Extract of Boswellia serrata (Burseraceae) obtained from exudate by solvent extraction

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 September - 23 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP compliance programme (inspected on 13-14 October 2014 / signed on 8 April 2015)

Type of method:

capillary method

Remarks:

and DSC method

Key result

Melting / freezing pt.:

>= 122.2 - <= 127.2 °C

Decomposition:

ambiguous

Decomp. temp.:

ca. 99.1 °C

Results

 Pre-test for melting range following capillary method

The test item melted to a slightly yellow sticky mass between 110.1 and 120.7°C . Heating was performed up to 140 °C and the test item was more transparent.

Test for melting range following DSC method

DSC measurements showed only an endothermic increase in the heat flow at 359.53 °C. After the test the crucible was visually unchanged, the crucible was opened and a very small amount of whitely to yellow discolored residue was visible. However, no melting point/range can be determined using this method.

Finally, the determination of Melting Point was conducted using the Capillary Method.

Main test for melting range following capillary method

Melting point/range:

Melting point/range	Begin	End
First Determination	122.1 °C (395.3 K)	127.0 °C (400.2 K)
Second Determination	122.2 °C (395.4 K)	127.3 °C (400.5 K)

Observations Melting Point with the Capillary Method

Observations	First determination	Second determination	Comments
Instantly together shrivelled	99.2	99.1	Shrivel of the test item at 99 °C may be considered as a moisture, because the test item was not dried before determination or as a sign of decomposition of the substance.
Getting yellowish	119.2	119.1	The yellowish discolouring at 119 °C may be considered as a sign of decomposition and it might be a reaction of the test item because of the moisture as well.
Started to melt	122.1	122.2	The substance is not flowable at these temperatures.
Not yet together flowed- Supposed end of melting process	127.0	127.3	The substance is not flowable at these temperatures.
Together flowed	185	-	The test item had flowed together at 185 °C only, which may be due to the viscous character of the test item.
Further heating for information purpose, boiling in capillary was visible	234	-

After cooling down the test item solidified as brown mass.

 

Melting range:                         122.2 °C to 127.2 °C (395.4 K to 400.4 K) (mean of two independent determinations.

Standard deviation:                  0.07 (begin); 0.21 (end)

Estimated accuracy:                ± 0.3 °C

We noted potential degradation of the substance starting from 99.1 °C.

Validity

The“difference between duplicate determinations” was 0.3K (< 0.5K). Then the validity criterion was met.

The "difference between begin and end of melting process" was 5.0K (>0.5K). Then , the validity criterion to define a melting point was not met and a melting range was stated. As the test item is a UVCB substance, this is considered as normal.

Conclusions:

The melting range was determined as 122.2°C to 127.2 °C (395.4 K to 400.4 K) with potential degradation of the substance at about 99.1°C.
We note that the test item was flowable only at 185 °C, which can be due to the viscosity of the substance.

Executive summary:

A study was conducted under GLP according to EU Method A.1 and OECD 102 to determine the melting point /range of the substance.

Capillary pre-test and DSC measurements were performed to determine the method to be used to determine the melting point/range of the substance.

Finally two independant determinations were conducted using the capillary method and the mean values were used to determine the melting range of the substance.

Description of key information

The melting range was determined as 122.2°C to 127.2 °C (395.4 K to 400.4 K) with potential degradation of the substance starting from about 99.1 °C

We note that the test item was flowable only at 185 °C, which can be due to the viscosity of the substance.

Additional information

A fully reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines using capillary method, is available.

It is considered as a key study. The result is retained as key data.