Tolouei et al.: Leishmanicidal Activity of Films Containing Paromomycin… Fig. 1: Ulcer size in Balb/c mice infected with L. major, animals were treated with drug films or placebo or left untreated for 28 days (4 weeks) Discussion Although leishmaniasis is a major health problem in some of the endemic areas(12) , no vaccine is available against any form of leishmaniasis (10-13). Available chemother- apy against CL is limited and daily injec- tions is difficult to tolerate by the patients and justifies search for more practical formulation of chemotherapy and topical therapy is highly acceptable if available (14- 16).Therapeutic activities of paromomycin against CL is tested in several clinical trials, although the results are not consistent but the overall showed that at least paromomycin is effective against some Leishmania strains (5,7,15,17,18). Combination of paromomy- cin and gentamicin was showed to cure L. major and L. mexicana in infected Balb/c mice (19). The same formulation called WR279396 was checked in phase 2 trials and showed to be safe with acceptable cure rate and cur- rently is in phase 3 clinical trial in Tunesia 63 and Columbian male army (9, 20) (Personal communication with Alan Magill and Max Grogl). In the current study, a new form of film containing of paromomycin and gen- tamicin was prepared and tested in vitro against L. major growth and in vivo against L. major infection in Balb/c mice. Paromomycin is effective against Leishma- nia infection and gentamicin is a wide spec- trum antibiotic that has synergic effects in combination of paromomycin (17-19). In this study, drug films were shown to be effective against in vitro promastigote growth with inhibition rate of 98% within 5 days. The in vivo results indicated that the new physical form of combination of paromomycin and gentamicin was able to significantly (P<0.05) reduce the lesion size in Balb/c mice. Drug films were able to in- duce lesion cure in 80% of the mice at 28 days after the treatment initiation. However relapses characterized by the reappearance