Stamatakis M K, Meyer-Stout P J
West Virginia University School of Pharmacy, Morgantown, WV 26506-9520, USA.
J Ren Nutr. 1999 Apr;9(2):78-83. doi: 10.1016/s1051-2276(99)90004-3.
Vitamins have traditionally been regulated as dietary supplements and have not been required to meet the same rigorous product quality performance standards as drug products. Impaired product performance, such as failure to disintegrate and/or dissolve in the gastrointestinal tract, could limit the absorption of vitamins. Furthermore, patients with renal disease have been reported to experience a wide range in gastrointestinal pH, which could influence a product's performance. The purpose of this study was to determine the effect of pH on the in vitro disintegration of renal multivitamin supplements.
Products were studied using the United States Pharmacopeial Convention standard disintegration apparatus. Products were tested in simulated gastric fluid, neutral fluid, and intestinal fluid. Product failure was defined as two or more individual tablets or capsules failing to disintegrate completely within compendial limits.
Of 11 products tested, 4 products failed the disintegration study test in all pH conditions. Sixty-four percent of the products showed statistically significant differences in disintegration time (DT) based on pH. As pH increased, time to disintegration increased.
The DT of commercially available renal multivitamin supplements was highly variable. Poorest product performance was shown in simulated intestinal fluid. The pH significantly affected in vitro disintegration in greater than half the products tested. How this affects dissolution and in vivo performance has yet to be studied.
传统上，维生素被作为膳食补充剂进行管理，并不要求其达到与药品相同严格的产品质量性能标准。产品性能受损，如在胃肠道中无法崩解和/或溶解，可能会限制维生素的吸收。此外，据报道，肾病患者的胃肠道pH值范围较广，这可能会影响产品性能。本研究的目的是确定pH值对肾用多种维生素补充剂体外崩解的影响。
使用美国药典标准崩解仪对产品进行研究。产品在模拟胃液、中性液和肠液中进行测试。产品不合格定义为两片或两片以上的片剂或胶囊在药典规定的限度内未能完全崩解。
在测试的11种产品中，有4种产品在所有pH条件下的崩解研究测试均不合格。64%的产品根据pH值在崩解时间（DT）上显示出统计学上的显著差异。随着pH值升高，崩解时间增加。
市售肾用多种维生素补充剂的DT差异很大。在模拟肠液中产品性能最差。在所测试的一半以上产品中，pH值显著影响体外崩解。这如何影响溶解和体内性能还有待研究。
