Abstract:
Pharmaceuticals are subject to degradation by light, heat and time. There is a danger of their passage to environment mainly the aquatic ecosystem. Five drugs (active ingredients) amoxicillin, carbamazepine, ciprofloxacin, cefradine and mefenamic acid were selected to study their photodegradation in the aqueous solution by uv-vis spectrophotometry. The separated moieties in HPLC were compared with a standard samples in sunlight and in dark conditions. The amoxicillin is found to be more stable than the other drugs. The photoproducts were identified by GC-MS to amoxicillin and carbamazepine: For amoxicillin as amoxicillin penicilloic acid (C16H21N3O6S). For carbamazepine, the degraded compounds are of molecular weights 196 and 256. Kinetic study of half-lives by equation are of the first order was reached t½ AMX 693 h, CBZ 693h, CIP 31.5h, CEF 9.24h and MEF 173h.
