Bracketed Stability Evaluation of Methimazole USP in PLO Gel Mediflo™30 Pre-Mixed

Extemporaneously compounded Methimazole 1% and 10% in PLO Gel Mediflo™30 Pre-Mixed were studied to assess physical, chemical and microbial stability over time. The formulations were stored at room temperature in tightly closed, light resistant plastic containers. Chemical stability was evaluated using a validated, stability indicating HPLC analysis and physical stability was evaluated through observation of organoleptic appearance and pH measurement at predetermined time points. Lastly, antimicrobial effectiveness testing was conducted per USP <51> guidelines. The results indicate that compounded Methimazole remained within the stability criteria for the duration of the study and can be assigned an extended beyond-use-date of 120 days under the studied conditions.