Arteaga E, Rojas A, Villaseca P, Pérez L, López J M, Rodríguez L, Campino C
Departamento de Endocrinología, Facultad di Medicina, Pontificia Universidad Católica, Santiago de Chile.
Rev Med Chil. 1996 Nov;124(11):1325-33.
Prescription of calcium supplements is a frequent practice, considering that diet is insufficient to cover daily requirements of this mineral.
To study the dissolution velocity in an acid solution, of different commercial calcium supplements.
Hydrochloric acid was added to distilled water in increasing amounts to obtain a final pH of 6.9, 3.0, 2.5, 2.0 and 1.5. Eighteen commercial calcium preparations were incubated in these solutions for 60 min and dissolution velocity was measured as the percentage of elemental calcium found in solution after this incubation period.
Calcium carbonate preparations had a pH dependent dissolution velocity, ranging from 0.67 +/- 0.8% at pH 6.9 to 77.15 +/- 17.5% at pH 1.5. Using the solution with pH 1.5, the dissolution velocity of different preparations varied widely from 56 to 100%. Calcium acetate, followed by calcium citrate and dicalcic phosphate were the salts in tablets with better dissolution velocities. Among powders and effervescent preparations, those containing calcium lactogluconate and citrate had the better dissolution velocities (95 to 115%), that were independent of the solution's pH. A studied preparation with integral bone had a very low dissolution velocity, not surpassing 33 mg of calcium per tablet.
The dissolution velocity of different calcium carbonate preparations varies greatly and, in conditions of achlorhydria, it is negligible. Calcium lactogluconate and citrate dissolution velocities are independent of the solution's pH.
鉴于饮食不足以满足人体对这种矿物质的每日需求，补钙制剂的使用十分常见。
研究不同市售补钙制剂在酸性溶液中的溶解速度。
向蒸馏水中逐量添加盐酸，以得到最终pH值为6.9、3.0、2.5、2.0和1.5的溶液。将18种市售钙制剂在这些溶液中孵育60分钟，并将溶解速度测定为孵育期后溶液中发现的元素钙的百分比。
碳酸钙制剂的溶解速度与pH值有关，范围从pH 6.9时的0.67±0.8%到pH 1.5时的77.15±17.5%。使用pH值为1.5的溶液时，不同制剂的溶解速度差异很大，从56%到100%不等。醋酸钙，其次是柠檬酸钙和磷酸氢钙，是片剂中溶解速度较好的盐类。在粉末状和泡腾制剂中，含有葡萄糖酸钙和柠檬酸钙的制剂具有较好的溶解速度（95%至115%），且与溶液的pH值无关。一种含完整骨的受试制剂溶解速度非常低，每片不超过33毫克钙。
不同碳酸钙制剂的溶解速度差异很大，在胃酸缺乏的情况下，其溶解速度可忽略不计。葡萄糖酸钙和柠檬酸钙的溶解速度与溶液的pH值无关。
