title: Disintegration/dissolution profiles of copies of Fosamax (alendronate).
abstract: OBJECTIVE
  Poor quality has been reported for some generics and other copies of original products. We performed a pilot study to compare the disintegration/dissolution profiles of FOSAMAX (alendronate) 70 mg tablets with those of copies of FOSAMAX that were manufactured outside the United States.
  
  
  METHODS
  We used the standard United States Pharmacopeia (USP) disintegration method to evaluate FOSAMAX 70 mg tablets and 13 copies. At least 12 (n = 12) dosage units were tested for each product (except Fosmin, n = 10). The dissolution profiles of FOSAMAX and one representative copy were also compared.
  
  
  RESULTS
  Nine copies (Osteomax, Defixal, Fosmin, Endronax, Osteomix, Genalmen, Fixopan, Osteoplus, and Fosval) disintegrated two- to ten-fold faster than FOSAMAX. Three other copies (Neobon, Regenesis, and Ostenan) disintegrated at least five-fold slower than FOSAMAX. Neobon is a softgel capsule, so special consideration was given to this different dosage form. One copy (Arendal) did not fall into either category but exhibited potentially large inter- and intra-lot variability. Dissolution of alendronate from Regenesis lagged behind that from FOSAMAX.
  
  
  CONCLUSIONS
  Slower disintegration may reduce efficacy because bisphosphonates must be taken in the fasting state and contact with food or even certain beverages severely reduces bioavailability. Faster disintegration (or the use of gel-caps or other alterations to the drug formulation) could increase the risk of esophagitis, an adverse event associated with prolonged contact of the esophagus with bisphosphonates. These disintegration and dissolution results suggest that important differences may exist between FOSAMAX and its copies with regard to bioavailability, pharmacokinetics, and clinical efficacy and safety profiles. Additional testing is warranted to evaluate the pharmacokinetics and clinical safety of these copies.
authors.affiliation: Mount Sinai School of Medicine, New York, NY, USA. bonedocsol@aol.com
authors.forename: S
authors.initials: S
authors.lastname: Epstein
authors.forename: B
authors.initials: B
authors.lastname: Cryer
authors.forename: S
authors.initials: S
authors.lastname: Ragi
authors.forename: J R
authors.initials: JR
authors.lastname: Zanchetta
authors.forename: J
authors.initials: J
authors.lastname: Walliser
authors.forename: J
authors.initials: J
authors.lastname: Chow
authors.forename: M A
authors.initials: MA
authors.lastname: Johnson
authors.forename: A E
authors.initials: AE
authors.lastname: Leyes
mesh_terms: D019386:Alendronate / Q000737:chemistry / Q000493:pharmacokinetics*; D001682:Biological Availability; D016568:Drugs, Generic / Q000737:chemistry / Q000493:pharmacokinetics*; D004941:Esophagitis / Q000209:etiology; D006801:Humans; D007843:Latin America; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy; D010865:Pilot Projects; D012449:Safety; D012995:Solubility; D013607:Tablets; D013810:Therapeutic Equivalency; D014867:Water / Q000737:chemistry
chemical_list: D016568:Drugs, Generic; D013607:Tablets; D014867:Water; D019386:Alendronate