Should Magnesium Stearate be Assessed in the Formulation of Solid Dosage Forms by Weight or by Surface Area ?

Abstract

Three batches of magnesium stearate differing in morphology, particle size, bulk density and specific surface area were compared in the preparation of Pyrazinamide direct compression tablets. When the lubricants were used in the same amount they gave rise to tablets differing in hardness, disintegration and dissolution. When they were used in such amounts to develop equivalent lubricating areas, the final characteristics of the tablets were almost identical. A direct correlation was found between lubricating areas and ejection force.