Novel crystalline Form I of trisodium [3-((1S,3R)-1-biphenyl-4-ylmethyl-3-ethoxycarbonyl-1-butylcarbamoyl) propionate-(S)-3'-methyl-2'- (pentanoyl {2"-(tetrazol-5-ylate)biphenyl-4'-ylmethyl}amino)butyrate] hydrate, methods for its preparation, pharmaceutical compositions comprising the new form, and use of them for treating or delaying progression or onset of diseases or disorders related to activity of angiotensin receptor 1 (AT1) blockage and neprilysin (NEP) inhibition, such as heart failure, are disclosed.