Piperidine derivatives

A compound having the formula:

• ##STR160## wherein [R.sup.111 and R.sup.IV are the same or different and each is a straight or branched alkyl group having from 1 to 12 carbon atoms or R.sup.III and R.sup.IV together with the carbon atom to which they are each attached from a cycloalkyl group having from 5 to 12 carbon atoms,] Y is a straight- or branched alkyl group having from 1 to 12 carbon atoms, an alkenyl group having from 3 to 12 carbon atoms or an aralkyl group having from 7 to 12 carbon atoms and when q is 1, R.sub.12 is hydrogen or when q is 1 or 2, R.sub.12 is a saturated or unsaturated hydrocarbyl group containing up to 20 carbon atoms optionally substituted[, Y] by halogen or alkoxy having from 1 to 4 carbon atoms and q is 1 or 2 and a salt thereof selected from a phosphate, carbonate, sulfate, chloride, acetate, stearate, maleate, citrate, [tertrate] tartrate, [oxolate] oxalate, benzoate and substituted carbamate.