Precipitated Calcium Carbonate Nano-Microparticles: Applications in Drug Delivery

Calcium carbonate (CaCO3) is an abundant mineral that has several uses in paper [1], Portland cement [2] and steel making [3], as agricultural input for soil modification [4], and food additive in soy milk and dairy products. Due to its high biocompatibility, CaCO3 is also employed in many pharmaceutical (anti-acid, dietary supplement for child and postmenopausal women), biological (scaffolds for cellular and bacterial growth) and biomedical (bioactive material for drug delivery, base for orthodontic cements) applications [5-9]. Its particles can be found as three different polymorphs (vaterite, -CaCO3, aragonite, λ-CaCO3, and calcite, β-CaCO3) in a wide variety of size, shape and crystalline structure of different properties and characteristics. Calcite is of the most common minerals on Earth due to its thermodynamic stability. It is the main constituent of sedimentary limestone rocks and has a rhombohedra crystalline structure [10]. Aragonite (also orthorhombic) occurs in the skeletal parts of calcareous organisms [11] and in the by-products of the some denitrifying bacteria (“Bacterium calcis”, or “Pseudomonas calcis 6”[12]). Vaterite can be found in eggshells, salmon otoliths in freshwater, as component of some organism’s endoskeleton and has been observed as a constituent of salts found in bile [11,13]. Recent researchers found that vaterite is composed of a major phase of hexagonal symmetry filled with amorphous nanodomains [14]. Differently from calcite and aragonite polymorphs that have faceted crystals, vaterite particles are usually spherical or irregular [15] (Figure 1). Volume 3 Issue 2 2017