Anthelmintic Transdermal route Bioavailability Dog Praziquantel (PZQ), a synthetic isoquinoline-pyrazine derivative, is an anthelmintic used for the treatment of infections caused by various species of trematodes and cestodes in domestic animals.
There are available both oral and subcutaneous dosage forms for administration of PZQ to dogs, but not transdermal formulations, which do exist for administration to cats.
The transdermal route of administration achieved via spot-on formulations has several advantages over the oral or subcutaneous forms; among them are the possibility of a controlled administration, the minimization of hazardous animal handling by the operator and a better tolerability for the animal, as it reduces the risk of vomiting and of pill rejection. Furthermore, the simplicity of the administration procedure shall very likely contribute to treatment adherence, thus increasing treatment effectivity. Regarding this matter, a critical analysis of the effectiveness of cystic echinococcosis eradication programs in South America demonstrated that the use of PZQ for 30.
￼￼Praziquantel (PZQ) is an anthelmintic drug used both in humans and animals that can be administered through various routes. There are transdermal formulations for cats, but only oral or subcutaneous dosage forms for dogs. Given the fact that the cat’s skin and the dog’s skin have different characteristics, which in turn affect bioavailability, we developed a PZQ spot-on formulation for dogs. This study was aimed at determining the plasmatic behavior of topically administered PZQ (Labyes®) in adult dogs.
Dogs were administered PZQ (14.5 mg/kg PZQ, from a solution of 100 mg/ml). Blood samples were drawn before treatment onset and at the following time points after PZQ administration: 1, 2, 4, 6, 12, 24 and 48 h. PZQ plasma concentration was determined by ultra-high performance liquid chromatography (UPLC) coupled to tandem mass spectrometry (MS/MS). Observed maximum concentration (Cmax), area under the concentration–- time curve from the time of drug administration to infinity (AUCinf) and time to maximum concentration (Tmax) were calculated for each animal, and mean ± SD for each parameter was obtained.