The present invention concerns esters of R-enantiomers of a non-steroidal anti-inflammatory drug, which is substantially free from the S-enantiomer. The compounds of the invention may be used in treating a disease or illness in a mammal. To this end, a composition comprising a compound mentioned above, or a pharmaceutically acceptable salt thereof where salt formation occurs, is administered to the mammal in an amount sufficient to elicit a chemopreventative effect or a chemoprotective effect or a therapeutic effect or a prophylactic effect.