ABSTRACT

The present study reports a DSC investigation of solid liquid equilibria in the o-acetylsalicylic acid caffeine binary system revealing a simple eutectic behaviour. The eutectic temperature and temperatures of liquidus were determined. Further, assessed eutectic and liquidus temperatures together with the data for pure components were used for the evaluation of the Redlich Kister equation parameters for the excess Gibbs energy of binary melts. The binary T x phase diagram of the above mentioned system was calculated using the FactSage software and the ternary eutectic in the system o-acetylsalicylic acid caffeine paracetamol was predicted.

Compounds

#	Formula	Name
1	C9H8O4	2-acetoxybenzoic acid
2	C8H10N4O2	caffeine
3	C7H6O2	benzoic acid

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	2	Triple point temperature, K ; Crystal 2			Crystal 2 Crystal 1 Air at 1 atmosphere	DSC	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2			Crystal 2 Crystal 1 Air at 1 atmosphere	DSC	1
POMD	2	Normal melting temperature, K ; Crystal 1			Crystal 1 Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Crystal 1			Crystal 1 Liquid Air at 1 atmosphere	DSC	1
POMD	3	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	3	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	1 2	Eutectic temperature, K ; Crystal - 1			Crystal - 1 Crystal - 2 Liquid Air at 1 atmosphere	DTA	1
POMD	1 2	Solid-liquid equilibrium temperature, K ; Liquid	Mole fraction - 2; Liquid	Pressure, kPa; Liquid	Liquid Crystal - 1	DTA	7
POMD	1 2	Solid-liquid equilibrium temperature, K ; Liquid	Mole fraction - 2; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 2	DTA	11

Thermodynamics Research Center / ThermoML | Thermochimica Acta

DSC study of the system o-acetylsalicylic acid-caffeine and thermodynamic modelling of the system o-acetylsalicylic acid-caffeine-paracetamol

Kouskov, L., Leitner, J.

ABSTRACT