The impact of isopropanol and carbomer type on physicochemical characteristics of bioadhesive thermoresponsive platforms for eprinomectin delivery

Abstract

Environmentally responsive systems composed of poloxamer 407 (P407) and different carbomers were investigated for eprinomectin delivery, as they can show improved properties for skin administration and permeation. Eprinomectin shows great efficacy against endo and ectoparasites, but its hydrophobicity is a challenge for the development of formulations. This work aimed to evaluate the influence of P407 amount, carbomer type and isopropyl alcohol (IA) concentration on sol-gel transition, compressional, rheological, drug release, bioadhesive and skin permeation properties of designed systems for topical administration of eprinomectin. Systems composed of different amounts of P407 and Carbomer 974P or 934P were proposed. The influence of IA amount and the eprinomectin presence was also investigated. Drug and IA reduced the structuring capacity and the compressional properties of systems. Preparations displayed bioadhesive force influenced by the carbomer type and drug presence. The higher P407 amount, the presence of C974P and the temperature increase enhanced the bioadhesiveness and structuring of systems. The selected formulations displayed drug release controlled by anomalous transport, and the formulations improved the bovine skin permeation of eprinomectin. P407 (17.5 %), 15 % IA, 0.3 % C974P and 0.5 % eprinomectin showed rendered an efficient system for controlled topical delivery and suggest it is worthy of in vivo evaluation.