Fine Grinding Stearic Acid With A Tight PSD

Stearic acid is widely used in oral and topical pharmaceutical formulations. It is mainly used in oral formulations such as a tablet and capsule lubricants. A coarser grade of stearic acid can dislodge from tablet surfaces during the film-coating process leaving pit marks, whereas a finer grade of stearic acid (less than 100 mesh) results in film-coated tablets having very smooth surfaces. Stearic acid is notoriously difficult to mill into the 100 micron range where it is most effective.

Starting with a relatively large infeed material (d₉₀ = 1840 micron and D[4,3] of 1190 micron) and with the aid of liquid nitrogen to control temperature, the Fine Grind F10 successfully milled the material in a single-pass to a d₉₀ of 33.579 micron, d₅₀ of 14.054 micron and d₁₀ of 3.516 micron, with a volume weighted average D[4,3] = 17.029 micron at 10 kg/hr without product build-up or accumulation on any of the F10 components.

The Quadro® Fine Grind F10 is a complete stand-alone process plant that affords benefits to the processor including savings through reduced downtime, minimal space requirements, rapid product changeover and enhanced process efficiency. Other advantages include quick disassembly for maintenance, tool change and cleaning, low power consumption as compared to traditional mills, and low noise. The Model F10 promotes uniform grinding capabilities producing higher yields on specification and has a wide tooling selection to meet all grinding requirements.