A highly concentrated, low salt-containing, biologically active syrup form
of IGF-I or variant thereof and methods for its preparation are provided.
This novel syrup form of IGF-I has an IGF-I concentration of at least
about 250 mg/ml, a density of about 1.0 g/ml to about 1.2 g/ml, and a
viscosity of about 13,000 centipoise (cps) to about 19,000 cps, as
measured at ambient temperature (23.degree. C.). The IGF-I syrup is
prepared by precipitating or partitioning IGF-I from solution, preferably
by adjusting the solution pH or by use of a solubility enhancer to
concentrate IGF-I in solution followed by removal of the solubility
enhancer. The precipitated syrup is useful as a means of storing IGF-I in
a stable form and as a means of preparing compositions comprising
biologically active IGF-I. Pharmaceutical compositions and kits
comprising this concentrated IGF-I syrup are provided. The precipitated
IGF-I syrup, IGF-I reconstituted from the IGF-I syrup, pharmaceutical
compositions, and kits are useful in IGF-I therapy directed to
IGF-I-responsive conditions.