Liraglutide precursor

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

other: Scientific statement from Novo Nordisk A/S

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Justification for type of information:

Data on target substance is sparse. However, the data provided is supported by read-across from source substances (S3 and S4).

The target substance liraglutide precursor is a single-chain polypeptide consisting of 31 amino acids having an almost identical amino acid sequence as the human glucagon-like peptide 1 (GLP-1) that has 30 amino acids of which 29 amino acids in common with the target substance.
The target substance is a part of the active pharmaceutical ingredient: liraglutide (S1) as the liraglutide molecule has been obtained from the liraglutide precusor be the addition of a plamitoyl-ϒ-glutamate unit attached to the amino acid lysine in position 26 of the precusor.

S3 and S4 substances are somewhat larger polypeptides as consisting of 53 and 50 amino acids in the polypeptide chain.
 
Each of the amino acids in the above mentioned substances are and very polar molecules and when linked together in polypeptides the very polar nature of the polypeptides are considered as having very similar physicochemical properties irrespective whether they contain 31 (T) or 50 amino acids (S3,S4) for which physicochemical properties have been obtained. Thus, the results from physicochemical guideline testing for S3 and S4 for melting point, boiling point, flammability, self-ignition, and explosionwere identical and can be considered as representative for the target substance as well. With respect to vapour pressure the vapour pressure for single amino acids is extremely low (below 0.4 Pa) and thus, the vapour pressure for polypeptides would be expected to be even lower.
Data matrix for S1, S2, S3 and T is provided in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

other: Scientific statement by Novo Nordisk A/S

Key result

Water solubility:

> 60 g/L

Remarks on result:

other: as disolved in pure water

Key result

pH:

4.5 - 6.5

Remarks on result:

not determinable

Remarks:

insoluble

Details on results:

The water solubility as indicated in the table has been provided by Novo Nordisk (2015 + 2017)

Conclusions:

In the interval of pH 4.5-6.5 the substance can be considered as insoluble.
In pure water the solubility is above 60 g/L

Executive summary:

As the general experience with the substanse the following company data has been obtained:

In the interval of pH 4.5-6.5 the substance can be considered as insoluble.

In pure water the solubility is above 60 g/L

Such a solubility profile can be supported by read-across from the source substances

MI3 (S3) and X14DesB30 (S(4).

S3 and S4 substances are somewhat larger polypeptides as consisting of 53 and 50 amino acids in the polypeptide chain.

 

Each of the amino acids in the above mentioned substances are and very polar molecules and when linked together in polypeptides the very polar nature of the polypeptides are considered as having very similar physicochemical properties irrespective whether they contain 31 (T) or 50 amino acids (S3,S4) for which physicochemical properties have been obtained.

The water solubility of MI3 and X14DesB30 (solution) were determined by the shake flask method. The procedure conformed to EC Directive 92/69/EEC Method A6, and OECD Guideline 105 (1995). The solubility of MI3 at 20^oC in double distilled water was determined to be 393.1 mg/L±44.0 mg/L with a resultant pH of nominally 7.9. The solubility of X14DesB30 at 20^oC in double distilled water was determined to be 43 g/L at pH 3.6. However, Human insulin is insoluble in the pH range of 4.5 – 6.5, but outside this it has a solubility >10g/L.  Therefore, read-across from these substances provides support to the company data indicating:

In the interval of pH 4.5-6.5 Liraglutide precursor can be considered as insoluble.

In pure water the solubility is above 60 g/L

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000.03.16 – 2000.09.18

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

Deviation in the incubation temperature measured to be 18.6 oC instead of 19.5 to 20.5 oC as specified by the guideline. This deviation is considered to have little impact on the test results.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

Deviation in the incubation temperature measured to be 18.6 oC instead of 19.5 to 20.5 oC as specified by the guideline. This deviation is considered to have little impact on the test results.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL (MI3 solution)
- Appearance: brown paste
- Source and lot/batch No.of test material: QC202426
- Expiration date of the lot/batch: June 2004
- Purity test date: 2003-06-18
- Purity: 84% w/w (stated ny Sponsor)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Frozen below - 10°C

Key result

Water solubility:

ca. 393 mg/L

Conc. based on:

test mat. (dissolved fraction)

Incubation duration:

ca. 24 - ca. 72 h

Temp.:

30 °C

pH:

ca. 7.8 - ca. 8.06

Remarks on result:

other: Standard deviation of +/- 44 mg/mL

Calibration data is presented in the table below; the calibartion line was established linearly with 1/x weighting. 

Sequence reference	WSOL2
Slope	46441.6
Intercept	-10980.08
Correlation	0.99983
Minimum calibrant conc (µg/ml)	0.5
Maximum calibrant conc (µg/ml)	50

Analytical data is shown in the table below. The incubation bath was constant at a temperature of 18.6^oC over the test period.

Test ref	Time at 30^oC (h)	pH	Dilution factor	Peak area	MI3 conc (mg/L)
1	72	7.80	100	139980.1	325.05
2	72	7.94	100	204180.4	463.29
3	48	7.97	100	174576.7	399.55
4	48	7.97	100	168503.7	386.47
5	24	8.06	100	169386.6	388.37
6	24	8.02	100	172798.3	395.72

  

Conclusions:

The water solubility of MI3 (solution) was determined by the shake flask method. The procedure conformed to EC Directive 92/69/EEC Method A6, and OECD Guideline 105 (1995). The solubility of MI3 at 20 oC in double distilled water was determined to be 393.1 mg/L ± 44.0 mg/L with a resultant pH of nominally 7.9.

Executive summary:

The water solubility of MI3 (solution) was determined by the shake flask method. The procedure conformed to EC Directive 92/69/EEC Method A6, and OECD Guideline 105 (1995). The solubility of MI3 at 20^oC in double distilled water was determined to be 393.1 mg/L±44.0 mg/L with a resultant pH of nominally 7.9. This is equivalent to a CV of 11.2%, which is within the recommended limit (±15 %), and therefore considered acceptable especially when keeping in mind that the incubation bath temperature of 18.6^oC, was outside the specified temperature of 20^oC±0.5^oC.

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000.03.10 - 2000.09.21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: miscibility test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL (X14desB30)
- Appearance: Brown solid when frozen, brown paste when thawed.
- Source and lot/batch No.of test material: X14ISO201014
- Expiration date of the lot/batch: NA
- Purity test date: 2000-02-18
- Purity: 155 mg/g Active Ingredient (stated by sponsor)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Stored < - 10 degree celcius.

Key result

Water solubility:

ca. 43 - ca. 56.17 g/L

Conc. based on:

test mat. (total fraction)

Temp.:

20 °C

pH:

ca. 3.6

Conclusions:

Determination of the water solubility of X14desB30 was performed using a miscibility test in accordance to OECD guideline 105 (1995). The solubility of X14DesB30 at 20oC in double distilled water was evaluated to be 43 g/L at pH 3.6.

Executive summary:

Determination of the water solubility of X14desB30 was performed in accordance to OECD guideline 105 (1995) and EC Directive 92/69/EEC Methods A6. The test substance was inhomogeneous in suspension in water, hence the flask method and column elution method was not applicable and a miscibility test was performed. The solubility of X14DesB30 at 20^oC in double distilled water was evaluated to be 43 g/L at pH 3.6.

Description of key information

As the general experience with the substanse the following company data has been optained:

In the interval of pH 4.5-6.5 the substance can be considered as insoluble.

In pure water the solubility is above 60 g/L

Such a solubility profile can be supported by read-across from the source substances

MI3 (S3) and X14DesB30 (S(4).

S3 and S4 substances are somewhat larger polypeptides as consisting of 53 and 50 amino acids in the polypeptide chain.

 

Each of the amino acids in the above mentioned substances are and very polar molecules and when linked together in polypeptides the very polar nature of the polypeptides are considered as having very similar physicochemical properties irrespective whether they contain 31 (T) or 50 amino acids (S3,S4) for which physicochemical properties have been obtained.

The water solubility of MI3 and X14DesB30 (solution) were determined by the shake flask method. The procedure conformed to EC Directive 92/69/EEC Method A6, and OECD Guideline 105 (1995). The solubility of MI3 at 20^oC in double distilled water was determined to be 393.1 mg/L±44.0 mg/L with a resultant pH of nominally 7.9. The solubility of X14DesB30 at 20^oC in double distilled water was determined to be 43 g/L at pH 3.6. However, Human insulin is insoluble in the pH range of 4.5 – 6.5, but outside this it has a solubility >10g/L. Therefore, read-across from these substances provides support to the company data indicating:

In the interval of pH 4.5-6.5 Liraglutide precursor can be considered as insoluble.

In pure water the solubility is above 60 g/L.