This invention provides for, inter alia, spot-on compositions for the treatment or prophylaxis of parasite infestations in mammals or birds which comprise: (1) at least one nodulisporic acid derivative； (2) an acceptable liquid carrier vehicle； and (3) optionally, a crystallization inhibitor. The invention also provides for a method of treating parasitic infestations or for the prophylaxis of parasite infestations in mammals or birds which comprises topically applying to said mammal or bird an effective amount of a composition according to the present invention. Further, this invention relates to an amidation process to prepare amide derivatives of nodulisporic acid and to intermediate formed in this process.
