a system for delivering a growth hormone releasing peptide including a peptide , or a pharmaceutically acceptable salt form thereof , alternatively conjugated to a polymer via a biodegradable bond and dissolved in a liquid medium . because extra - cellular fluids in vivo provide the appropriate environment to efficiently degrade peptides , the growth hormone releasing peptide will maintain chemical integrity and remain substantially coupled to the polymer while circulating through the body . the therapeutic agent is , therefore , protected from degradation and clearance .