Nanonisering

Nanonisering, or nanonization, is the process of reducing the particle size of a substance to the nanometer scale, often yielding nanocrystals or nanosuspensions. The approach can alter properties such as solubility, dissolution rate, bioavailability, stability, and color.

Methods fall into two broad categories: top-down and bottom-up. Top-down approaches physically break down larger particles, with wet media milling, pearl milling, and high-pressure homogenization being common in pharmaceuticals. Jet milling is another mechanical method. Bottom-up methods build nanoparticles from molecular precursors through precipitation or controlled crystallization, sometimes followed by stabilization.

Stabilization is crucial to prevent agglomeration. Surface-active agents, polymers, or solid supports adsorb to the particle surface to provide steric or electrostatic stabilization. Formulations may require optimization of stabilizer type, concentration, and process conditions. After production, nanosuspensions or nanocrystals may be dried via spray drying or lyophilization to form solid dosage forms or powder for handling.

Applications include pharmaceuticals, where nanosized drug particles can improve dissolution and bioavailability; pigments and coatings where nanoscale pigments provide enhanced color and brightness; cosmetics and foods seeking improved texture or delivery of active ingredients.

Advantages include increased dissolution rate and bioavailability for poorly soluble compounds, potential for improved stability and controlled release. Challenges encompass physical instability (agglomeration, Ostwald ripening), scale-up and reproducibility, and regulatory considerations for nanomaterials and their safety assessment.