A composition showing an improved bioavailability rate of pantothenic acid derivatives represented by the following general formula and improved storage stability and being applicable as drugs over an enlarged range: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each represents a hydrogen atom or a hydroxyl-protective group; R.sup.3 represents a saturated or unsaturated, linear, branched or cyclic C.sub.5-25 monovalent aliphatic hydrocarbon group optionally substituted by an aromatic group, or an amino group represented by the formula --N(R.sup.4)R.sup.5 (wherein R.sup.4 represents a saturated or unsaturated, linear, branched or cyclic C.sub.5-25 monovalent aliphatic hydrocarbon group; and R.sup.5 represents a hydrogen atom or a saturated or unsaturated, linear, branched or cyclic monovalent aliphatic hydrocarbon group optionally substituted by an aromatic group); A represents a saturated or unsaturated, linear, branched or cyclic C.sub.2-16 divalent aliphatic hydrocarbon group, divalent aromatic hydrocarbon group or divalent heteroaryl group optionally substituted by an aromatic group; one of X and Y represents an amino group represented by the formula --N(R.sup.6)-- while the other represents --O--, --S-- or an amino group represented by the formula --N(R.sup.7)-- (wherein R.sup.6 and R.sup.7 represent each a hydrogen atom or a lower alkyl group); and n is an integer of from 1 to 4. The pantothenic acid derivative represented by the above general formula (I) is dissolved in a neutral or alcoholic ester and a nonionic surfactant is added thereto to give the absorption-enhancing composition.