STABILITY OF AMOXICILLIN AND POTASSIUM CLAVULANATE IN CO-AMOXICLAV ORAL SUSPENSION

A study was carried out using high performance liquid chromatography ( HPLC) to determine the chemical stability of amoxycillin and potassium clavulanate in 250/62 co-amoxyclav oral suspension (Augmentin), store d at room temperature (RT, 20-degrees-C) and 8-degrees-C over a period of 11 days. The suspension was judged to be acceptable if its compone nts maintained at least 90% of their label concentrations. During the test period, the amoxycillin component was found to be more stable tha n the clavulanate. Amoxycillin was stable for 7 days at both temperatu res. Potassium clavulanate maintained at least 90% of its initial conc entration for 7 days at 8-degrees-C but showed more than 40% degradati on in the same time period at RT. For potassium clavulate the shelf-li fe, or time taken for the original concentration to drop to 90% of its value (t90) at RT was found to be 2 days.