Pharmacokinetics of benznidazole in experimental Trypanosoma cruzi-infected mice after oral administration of benznidazole-clomipramine dual-loaded multiparticulate drug delivery systems

DEL ROSSO, SEBASTIAN; GUZMÁN, LAURA; BERGERO, GASTÓN; MAZZOCCO, YANINA; JIMÉNEZ-KAIRUZ, ALVARO; OLIVERA, MARÍA EUGENIA; GARCÍA, MÓNICA; AOKI, MARIA DEL PILAR

Santa Fé

Congreso; 7th International Reunion of Pharmaceutical Sciences; 2023

Chagas disease (CD) represents an important multidimensional health problem in Latin America and worldwide due to its high prevalence, morbidity, and mortality. Benznidazole (BZ) is the selected drug for its treatment; however, high frequency of administration, long-term treatment, and several side effects negatively affect therapeutic success. Therefore, novel alternative strategies to improve the current etiological treatments have been proposed, among them drug delivery systems (DDS) and new anti-T. cruzi molecular targets. Clomipramine (CMP) is a parasite-trypanothione reductase-specific inhibitor and acts synergically with BZ, which allows for the use of low doses of BZ, reducing inflammation and cardiac tissue damage during the chronic phase of experimental CD. We have developed BZ-loaded multiparticulate DDS (MDDS) that showed controlled drug release. This strategy diminishes side effects of BZ and allow reducing its frequency of administration, while combined therapy with CMP synergizes anti-T. cruzi activity of BZ. The aim of this study was to assess the preclinical plasmatic pharmacokinetics (PK) of BZ in T. cruzi-infected mice after an oral administration of MDDS-BZ-CMP combined therapy compared to BZ-CMP as free drugs. BALB/c mice (n=36) were i.p. infected with 103 trypomastigotes Tulahuen strain. After 15 days, mice were randomly divided into 2 groups: MDDS-BZ50 received doses of BZ 50 and CMP 7.5 mg·kg-1 combined therapy formulated as MDDS and BZ50 received the same doses of both drugs in their free form. Treatments were administered by oral gavage. At 0.5; 1, 2, 3, 4 and 5 h post-administration blood samples were obtained by cardiac puncture. BZ quantification was performed in plasma by high performance liquid chromatography validated method. PKSolver software add-in for Excel, which relies on the use of non-compartmental methods of analysis, was used for estimation of PK parameters. The maximum plasma BZ concentration (Cmax), the time to reach this concentration (tmax), and elimination half-life (t1/2) were determined from BZ plasma concentration vs. time curves. The areas under the curve from zero to the last sampling point (AUC0-t) and from zero to infinity (AUC0-∞) were estimated by the trapezoidal rule by the software. The results indicated appropriate bioavailability of BZ after administration of both treatments (AUC ~1500-1600 μg·mL-1·min-1). Even though no significant differences were observed in PK parameters, Cmax of BZ50 group was slightly higher than that of MDDS-BZ50 group (8 μg·mL-1 and 6 μg·mL-1, respectively; difMDDS-BZ ± SEM = (-1,27 ± 0.76) μg·mL-1) and BZ50 group reached it at 2 h post-administration while MDDS-BZ50 exhibited a tmax at 3 h. t1/2 values were lower for BZ50 compared to MDDS-BZ50 group (1 h and 2 h, respectively; difMDDS-BZ ± SEM = (1.0 ± 0.8) h). Thus, PK parameters showed that the BZ-MDDS prolonged drug release and seemed to increase the maintenance of drug concentration in vivo, which would allow reducing the frequency of administration.