Alendronate Sodium

heavy metals limit: max.20 ppm, ph (1% solution) limit between 4.0 to 5.0 (0.5 gms in 50 ml water), 4 - amino butyric acid (by tlc) limit: max.0.5%, phosphate and phosphite (by h.p.l.c.) limit: max.0.5%, loss on drying (at 140° c to 145°c) limit: 16.1% to 17.1%, assay (on dried basis) (by h.p.l.c.) (by titration) limit: 98% to 102%