Pharmaceutical products for curing and preventing illnesses connected with the malfunction of vascular endothelial cells

A pharmaceutical product for the treatment and prevention of illnesses resulting from damaged vascular endothelial cells, said product comprising, as an active ingredient, 0.5-95.5 m/m % of a hydroxylamine derivative represented by general formula (I) ##STR5## or the salts of optically active forms thereof, wherein R.sup.1 and R.sup.2 independently comprise a hydrogen atom or a straight or branched alkyl group of 1 to 6 carbon atoms, or R.sup.1 and R.sup.2 together with the nitrogen atom in-between form a saturated 5-7 membered heterocyclic group, optionally containing additional nitrogen and/or oxygen heteroatoms,

• A comprises a straight or branched alkyl group of 4 to 12 carbon atoms, a phenyI group, substituted or unsubstituted, containing an alkyl-, haloalkyl- or nitro group as substituent, or a 5-6 membered heteroaromatic ring containing nitrogen, oxygen or sulphur,
• in general formula (I) Z comprises a covalent bond, and in general formula (II) Z comprises a covalent bond or a .dbd.NH group,
• in general formula (I) X comprises a halogen atom or a --NR.sup.3 R.sup.4 group, wherein R.sup.3 and R.sup.4 independently comprise a hydrogen atom or a straight or branched alkyl group of 1 to 6 carbon atoms, while in general formula (II) X comprises an oxygen atom,
• in general formula (II) R' comprises a hydrogen atom or a straight or branched alkyl group of 1 to 6 carbon atoms, and
• in general formulae (I) and (II) Y comprises a hydrogen atom, a hydroxyl group or an acyloxy group, which contains the acyl part of a long chain fatty acid of 8 to 22 carbon atoms, or of a cyclic aromatic carboxylic acid as its acyl component,
• and in the compounds of general formula (I) when X comprises a --NR.sup.3 R.sup.4 group and Y comprises a hydroxyl group, the X group is condensed with the Y substituent to form the intramolecular ring represented by general formula (III), ##STR6## in which formula A, Z, R.sup.1 and R.sup.2 comprise the elements defined above or the salts and optically active forms thereof.