chin J Biochem Pharm(中国生化药物杂志)，2000，21（1）：15-17.
[4] ZOU L，XIAO G M，QIAN L F，et al.Preparation and release characteristics in vitro of thymopeptide gelatin microspheres[J] .Chin Hosp Pharm J(中国医院药学杂志)，2004，24（9）：524-526.
[5] CHAW C S，YANG Y Y，LIM I J，et al. Water-soluble betamethasone-loaded poly(lactide-co-glycolide)hollow microparticles as a sustained release dosage form [J] .J Microencapsulation，2003，20(3)：349-359.
[6] LIN W J，WU T L. Modification of the initial release of a highly water-soluble drug from ethylcellulose microspheres [J] .J Microencapsulation，1999，16(5)：639-646.
[7] HE S Z，HAO X M，YUAN S H，et al.Comparison of immunological action of thymosin tablet with injection[J] .J Herbin Med Univ(哈尔滨医科大学学报)，1994，28（4）：295-296.
