Gastric residence

P. Mojaverian and P. H. Vlasses, Effects of gender, posture, and age on gastric residence time of an indigestible solid Pharmaceutical considerations, Pharm. Res., 5, 639 (1988). 

Itoh, T., Higuchi, T., Gardner, C.R. and Caldwell, L. 1986. Effect of particle size and food on gastric residence time of nondisintegrating solids in beagle dogs. J. Pharm. Pharmacol. 38 801-806. 

As a result, if dissolution from formulations is studied exclusively under low pH conditions, the formulators are likely to be in for a rude shock when the results come back from the pharmacokinetic studies—poor and highly variable absorption is the order of the day for drugs that have been formulated without an eye to robustness of the release from the dosage form as a function of pH. Instead, it is recommended that a formulation be sought that can release the drug even when there is not enough acid in the stomach to provide a sufficient boost to the solubility or when the gastric residence time is short. 

Examination of the results on the basis of where the majority of pellets were situated (Table 2) shows that food increased the gastric residence time in each volunteer by 2-10 h. The entry of... 

Mojaverian P, Ferguson PK, Vlasses PH, Rood ML Jr, Oren A, Fix JA, Caldwell LJ, Gardner C. Estimation of gastric residence time of the Heidelberg capsule in humans effect of varying food composition. Gastroenterology, 1985 89 392-397. 

Thairs, S., et al. 1998. Effect of dose size, food and surface coating on the gastric residence and distribution of an ion exchange resin. Int J Pharm 176 47. 

The potential sources of variability for gastric residence in the fed mode are the size of the pyloric opening versus the tablet size, the rate of reduction in the size of the tablet by dissolution and antral grinding by the stomach, and inter- and intraindividual variations in the duration of the fed mode, particularly as a function of caloric and fat content. The dominant limitation in the use of food for gastric retention is the minimal total fat content. 

Hejazi, R., and Amiji, M. Stomach-specific anti-H. pylori therapy II. Gastric residence studies of tetracycline-loaded chitosan microspheres in gerbils. Pharm. Dev. Technol. 8 252-262, 2003. 

Mojaverian, P., Rocci, M. L., Conner, D. P., et al. Effect of food on the absorption of enteric-coated aspirin Correlation with gastric residence time. Clin. Pharmacol. Ther. 41 11-17, 1987. 

The relationship between gastric residence time (GRT) and the variability in aspirin absorption from enteric-coated tablets has also been evaluated with the Heidelberg capsule [59], The study design was a single dose crossover study with men and women, fasted and fed. In addition to pH monitoring, plasma concentrations of salicylic acid and salicyluric acid in plasma and urine were measured. GRT was significantly delayed in the fed state, and women had longer GRT compared with men. 

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