The invention relates to polymorphic forms of the calcium salt of N-(3-carboxyl-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-(2R)-methyl butanoic acid ethyl ester. The calcium salt of N-(3-carboxyl-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-(2R)-methyl butanoic acid ethyl ester is useful in the treatment of various conditions and disorders responsive to the inhibition of neutral endopeptidases.
