THERMODYNAMICS OF PHARMACEUTICAL ACTIVE NICOTINAMIDE BASED BINARY ALLOYS

Abstract

The solid-liquid equilibrium data of Nicotinamide (NA)- $ \beta $-Naphthol ($ \beta $N) and Nicotinamide(NA)- Acetanilide (ACT) systems have been determined by Thaw- melt method which suggest the formation of simple eutectics in both cases. Eutectic alloy E of NA-$ \beta $N system achieved at 65°C and 0.611 mole fraction of$ \beta $N, whereas the eutectic alloy E of NA-ACT system form at 93°C and 0.596 mole fraction of ACT. The excess thermodynamic quantities have been determined by computing heat of fusion data and activity coefficient of the component in binary mix. These values highlight the ordering, stability and structure of eutectic and non-eutectic alloys. The thermodynamic mixing functions describe about the nature of mixing of the components during alloying. The Gibb’s-Duhem equations give the graphical solution of activity, activity coefficient and partial mixing thermodynamic quantities. The thermodynamic stability factors evaluated by graphical method favour the stability of eutectic and non-eutectic alloys.