Evaluation of cilazapril release profiles with the use of lignin-based spherical particles

The main focus of this study is the preparation of lignin-based spherical particles as drug delivery systems. First, particles were prepared with the use of kraft lignin and the cationic surfactant hexadecyl (trimethyl)ammonium bromide (CTAB), and their physicochemical and structural characteristics were also determined. It was observed that the particles had a spherical shape and a low polydispersity index (PdI). The lignin particles were combined with the active compound cilazapril (CIL), and the system was tested for its drug-releasing ability. Cilazapril was combined with kraft lignin or lignin-based spherical particles to prepare different formulations. Mixtures with cilazapril as a reference (CIL-DB), kraft lignin (LIG-DB) and lignin-based spheres (LC-DB) were prepared with the use of a liquid base to obtain suspensions. The dialysis bag method was employed for the evaluation of drug release profiles. Release tests were performed at three pH values: 2.0, 5.8 and 6.8. It was observed that the lignin-based material is pH-sensitive, and better results were obtained at low or high pH values. The LC-DB formulation exhibited the best dissolution rates in all pH ranges. At pH 2.0, 5.8 and 6.8 the maximum release of cilazapril was around 80%, 62% and 90%, respectively. Lignin-based spherical particles enabled more efficient, sustainable and controlled release of cilazapril and may therefore have a potential for use in the medical industry, especially in drug delivery systems.