Prodrug for therapeutic applications

A prodrug of fingolimod comprising an acid-labile linkage that when exposed to an environment that has a pH<7.0 releases the parent drug fingolimod, wherein the prodrug comprises the structure of Formula II:

• or a pharmaceutically acceptable salt or solvate thereof,
• wherein,
• R6 is selected from H, D,
• optionally substituted (C1-C30)alkyl, optionally substituted (C1-C30)heteroalkyl, optionally substituted (C1-C30)alkenyl, optionally substituted (C1-C30)heteroalkenyl, optionally substituted (C1-C30)alkynyl, optionally substituted (C1-C30)heteroalkynyl, optionally substituted aryl, optionally substituted (C3-C12)cycloalkyl, optionally substituted (C4-C12)cycloalkenyl, optionally substituted heterocycle, optionally substituted heteroaryl, optionally substituted mixed ring system, optionally substituted (C2-C30)-alkoxy, optionally substituted (C2-C30)-ester, polyethyleneimine, poly(glycolic acid), a poly(lactic acid), poly(glycolic-co-lactic acid), chitosan, poly(methacrylic acid), poly(acrylic acid), polycaprolactone, poly(ethylene/vinyl acetate), poly(vinyl acetate), poly(vinyl methyl ether), poly(vinyl alcohol), poly (N-isopropylacrylamide), —OH, a lipid, a saccharide, a polysaccharide, a nucleic acid, an amino acid, a peptide, a peptoid, a fatty acid, ethylene glycol, and polyethylene glycol;
• and
• R7 is selected from an optionally substituted (C1-C30)alkyl, optionally substituted (C1-C30)heteroalkyl, optionally substituted (C1-C30)alkenyl, optionally substituted (C1-C30)heteroalkenyl, optionally substituted (C1-C30)alkynyl, optionally substituted (C1-C30)heteroalkynyl, optionally substituted aryl, optionally substituted (C3-C12)cycloalkyl, optionally substituted (C4-C12)cycloalkenyl, optionally substituted heterocycle, optionally substituted heteroaryl, optionally substituted mixed ring system, optionally substituted (C2-C30)-alkoxy, optionally substituted (C2-C30)-ester, polyethyleneimine, poly(glycolic acid), a poly(lactic acid), poly(glycolic-co-lactic acid), chitosan, poly(methacrylic acid), poly(acrylic acid), polycaprolactone, poly(ethylene/vinyl acetate), poly(vinyl acetate), poly(vinyl methyl ether), poly(vinyl alcohol), poly (N-isopropylacrylamide), —OH, a lipid, a saccharide, a polysaccharide, a nucleic acid, an amino acid, a peptide, a peptoid, a fatty acid, ethylene glycol, and polyethylene glycol.