TY - JOUR T1 - A Method for Evaluating the Effectiveness of Preservative Systems in Water-Immiscible Ointments JF - PDA Journal of Pharmaceutical Science and Technology JO - PDA J Pharm Sci Technol SP - 216 LP - 221 VL - 36 IS - 5 AU - Robert L. Abshire AU - Barry A. Schlech Y1 - 1982/09/01 UR - http://journal.pda.org/content/36/5/216.abstract N2 - 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. ER -