A preformulation study of nicotinic acid with an emphasis on the effect of compaction and grinding on its thermal behavior

Nicotinic acid belongs to the B group of vitamins and is often referred to as Vitamin B-3 It is an essential component of a balanced diet and is prescribed as tablet, and in parenteral dosage forms in cases of vitamin deficiency. This study involves a preliminary preformulation study to assess whether nicotinic acid is a good candidate for tablet and capsule manufacture. The manufacturing process for solid dosage forms involves high energy-intensive processes, which mainly include grinding and compaction. The effect of these high-energy processes on the stability of nicotinic acid was evaluated using thermogravimetry (TG) as the primary analytical tool. The initial stage involved characterizing the thermal behavior of the material. It was found that nicotinic acid shows a solid-solid state phase transition, which is reversible. This transition appears as a small endothermic peak on the differential thermal analysis (DTA) curve, just before the dual sublimation-evaporation stage. This was followed by studying the impact of the high-energy processes on the kinetic parameters of the dual sublimation-evaporation stage. The kinetic parameters and mechanism for the two stage thermal behavior remain unaffected even after exposure to the grinding and compaction processes. This indicates that the material is a suitable candidate for formulation as a solid dosage form. In addition to this, the vapor pressure of nicotinic acid was also determined.