IN-USE PERIODIn these examples; the

IN-USE PERIODIn these examples; the pharmacy bulk pack may be used for months while the ophthalmic eye-drop normally has a standard in-use period of 28 days or fewer. The eye-drop period of use is in agreement withguidance document CPMP/QWP/l59/962 and will be justified by the chemical stability and the preservative efficacy demonstrated during ICH-compliant stability studies. This is noted in the introductory text to the Ph Eur antimicrobial preservative effectiveness test ,which declares that the tests provide proof of 'adequate protection from adverse effects tbat may arise from microbìal contamination or proliferation during storage and use of the preparation'. This interpretation seems to be one of the rare instances of agreement among pharmacopoeias on the subjecet of antimicrobial preservative efficacy testing.