Media bulk was manufactured at the beginning of the challenge. pharm.

[Natuli]

Помогите, плз!!
Как бы Вы перевели указанное в теме предложение, что здесь обозначает "challenge"?
Validation Summary for Bulk Hold Time.
Validation studies also established a 13 day sterile bulk holding time. Media challenge of Unitdose bulk hold time occurred between December 3, 2002 and December 18, 2002.
In order to achieve these objectives, the study was conducted as described below.
Media bulk was manufactured at the beginning of the challenge (day 1). The bulk hold time period was started at the beginning of media filtration At the end of the filling period (day 13), a minimum of 5000 pipettes of media were filled. At the end of the bulk hold time, a media sample was taken from the holding tank.

[Fatima CHiza]

Challenge, в данном случае использован во избежании повтора слова Study.
Перевожу: Фильтрующий материал подготавливается в самом начале опыта (исследования).

[GhostLibrarian]

Fatima почему фильтрующий материал?
на proz Вам уже ответили :)

[Natuli]

Fatima CHiza, GhostLibrarian, спасибо.

[Fatima CHiza]

because media bulk = filter bed = filtruyushaya zagruzka = filtruyushiy material = kontaktnaya zagruzka filtra(whatever)