The present invention relates to improvements in the oral formulations of the anthelmintic praziquantel used for control and treatment of endoparasitic infestations in warm-blooded animals in particular in companion animals such as cats, dogs and horses and methods of producing the formulations. The composition of the invention comprises particles of praziquantel with an integral coating of a lipid or a mixture of lipids which are insoluble in water and which serve to mask to extremely bitter taste of praziquantel upon oral administration but which disperse or dissolve on contact with gastrointestinal tract and thus do not influence the bioavailability of the drug substance. The present invention also provides compositions for oral administration of praziquantel in cats and dogs which are substantially free of the bitter taste associated with praziquantel and comprise a dispersion of the lipid-coated particles of praziquantel in suitable vehicle. According to a yet further aspect, the invention provides a method of masking the bitter taste of praziquantel which comprises coating praziquantel with a suitable lipid or a mixture of lipids and incorporating the lipid-coated particles into oral formulations, for example into tablets, oral pastes or gels.
