Fadda Hala M, McConnell Emma L, Short Michael D, Basit Abdul W
Department of Pharmaceutics, The School of Pharmacy, University of London, 29-39 Brunswick Square, London, WC1N 1AX, UK.
Pharm Res. 2009 Feb;26(2):356-60. doi: 10.1007/s11095-008-9749-2. Epub 2008 Nov 4.
The transit of dosage forms through the small intestine is considered to be constant at around 3 h, and unaffected by the presence of food. Here we address this assumption and examine how the timing of tablet and food administration can influence small intestine transit time.
A non-disintegrating, radiolabelled tablet was given to ten healthy volunteers in a three-way crossover study using three different feeding regimens (1) fasted (tablet administered on an empty stomach and food withheld for four hours) (2) fed (tablet administered after food) and (3) pre-feed (tablet administered 45 min before food). Tablet transit through the gastrointestinal tract was followed using gamma scintigraphy.
The small intestinal transit times of tablets after fasted and fed dosing regimens were similar, median 204 and 210 min respectively. With the pre-feed dose, small intestinal transit time was significantly shorter than in the fasted or fed state at 141 min. With this dosing regimen, in six of the volunteers tablets were in the upper small intestine when food arrived and these had a median small intestinal transit time of 100 min.
The timing of food ingestion has a clear effect on small intestinal transit of single-unit formulations and this has implications for drug bioavailability.
剂型在小肠中的通过时间被认为在3小时左右恒定，且不受食物存在的影响。在此我们探讨这一假设，并研究片剂与食物给药时间如何影响小肠通过时间。
在一项三交叉研究中，给10名健康志愿者服用一片不崩解的放射性标记片剂，采用三种不同的进食方案：(1)禁食（空腹服用片剂，禁食4小时）；(2)进食后（进食后服用片剂）；(3)进食前（进食前45分钟服用片剂）。通过γ闪烁扫描法追踪片剂在胃肠道中的通过情况。
禁食和进食后给药方案下片剂的小肠通过时间相似，中位数分别为204分钟和210分钟。进食前给药时，小肠通过时间显著短于禁食或进食后状态，为141分钟。采用这种给药方案，6名志愿者在食物到达时片剂位于小肠上段，这些片剂的小肠通过时间中位数为100分钟。
进食时间对单剂量制剂的小肠通过有明显影响，这对药物生物利用度有重要意义。
