Physicochemical behavior of pharmaceutical particles and distribution of additives in tablets due to process shear and lubricant composition

Effect of magnesium stearate solid lipid nanoparticles as a lubricant on the properties of tablets by direct compression

This study discusses the lubricant properties of magnesium stearate solid lipid nanoparticles (MgSt-SLN) and their effect on the tabletability, mechanical properties, disintegration, and acetaminophen-model dissolution time of microcrystalline cellulose (MCC) tablets prepared by direct compression. The behavior of MgSt-SLN was compared to reference material (RM) to identify advantages and drawbacks. The nanoprecipitation/ion exchange method was employed to prepare the MgSt-SLN. Particle size, zeta potential, specific surface area, morphology, and true density were measured to characterize the nanosystem. The MgSt-SLN particle sizes obtained were 240 ± 5 nm with a specific surface area of 12.2 m2/g. The MCC tablets with MgSt-SLN presented a reduction greater than 20 % in their ejection force, good tabletability, higher tensile strength, lower disintegration delay, and marked differences in acetaminophen dissolution when compared to the RM. The reduced particle size of the magnesium stearate seems to offer a promising technological advantage as an efficient lubricant process that does not affect the properties of tablets.

Transient Temperature Monitoring of Pharmaceutical Tablets During Compaction Using Infrared Thermography

Manufacturing of pharmaceutical tablets from powders is always accompanied by the conversion of irreversible mechanical work of compaction into heat. The heat is generated due to friction between powder particles, particles and the die wall, plastic deformation of particles, bonding, and other irreversible processes. The resulting temperature increase potentially might have significant effects on a tablet's mechanical properties, disintegration time, and drug release. In the present work, we show that using infrared thermography as a nondestructive and noncontact process analytical technology (PAT) tool to measure the tablet's rate of cooling, in contrast to the temperature evolution, can be directly related to the tablet's thermal diffusivity. Results show the potential capabilities of this technique to discriminate and toward predicting tensile strength of tablets between same formulations produced at same compaction force but experienced different process shear conditions. Correlation of the tablet's tensile strength, relative density, and rate of cooling at regular regime with respect to different process shear is also discussed.

Evaluation of the lubricating effect of magnesium stearate and glyceryl behenate solid lipid nanoparticles in a direct compression process

The aim of this study was to develop solid lipid nanoparticles (SLN) and introduce them into a direct compression process to evaluate their lubricant properties. The study consisted of preparing glyceryl behenate SLN (Compritol® 888 ATO) by hot dispersion, and magnesium stearate SLN by a novel nanoprecipitation/ion exchange method. The ejection force was measured for nanosystems and raw materials in a formulation typically used for direct compression. The smallest particle sizes obtained were 456 nm for Compritol® 888 ATO and 330 nm for magnesium stearate. Results show that the NPs used as lubricants in a direct compression model formulation provided efficient lubrication by maintaining the lubricating properties of the system, thereby decreasing the amount of lubricant used compared to the raw material. The lubricating effect showed an increase of 15-30% for magnesium stearate and Compritol® 888 ATO, compared to the raw material at concentrations above 2%.