Ambrogi Valeria
Department of Pharmaceutical Sciences, Via del Liceo 1, 06123 Perugia, Italy.
Pharmaceutics. 2023 Jan 16;15(1):300. doi: 10.3390/pharmaceutics15010300.
Calcium carbonate is an excipient traditionally used in solid dosage forms with several functions such as a diluent, a quick dissolution agent, a buffer and an opacifier. Recently, many other challenges have arisen for calcium carbonate and, among them, the possibility of using it as an excipient for improving the dissolution rate of poorly soluble drugs. As a consequence of their poor solubility in biological fluids, many active ingredients suffer from low and erratic bioavailability when administered by the oral route and thus, many formulation strategies and excipients have been proposed to overcome this problem. Among them, calcium carbonate has been proposed as an excipient for improving dissolution rates. Calcium carbonate has many interesting characteristics, in fact it dissolves quickly in gastric fluid, is inexpensive and is safe. It exists in different polymorphic forms and in porous morphology and recently a porous functionalized calcium carbonate has been proposed as a new excipient. This review is the first overview on the use of calcium carbonate as an excipient for improving drug dissolution rates. The drug loading procedure, the physical characterization of the drug/CaCO samples and their dissolution profiles will be described. Moreover, the possible mechanisms of dissolution improvement, such as the presence of the drug in amorphous or polymorphic forms, in small crystals, and the effects of CaCO dissolution in acidic medium will be discussed. Different polymorphic forms of calcium carbonate and the presence of porosity and functionalization will be analyzed as well and their effects on dissolution rates will be discussed.
碳酸钙是传统上用于固体剂型的辅料，具有多种功能，如稀释剂、速溶剂、缓冲剂和遮光剂。最近，碳酸钙面临了许多其他挑战，其中包括将其用作提高难溶性药物溶出速率的辅料的可能性。由于许多活性成分在生物流体中的溶解度较差，口服给药时生物利用度低且不稳定，因此人们提出了许多制剂策略和辅料来克服这一问题。其中，碳酸钙已被提议作为提高溶出速率的辅料。碳酸钙具有许多有趣的特性，事实上它在胃液中溶解迅速、价格低廉且安全。它以不同的多晶型形式存在且具有多孔形态，最近一种多孔功能化碳酸钙已被提议作为一种新型辅料。本综述首次概述了碳酸钙作为提高药物溶出速率的辅料的应用。将描述药物负载过程、药物/碳酸钙样品的物理表征及其溶出曲线。此外，还将讨论溶出改善的可能机制，如药物以无定形或多晶型形式、小晶体形式存在，以及碳酸钙在酸性介质中溶解的影响。还将分析碳酸钙的不同多晶型形式以及孔隙率和功能化的存在，并讨论它们对溶出速率的影响。
