definiens: means any modification, addition, improvement, adaptation or variation in the Process from the written procedures as agreed to by the parties that ( i ) impaas the regubtory commitments for Product, ( ii ) may require revalidation, ( Ui ) may affect the quality, purity, identity, stability or strength of Product, Of ( iv ) would necessarily result in cha.nging, altering or modifying Product Specifications, test methods, sampling procedures or drug master file relanng to Product " PEG ' means polycthyleneglycol, including but not limited to the following compounds : PEG2MAL40 K ( maleimidoproprionamide of bis ( merhoxypoly ( erhyleneglycol ), MW 20,000 Oa ) modified lysine ) and PEG2bisMAL40 K ( bis - maleimido terminated bis ( methoxypoly ( ethyleneglycoll, MW 20,000 Oa ) modified lysine )