Preliminary comparative study of a topical formulation of hexadecylphosphocholine (HPC) with the gold standard intramuscular meglumine antimoniate in a murine model of cutaneous leishmaniasis

GÓMEZ-GALINDO AM.; GLISONI R.J.; GRANADOS-FALLA D.; SOSNIK A.; DELGADO G.

Basel, Switzerland

Congreso; CLINAM The European Summit for Clinical Nanomedicine and Targeted Medicine; 2014

The European Summit for Clinical Nanomedicine and Targeted Medicine

Introduction: Gold standard treatments against leishmaniasis are parenteral and associated with adverse effects that compromise the adherence to the therapeutic regimens and favor the development of antimicrobial resistance. For these reasons, efforts directed to reduce the use of traditional drugs or to obtain a better-tolerated and effective treatment are a first priority of the World Health Organization. In this work, we evaluated for the first time the antileishmanial efficacy of free hexadecylphosphocholine (HPC) and its inclusion complex with hydroxypropyl-beta-cyclodextrin (HPbeta-CD), dispersed in a water-in-oil (W/O) cream, on a murine model of the cutaneous infection and compared it to a conventional intramuscular formulation containing meglumine antimoniate (AIM). Materials and Methods: 10 BALB/c female mice (one mouse for Group 1 and three mice Groups 2, 3 and 4) four weeks of age from the central biotery of the Faculty of Veterinary Medicine and Zootechny (Universidad Nacional de Colombia) were housed in the animal facility of the Department of Pharmacy (Faculty of Sciences, Universidad Nacional de Colombia). Mice had a quarantine period of two weeks before being infected. Animals were kept in individual transparent polycarbonate boxes (One Cage 2100TM AllerZoneTM Micro-IsolatorTM) with bedding and ad libitum access to fresh water and LabDiet®. The assays were performed in accordance to the provisions provided in the Colombian law 84 of 1989 (National Statute for the Protection of Animals) and under Title V of Resolution 008430 of 1993 emitted by the Ministry of Health about biomedical research involving animals. Mice were infected with 1 x 107 promastigotes of Leishmania panamensis (MHOM/CO/87/UA140), provided by Dr. Sara Robledo (Universidad de Antioquia, Colombia) by intradermal inoculation at the lumbosacral area using a 1 mL syringe. After the primo-infection, animals were maintained for six weeks to allow the formation of cutaneous ulcers with a mean size of 6 mm. This was the final point to start the treatment employing the different samples (Table 1). One hundred mg of each formulation (W/O cream Groups 2-4, Table 1) was properly applied to each lesion once-a-day until its disappearance. Then, lesions were covered with bandages. The clinical follow up was done twice-a-week (registering data about food/water consumption, general status and weight). In addition, the size of the lesion was measured with a Vernier Calliper, which allowed determining the area of each lesion (transverse diameter of the lesion X sagittal diameter of the lesion) at each time point. Once a week, the size of the lesion was recorded and at day 32, the animals were sacrificed according to the Guidelines on Euthanasia of the American Veterinary Medical Association. Samples of lesion skin, inguinal lymphonodes, liver and spleen were collected in order to conduct histopathology and immunohistochemistry analysis (including CD4+ and CD8+ cell populations). With lesion diameters, we established the index of evolution of the lesion (IE) as the ratio between the initial area of the lesion and area of the lesion at a given time point. Results: In animals treated with HPC W/O cream, the IE was similar or slightly greater than INT (animals treated with drug-free W/O cream) during the first 3 weeks (Figure 1). Then, a gradual decline of the efficacy was observed. Complexation with the cyclodextrin increased the efficacy over the whole the treatment, IE being similar or greater even than that of the standard AIM.