Pyriproxyfen-based Rumino-Reticulum Device for horn fly control in cattle: development and characterization

Abstract

This study aimed to develop a pyriproxyfen-based Rumino-Reticulum Device (RRD) consisting of films of poly(vinyl)alcohol (PVA) and sodium carboxymethylcellulose (NaCMC) to control the horn fly in cattle, one of the major pests of livestock. Films were obtained by the solvent casting method by PVA/NaCMC crosslinking and presented satisfactory homogeneity, drug content (104.8%) and pH (6.5), besides great absorptive capacity with swelling degree of 331.40% after 1 hour and diffusion-controlled release kinetics (Higuchi). FTIR and SEM analyzes clarify the characteristic bands of PVA, NaCMC and pyriproxyfen. The XRD and thermal analysis shows an increase in crystallinity due to pyriproxyfen (Xc:36.59%) and the active delivery alters the chain packing (Tg:74ºC). The pyriproxyfen-based RRD developed, in addition to fulfilling the characteristics of prolonged release, allows it to be rolled up (compressed form) facilitating swallowing and subsequent conversion to an expanded form that is retained in the rumen throughout the treatment period.

Keywords:
intra-ruminal release; horn fly; polymeric films