In vitro disintegration studies of weekly generic alendronate sodium tablets (70 mg) available in the US.
BACKGROUND
Bisphosphonates as a class have the potential to cause upper gastrointestinal irritation. Although the generic alendronate sodium tablets are bioequivalent to the branded product, a potential concern is that the pharmaceutical attributes of the various generic formulations my affect the potential for local irritation and tolerability.


METHODS
The in vitro disintegration times were determined using the method described in the US Pharmacopeia 30 (USP 30). The disintegration of three generic alendronate sodium tablets 70 mg available in the United States was compared to that of the branded product.


RESULTS
The mean disintegration times of the generic alendronate sodium tablets ranged from 9 to 10 s for the Barr lots to 108 s for the Watson lot. The disintegration time of the branded product (Fosamax) was 53 s. The three Barr lots and one Teva lot had rapid disintegration times which were similar to the disintegration standards (< 30 s) for orally disintegrating tablets. Since there is no established disintegration time for alendronate sodium tablets there can be no assurance that the generic tablets are equivalent to the branded product in terms of esophageal exposure. However, the in vitro disintegration times have not been correlated with in vivo disintegration performance.


CONCLUSIONS
Copies of generic alendronate sodium tablets are approved based on the results of single-dose bioavailability studies in healthy subjects and this is not considered adequate to establish similar disintegration characteristics.
Dansereau
Richard J
RJ
Procter and Gamble Pharmaceuticals, Mason, OH, USA. dansereau.rj@pg.com
Crail
Debbie J
DJ
Perkins
Alan C
AC
D019386:Alendronate / Q000737:chemistry*; D016568:Drugs, Generic / Q000737:chemistry*; D013607:Tablets / Q000737:chemistry*; D014481:United States
D016568:Drugs, Generic; D013607:Tablets; D019386:Alendronate