Preparation of lanthanum carbonate formulations, in-vitroevaluation and bioactivity studies

Pınarbaşlı, O., Preparation of Lanthanum Carbonate Formulations, In-vitro Evaluation and Bioactivity Studies. Hacettepe University, Institute of Health Sciences, Doctor of Philosophy Thesis, Biopharmaceutics and Pharmacokinetics Program, Ankara, 2018. The aim of this study is to increase the dissolution rate and therefore the bioactivity of poorly water soluble or insoluble active drug substances by using micronization/nanonization processes. One of the common methods is to prepare drug microcrystals/nanocrystals by decreasing the particle size and thus, increasing the surface area for enhancement of dissolution rate and bioactivity. In our studies, lanthanum carbonate was used as a model drug, and its formulation was prepared with untreated active drug substance. In addition to that, Submicron/Micron (SM/M) Lanthanum Formulation was prepared using lanthanum carbonate having particle size in submicron range after ball milling process. Assay analysis, in-vitro dissolution and bioactivity of the formulations were investigated. Assay and in-vitro dissolution analysis were performed by complexometric titration method. Phosphate binding and equilibrium binding studies within the scope of bioactivity studies were carried out by ion chromatography. As a result of these experiments, the phosphate binding capacity and dissolution rate of SM/M Lanthanum Formulation were found to be higher than both Lanthanum Formulation and the reference product-Fosrenol® 1000 mg Sachet.