Lactic acid

Storage stability and reactivity towards container material

Link to relevant study record(s)

Reference

Endpoint:

storage stability and reactivity towards container material

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Principles of method if other than guideline:

Three lots of Lactic acid 90 % were tested. One lof of Lactic acid 80 % was tested.
The samples were stored in 1L HDPE containers, resembling the commercial packaging.
The samples were stored in rooms with controlled temperature and humidity. Conditions were: 25 °C, 60 % RH and 40 °C, 75 % RH.

GLP compliance:

no

Type of method:

ambient testing

Specific details on test material used for the study:

Samples were stored for 60 months at 25 °C, or 12 months at 40 °C, and assayed for colour, concentration, pyrogenicity and concentration of several impurities at 10 timepoints during this period.

Results:

Concentration of lactic acid was completely stable during the entire storage period. All other parameters were within specifications.

Transformation products:

yes

No.:

#1

No.:

#2

Conclusions:

The stability data demonstrated that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified. Given the fact that the studies were done with products of 80 % and 90 % concentration and as the results hardly show any degradation, it is justified to extrapolate the results to products with a concentration covered by that range.

Executive summary:

The stability of lactic acid when stored under controlled conditions was established in this study. Three lots of 90 % and one lof of lactic acid 80 % was tested. The samples were stored in 1L HDPE containers, resembling the commercial packaging. The samples were stored in rooms with controlled temperature and humidity. Conditions were: 25 °C, 60 % RH and 40 °C, 75 % RH. Critical on the degradation of lactic acid are color, assay and potential degradation products. Based on the result it can be concluded that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified. Given the fact that the studies were done with a product of 80 % and 90 % concentration and as the results hardly show any degradation, it is justified to extrapolate the results to products with a concentration covered by that range.

Description of key information

The stability data demonstrate that lactic acid is very stable, both at ambient conditions and at elevated temperature. A stability period of at least 5 years is justified.