Stability Study of the Co-amoxiclav Original Brand Oral Suspension (312.5/5ml) after Reconstitution at Recommended Conditions and at-Home Storage Conditions

Co-amoxiclav for pediatric use comes as oral powder, which has to be reconstituted before administration. Concerns have been raised regarding the appropriateness of environmental conditions. A stability study was carried out on the original brand (Augmentin) suspension which were reconstituted and kept under the standard storage conditions of 2-8ºC and at home conditions (25ºC). Both compounds (amoxicillin and clavulanic acid) were considered stable if they retained 90% of their initial concentrations. From the study, it was found that the home conditions had no significant detrimental effect on the stability of amoxicillin but had a significant on stability of clavulanic acid, throughout the duration of therapy (10 days). However. The standard storage temperature should be adhered to stringently to guarantee maximum therapeutic benefit. This revealed that amoxicillin remained stable throughout the duration of therapy but clavulanic acid did not. Physical compatibility was assessed by visual observation for discoloration and precipitation throughout the duration of therapy. The chemical stability of the drug was analyzed by HPLC instrumental method. The various parameters analyzed include description, odor, color, taste, assay, water content, specific gravity, and pH. These parameters were evaluated at zero day, 3rd day, 7th day, 10th day intervals. The results of assay indicate that the samples are within the allow able limits (90-120%) for amoxicillin at recommended conditions and home conditions, but the storage of Augmentin suspension at home conditions (25ºC). showed that the  clavulanic acid rapidly exposed to degradation directly after reconstitution of all batches after 3 days, the assay test were out the limit, however, when stored at refrigerator temperature (2-8ºC) the degradation of clavulanic acid is very low after prolong period (about 10 days). The results of amoxicillin concentration in all tested batches that were stored at 2-8ºC were very similar to the results of assay that were stored at room temperature. Key words: stability evaluation, amoxicillin, clavulanic acid, degradation, reconstitution.