Abstract The aim of this work was to develop an oral solution of captopril at 5 mg/mL preservative-free. Two formulations were prepared, one containing sweetener (formulation 1) and the other without this excipient (formulation 2). The results found of validation parameters from analytical method performed by HPLC for captopril were, linearity 0.9998, the limit of detection 15.71 µg/mL, the limit of quantification 47.60 µg/mL, repeatability 1.05%, intermediate precision 2.42%, accuracy intraday 101,53%, accuracy inter-day 99.85%. Moreover, the results found for captopril disulfide were, linearity 0.9999, limit of detection 0.65 µg/mL, limit of quantification 1.96 µg/mL, repeatability 2.28%, intermediate precision 1.51%, accuracy intraday 101.36%, accuracy inter-day 100.29%. The appearance of formulations was clear and colorless, pH measures were 3.12 and 3.04, dosage of captopril and captopril disulfide were 99.45% and 99.82%, 0.24% and 0.12% for formulation 1 and formulation 2, respectively. The stability study demonstrated that the concentration of captopril and captopril disulfide in the formulations was > 90% and below 3%, respectively. The in vivo palatability study in animals and humans showed that Formulation 1 containing the sweetener had better acceptance. Thus, the sweetener was able to improve the unpleasant taste of the formulation.

ABSTRACT Background: Accidents caused by spiders of the genus Loxosceles constitute an important public health problem in Brazil. The venom of Loxosceles sp induces dermonecrosis at the bite site and systemic disease in severe cases. Traditional medicine based on plant-derived products has been proven to reduce the local effects of envenomation. The present study verified the healing effects of copaiba oil on lesions induced by the venom of L. intermedia. Methods: Cutaneous lesions were induced on the backs of rabbits by intradermal injection of L. intermedia venom. Copaiba oil was applied topically 6 hours after injection; the treatment was repeated for 30 days, after which animal skins were removed and processed for histopathological analysis. Blood samples were also collected before and 24 hours after venom inoculation to measure the hematological parameters. Results: Compared to the control group, the platelet count was reduced significantly in all groups inoculated with venom, accompanied by a decreased number of heterophils in the blood. The minimum necrotic dose (MND) was defined as 2.4 μg/kg. Topical treatment with copaiba oil demonstrated a differentiated healing profile: large skin lesions were observed 10 days after venom inoculation, whereas formation of a thick crust, without scarring was observed 30 days after venom inoculation. Histopathological analysis showed no significant difference after treatment. Nevertheless, the copaiba oil treatment induced a collagen distribution similar to control skin, in marked contrast to the group that received only the spider venom injection. Conclusions: We conclude that copaiba oil may interfere in the healing process and thus propose it as a possible topical treatment for cutaneous lesions induced by L. intermedia venom.