Saccharomyces cerevisiae, lysate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 March 2018 to 24 March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Due to the UVCB nature of the substance and the presence of one fraction totally insoluble (cell walls) and one fraction with a very high water solubility, the water solubility of this soluble fraction was determined. Since after 2 and 3 days of agitation the carbon content decreases, only the result after 1 day of agitation was taken into account to determine the water solubility.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

version 2008

Deviations:

yes

Remarks:

Since after 2 and 3 days of agitation the carbon content decreases, only the result after 1 day of agitation was taken into account to determine the water solubility

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

Since after 2 and 3 days of agitation the carbon content decreases, only the result after 1 day of agitation was taken into account to determine the water solubility

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

104.9 mg/L

Conc. based on:

other: carbon content of the dissolved fraction

Loading of aqueous phase:

1 g/L

Incubation duration:

1 d

Temp.:

30 °C

pH:

>= 6.84 - <= 7

Details on results:

After 1 and 2 days agitation time at 30°C, the relative standard deviations of obtained data are very low, but after 3 days agitation time, the measured carbon contents in the parallel vessels show a very high RSD%. Since the conditions are not sterile, after 3 days some biological degradation activity in some flasks at 30°C may occur, so this data was not taken into consideration for the evaluation. The decreasing carbon content between day 1 and day 2 can be explained by the same phenomenon. The carbon content of the soluble fraction from Saccharomyces cerevisiae, lysate was 104.9 mg/L Carbon with 0.59 RSD% in case of preparation 1 g/L nominal loading rate, after 1 day agitation time at 30°C and 1 day re-equilibration time at 20°C.

Results of the determination of the test item concentrations (carbon content) from a saturated solution of 1 g/L loading rate

Parallel sample preparation	Measured carbon content  after 1 day (mg/L)	pH	Measured carbon content  after 2 day (mg/L)	pH	Measured carbon content  after 3 day (mg/L)	pH
1	104.3	7.00	85.6	6.84	51.3	6.88
2	105.5	6.97	83.6	6.93	87.4	6.90
3	104.8	6.98	87.6	6.90	134.6	6.85
Mean	104.9	-	85.7	-	91.1	-
RSD%	0.59	-	2.5	-	45.85	-
Mean	93.9 ± 17.4 (with 95% confidence interval)
RSD%	24.1

 

 Results of the Method Validation

Repeatability	CV% ≤ 2.5%
Linear range	10 – 100 mg carbon/ L
Limit of Quantification (LOQ)	10 mg carbon/ L
Test item nominal loading rate for the water solubility study	1 g/L

 

 

Conclusions:

The carbon content of the water soluble fraction from Saccharomyces cerevisiae, lysate was 104.9 mg carbon/L with 0.59 RSD% in case of preparation 1 g/L nominal loading rate, after 1 day agitation time at 30°C and 1 day re-equilibration time at 20°C.

Executive summary:

The water solubility of Saccharomyces cerevisiae, lysate was determined following the EU method A.6 and OECD 105, and in compliance with GLP.

Since the test item is an UVCB with no single chemical marker that can be readily analysed, the NPOC (Non Purgeable Organic Carbon) method was used. The results of preliminary tests have demonstrated that 1 g/L nominal loading rate ensures the highest measurable carbon content. So three parallel samples at the loading rate of 1 g/L were prepared and agitated at 30°C for 1, 2 and 3 days. Then the flasks were removed and re-equilibrated preferably at 20 ± 0.5°C for 1 day. The content of the vessels was centrifuged at 8500 rpm for 10 minutes, then the supernatant was filtered by 0.2 µm filter, and the organic carbon content in the clear phase was determined by TOC.

Since the carbon content decreases on day 2 and 3 with a very high variability of the carbon content analysis on Day 3, the obtained results on Day 1 are considered as the most reliable and representative of the water solubility of the soluble fraction of Saccharomyces cerevisiae, lysate.

The carbon content of the soluble fraction of Saccharomyces cerevisiae, lysate was 104.9 mg/L Carbon with 0.59 RSD% in case of preparation 1 g/L nominal loading rate, after 1 day agitation time at 30°C and 1 day re-equilibration time at 20°C.

This water solubility study is classified as acceptable, and satisfies the guideline requirements of the EU method A.6 and OECD 105.

Description of key information

The carbon content of the water soluble fraction from Saccharomyces cerevisiae, lysate was 104.9 mg Carbon /L with 0.59 RSD% in case of preparation 1 g/L nominal loading rate, after 1 day agitation time at 30°C and 1 day re-equilibration time at 20°C.

Additional information

The water solubility of Saccharomyces cerevisiae, lysate was determined following the EU method A.6 and OECD 105, and in compliance with GLP.

Since the test item is an UVCB with no single chemical marker that can be readily analysed, the NPOC (Non Purgeable Organic Carbon) method was used. The results of preliminary tests have demonstrated that 1 g/L nominal loading rate ensures the highest measurable carbon content. So three parallel samples at the loading rate of 1 g/L were prepared and agitated at 30°C for 1, 2 and 3 days. Then the flasks were removed and re-equilibrated preferably at 20 ± 0.5°C for 1 day. The content of the vessels was centrifuged at 8500 rpm for 10 minutes, then the supernatant was filtered by 0.2 µm filter, and the organic carbon content in the clear phase was determined by TOC.

Since the carbon content decreases on day 2 and 3 with a very high variability of the carbon content analysis on Day 3, the obtained results on Day 1 are considered as the most reliable and representative of the water solubility of the soluble fraction of Saccharomyces cerevisiae, lysate.

The carbon content of the soluble fraction of Saccharomyces cerevisiae, lysate was 104.9 mg/L Carbon with 0.59 RSD% in case of preparation 1 g/L nominal loading rate, after 1 day agitation time at 30°C and 1 day re-equilibration time at 20°C.