MACO = (0.35 mg/day × 200,000 FTUs × 25.0 cm2 /swab) / (162.0 FTUs/day × 6000 cm2 ) =1.80 mg/swab
Other criteria typically used in the industry include 10 ppm criterion and visually clean criterion. The former is based on
the assumption that not more than 10 ppm of any pharmaceutical ingredient should appear in any other product, and the latter
is not an assumption but rather a fixed value of 0.1 mg/25 cm2 swab area obtained after performing spiking studies. The lowest value obtained from all the MACO calculations based on different
criteria is then selected as the acceptance limit for active A1.
The determination of MACO for a pharmaceutical agent to the subsequently manufactured product is an inexact science. Each
approach has its own set of assumptions and limitations. Any firm that relies on MACO values for their cleaning validation
studies must understand the assumptions used in deriving the MACO values. It is the responsibility of pharmaceutical manufacturers
and cleaning validation scientists tasked with setting MACO values to estimate a value that is safe for consumers without
being so demanding that resources are spent unnecessarily.
M. Ovais* is a pharmaceutical scientist, Xepa-Soul Pattinson (M) Sdn Bhd, 1-5, Cheng Industrial Estate, 75250 Melaka, Malaysia, tel.
006063351515, fax 006063355829, firstname.lastname@example.org
Lai Yeo Lian is the innovation and development manager at Xepa-Soul Pattinson (M), Laiyl@xepasp.com
*To whom all correspondence should be addressed.
Submitted: June 5, 2007. Accepted:July 26, 2007
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