Haematoxylin

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Principles of method if other than guideline:

Determination of the dissolution rates of Hematoxylin by gravimetric measurements
- Suspensions of circa 1g of Hematoxylin (on the other hand) were prepared in 30 mL of distillated water.
- The suspensions were stirred at 20°C during either two hours or four hours. The temperature of the suspensions was maintained constant thanks to a thermostated batch (model: Lauda RE145): 20 ± 0.5°C.
- At two (or four) hours of stirring, the stirring was stopped (decantation occurred) and homogenous solutions were sampled from the suspensions (by Pasteur pipettes and cotton filters). The solutions were placed inside vials previously tared. Three samplings were performed for every sample at the two stirring times.
- At the same time, the solid in suspension was analyzed (still humid) by XRPD to determine the nature of the solid phase which was dissolving in the liquid phase.
- The solutions were weighted, and then let under full evaporation at 50°C inside a ventilated oven.
- After full evaporation of the solvents, the dry extracts were weighted, and the dissolution rate was directly calculated.

GLP compliance:

not specified

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

Haematoxylin

EC Number:

208-237-3

EC Name:

Haematoxylin

Cas Number:

517-28-2

Molecular formula:

C16H14O6

IUPAC Name:

haematoxylin

Results and discussion

Water solubility

Key result

Water solubility:

>= 18.3 - <= 19.3 g/L

Conc. based on:

test mat. (total fraction)

Incubation duration:

>= 2 - <= 4 h

Temp.:

20 °C

Remarks on result:

other: pH not specified

Applicant's summary and conclusion

Conclusions:

Based on gravimetric method, the dissolution rates at 2h and 4h of Hematoxylin HPL were estimated respectively at: 1.80% in mass and 1.90% in mass (or circa 18.3 g/L and 19.3 g/L).

Executive summary:

Based on gravimetric method, the dissolution rates at 2h and 4h of Hematoxylin HPL were estimated respectively at: 1.80% in mass and 1.90% in mass (or circa 18.3 g/L and 19.3 g/L).