ABSTRACT

In this work, two different polymorphs (form 1 and form 2) of glycolide were successfully prepared and characterized. The solubility of these two polymorphs in ethyl acetate, 1-propanol, ethanol, 2-propanol and 1-butanol at temperatures from 278.15 K to 328.15 K under atmospheric pressure (0.1 MPa) was experimentally measured by using the isothermal gravimetrical method and correlated by the modified Apelblat model and the van t Hoff equation. For all the selected solvents, the solubility curve of form 1 crossed the solubility curve of form 2 at a transition temperature in the above temperature range. Combining the results of DSC, solubility curves and dissolution data of these two polymorphs, it was confirmed that form 1 and form 2 were enantiotropic. The dissolution thermodynamic properties of glycolide form 1 and form 2 were also calculated.

Compounds

#	Formula	Name
1	C4H4O4	1,4-dioxane-2,5-dione
2	C4H8O2	ethyl acetate
3	C3H8O	propan-1-ol
4	C3H8O	propan-2-ol
5	C2H6O	ethanol
6	C4H10O	butan-1-ol

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	Triple point temperature, K ; Crystal 2			Crystal 2 Crystal 1 Air at 1 atmosphere	DSC	1
POMD	1	Normal melting temperature, K ; Crystal 1			Crystal 1 Liquid Air at 1 atmosphere	DTA	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2			Crystal 2 Crystal 1 Air at 1 atmosphere	DSC	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal 1			Crystal 1 Liquid Air at 1 atmosphere	DSC	1
POMD	2 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 2 - 1	Gravimetric method	8
POMD	2 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 1	gravimetric method	8
POMD	3 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 2 - 1	Gravimetric method	8
POMD	3 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 1	gravimetric method	8
POMD	4 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 2 - 1	Gravimetric method	8
POMD	4 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 1	gravimetric method	8
POMD	5 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 2 - 1	Gravimetric method	8
POMD	5 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 1	gravimetric method	8
POMD	6 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 2 - 1	Gravimetric method	8
POMD	6 1	Mole fraction - 1 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid Crystal 1 - 1	gravimetric method	8

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Thermodynamic properties of enantiotropic polymorphs of glycolide

Huang, Q.[Qiaoyin], Li, Y.[Yang], Yuan, F.[Fuhong], Xiao, L.[Liping], Hao, H.[Hongxun], Wang, Y.[Yongli]

ABSTRACT