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Diss Factsheets

Toxicological information

Additional toxicological data

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Administrative data

additional toxicological information
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11-04-2001 to 09-05-2001
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
no guideline available
Principles of method if other than guideline:
To evaluate the esophageal irritation potential of an oral buffered formulation of
alendronate sodium following weekly esophageal infusion for 4 weeks.
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
Cas Number:
Molecular formula:
C4H12NaNO7P2 · 3 H2O
Test material form:
solid: particulate/powder

Results and discussion

Any other information on results incl. tables


1. Mortality, Physical Signs, Body Weight, and Food Consumption

All dogs survived to the termination of the experiment.  There were no

treatment-related physical signs.  Emesis was seen in some drug-treated dogs

during the recovery from anesthesia.  This was not considered related to drug

treatment.  There were no drug-related effects on body weight or food


2. Gross and Light Microscopic Changes

There were no drug-related gross or light microscopic changes in the esophagi

of dogs exposed weekly to the oral buffered formulation of alendronate sodium at

a concentration of 3.73 mg/mL.  In contrast, there was gross and/or histologic

evidence of esophageal irritation in dogs infused at the highest concentration

(7.47 mg/mL); at necropsy, in 2 dogs, there was focal reddening of the distal

esophageal mucosa and histologically there was very slight to moderate

esophagitis (erosive or ulcerative) in all dogs.


This study has demonstrated that the oral buffered formulation of alendronate sodium, at a concentration of 3.73 mg/mL, is not irritating to the esophageal mucosa in dogs. At the highest concentration (7.47 mg/mL) studied, there was gross and light microscopic evidence of esophageal irritation in dogs after weekly exposure for 4 weeks.

Applicant's summary and conclusion

There were no drug-related antemortem changes in dogs. In dogs infused with 3.73 mg/mL,
there was no gross or light microscopic evidence of esophageal irritation. At a higher
concentration (7.47 mg/mL), esophagitis (erosive or ulcerative) was evident in all dogs.
This finding is relevant for classification of the substance as a respiratory irritant using the criteria set out in the Classificaiton, Labelling and Packaging Regulations 1272/2008/EC.