Prasterone

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2010

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

In the literature six polymorphs (Forms I, II, III, IV, V and VI), a ¿ hydrate (S1), two polymorphic monohydrates S2 and S3, and a methanol hemisolvate (S4) were described. In internal investigations a further monohydrate (S5), a ¿ hydrate (S6) and an unstable acetone solvate (S7) were found. The crystal structure of the forms I, II and VI as well as S1, S2, and S3 is proven by single crystal X-ray analysis. From the melting points and the related enthalpies of the forms I, II, and III Chang et al conclude that they are monotropic with form I being the most stable polymorph. It is shown that form I is thermodynamically more stable at ambient temperatures than form VI.

GLP compliance:

no

Melting / freezing pt.:

>= 148 - <= 150 °C

Melting / freezing pt.:

>= 139 - <= 141 °C

Conclusions:

Prasterone is a dimorphic organic compound. Therefore prasterone has no definite melting point. The melting point range of the different forms are 139 - 141°C and 148-150°C.

Executive summary:

The three investigated samples consist according X-ray powder diffraction of form II with small amounts of form I. The DSC traces exhibit the melting endotherm of form II followed by the recrystallization exotherm of the melt into form I and the melting endotherm of form I. The melting endotherm of form I showed a small shoulder, which indicates that probably during recrystallization in addition to form I small amounts of a further polymorph was formed. The onset-temperature of the melting endotherm of form II is between 139°C and 141°C. The onset-temperature of the melting endotherm of form I is between 148°C and 150°C.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data from peer-reviewed handbook or collection of data

Principles of method if other than guideline:

not indicated

GLP compliance:

not specified

Type of method:

other: no data

Melting / freezing pt.:

>= 140 - <= 141 °C

Remarks on result:

other: in form of needles

Melting / freezing pt.:

>= 152 - <= 153 °C

Remarks on result:

other: in form of flakes

Conclusions:

Prasterone has no definite melting point. A melting range between approx. 140 - 141°C in form of needles and 152 - 153°C in form of flakes is determined.

Reference 3

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data from peer-reviewed handbook or collection of data

Principles of method if other than guideline:

not indicated

GLP compliance:

not specified

Type of method:

other: no data

Melting / freezing pt.:

>= 140 - <= 153 °C

Remarks on result:

other: mean value

It is assumed that the reported melting point was performed at normal atmospheric pressure

Conclusions:

The mean value of the reported melting point for prasterone is 140 - 153°C.

Description of key information

Prasterone is a dimorphic organic compound. Therefore prasterone has no definite melting point. The melting point range of the different forms are 139 – 141 °C and 148-150 °C.