PT - JOURNAL ARTICLE AU - Robert L. Abshire AU - Barry A. Schlech TI - A Method for Evaluating the Effectiveness of Preservative Systems in Water-Immiscible Ointments DP - 1982 Sep 01 TA - PDA Journal of Pharmaceutical Science and Technology PG - 216--221 VI - 36 IP - 5 4099 - http://journal.pda.org/content/36/5/216.short 4100 - http://journal.pda.org/content/36/5/216.full SO - PDA J Pharm Sci Technol1982 Sep 01; 36 AB - A procedure designed specifically for determining the effectiveness of antimicrobial preservatives in an ophthalmic ointment was evaluated. Except for Staphylococcus aureus, the United States Pharmacopeia XX battery of challenge microorganisms worked well in the system. The results indicate that this procedure can be used to challenge preserved ointments and determine if such preparations meet the same test requirements as those set forth in the compendium for preserved solutions and suspensions. It is proposed that other laboratories study this method so that its usefulness for evaluating the effectiveness of preservatives in ointments can be defined.