9Tenma T, Yodoya E, Tashima S, et al. Development of new lipophilic derivatives of tetragastrin: Physiochemical characteristics and intestinal absorption of acyl-tetragastrin derivatives in rats [J]. Pharm Res, 1993,10(10):1488-1492.
10Lee VHL, Yamamoto A. Penetration and enzymatic barriers to peptide and protein absorption [J]. Adv Drug Deliv Rev, 1990,4(2):171-207.