metronidazole.

Metronidazole 2-(2-methyl-5-nitro-1H-imidazole-1-yl) ethanol is a synthetic nitroimidazole derivative of antibacterial and antiprotozoal activity. It has different dosage forms. The stability of the Metronidazole intravenous of three different brands was studied in order to investigate the kinetics of photodegradation of this drug using a UV/ Vis spectroscopy. The degradation was carried out by the use of short (254 nm) and long UV (352 nm) lamps. The kinetics parameters of reaction order and the rate constants of the degradation were determined for the three brands products.  The degradation process was found to follow first-order kinetics. The present study also reveals that the drug is light-sensitive. Thus, appropriate light protection is recommended during the storage and handling of metronidazole products. The study highlighted the fact that there is a correlation between the radiation intensity and degradation of metronidazole (photodegradation), i.e. as the radiation energy becomes stronger, the degradation rates increases. Furthermore, the rate of degradation was found to follow pseudo-first order reaction. It was also found that as the exposure time of these drugs to radiation increased the degradation was amplified. For all three brands were used in the investigation, the average rate of degradation when using long UV irradiation, and short UV radiation as stress factors were found to be,-0.0061 day-1 and -0.026 day-1 respectively. The obtained results show that UV/vis spectroscopy is satisfactory technique at the determination of metronidazole degradation kinetics in e intravenous products.