Effect of topical liposomes containing paromomycin sulfate in the course of Leishmania major infection in susceptible BALB/c mice

The impact of phospholipids with high transition temperature to enhance redox-sensitive liposomal doxorubicin efficacy in colon carcinoma model

In this study, we have developed a redox-sensitive (RS) liposomal doxorubicin formulation by incorporating 10,10'-diselanediylbis decanoic acid (DDA) organoselenium compound as the RS moiety. Hence, several RS liposomal formulations were prepared by using DOPE, HSPC, DDA, mPEG2000-DSPE, and cholesterol. In situ drug loading using a pH gradient and citrate complex yielded high drug to lipid ratio and encapsulation efficiency (100%) for RS liposomes. Liposomal formulations were characterized in terms of size, surface charge and morphology, drug loading, release properties, cell uptake and cytotoxicity, as well as therapeutic efficacy in BALB/c mice bearing C26 tumor cells. The formulations showed an average particle size of 200 nm with narrow size distributions (PDI < 0.3), and negative surface charges varying from -6 mV to -18.6 mV. Our study confirms that the presence of the DDA compound in liposomes is highly sensitive to hydrogen peroxide at 0.1% w/v, resulting in a significant burst release of up to 40%. The in vivo therapeutic efficacy study in BALB/c mice bearing C26 colon carcinoma confirmed the promising function of RS liposomes in the tumor microenvironment which led to a prolonged median survival time (MST). The addition of hydrogenated soy phosphatidylcholine (HSPC) with a high transition temperature (Tm: 52-53.5°C) extended the MST of our 3-component formulation of F14 (DOPE/HSPC/DDA) to 60 days in comparison to Caelyx (PEGylated liposomal Dox), which is not RS-sensitive (39 days). Overall, HSPC liposomes bearing RS-sensitive moiety enhanced therapeutic efficacy against colon cancer in vitro and in vivo. This achievement unequivocally underscores the criticality of high-TM phospholipids, particularly HSPC, in significantly enhancing liposome stability within the bloodstream. In addition, RS liposomes enable the on-demand release of drugs, leveraging the redox environment of tumor cells, thereby augmenting the efficacy of the formulation.

Development of nano-liposomal human growth hormone as a topical formulation for preventing uvb-induced skin damage

Due to its involvement in skin maintenance and repair, topical administration of recombinant human growth hormone (rhGH) is an interesting strategy for therapeutic purposes. We have formulated and characterized a topical rhGH-loaded liposomal formulation (rhGH-Lip) and evaluated its safety, biological activity, and preventive role against UVB-induced skin damage. The rhGH-Lip had an average size and zeta potential of 63 nm and -33 mV, respectively, with 70 % encapsulation efficiency. The formulation was stable at 4 °C for at least one year. The SDS-PAGE and circular dichroism results showed no structural alterations in rhGH upon encapsulation. In vitro, studies in HaCaT, HFFF-2, and Ba/F3-rhGHR cell lines confirmed the safety and biological activity of rhGH-Lip. Franz diffusion cell study showed increased rhGH skin permeation compared to free rhGH. Animal studies in nude mice showed that liposomal rhGH prevented UVB-induced epidermal hyperplasia, angiogenesis, wrinkle formation, and collagen loss, as well as improving skin moisture. The results of this study show that rhGH-Lip is a stable, safe, and effective skin delivery system and has potential as an anti-wrinkle formulation for topical application. This study also provides a new method for the topical delivery of proteins and merits further investigation.

Redox-sensitive doxorubicin liposome: a formulation approach for targeted tumor therapy

In this study redox-sensitive (RS) liposomes manufactured using 10,10′-diselanediylbis decanoic acid (DDA), an organoselenium RS compound, to enhance the therapeutic performance of doxorubicin (Dox). The DDA structure was confirmed by 1H NMR and LC–MS/MS. Various liposomal formulations (33 formulations) were prepared using DOPE, Egg PC, and DOPC with Tm ˂ 0 and DDA. Some formulations had mPEG₂₀₀₀-DSPE and cholesterol. After extrusion, the external phase was exchanged with sodium bicarbonate to create a pH gradient. Then, Dox was remotely loaded into liposomes. The optimum formulations indicated a burst release of 30% in the presence of 0.1% hydrogen peroxide at pH 6.5, thanks to the redox-sensitive role of DDA moieties; conversely, Caelyx (PEGylated liposomal Dox) showed negligible release at this condition. RS liposomes consisting of DOPE/Egg PC/DDA at 37.5 /60/2.5% molar ratio, efficiently inhibited C26 tumors among other formulations. The release of Dox from RS liposomes in the TME through the DDA link fracture triggered by ROS or glutathione is seemingly the prerequisite for the formulations to exert their therapeutic action. These findings suggest the potential application of such intelligent formulations in the treatment of various malignancies where the TME redox feature could be exploited to achieve an improved therapeutic response.

Nanomedicine-based strategies to improve treatment of cutaneous leishmaniasis

Nanomedicine strategies were first adapted and successfully translated to clinical application for diseases, such as cancer and diabetes. These strategies would no doubt benefit unmet diseases needs as in the case of leishmaniasis. The latter causes skin sores in the cutaneous form and affects internal organs in the visceral form. Treatment of cutaneous leishmaniasis (CL) aims at accelerating wound healing, reducing scarring and cosmetic morbidity, preventing parasite transmission and relapse. Unfortunately, available treatments show only suboptimal effectiveness and none of them were designed specifically for this disease condition. Tissue regeneration using nano-based devices coupled with drug delivery are currently being used in clinic to address diabetic wounds. Thus, in this review, we analyse the current treatment options and attempt to critically analyse the use of nanomedicine-based strategies to address CL wounds in view of achieving scarless wound healing, targeting secondary bacterial infection and lowering drug toxicity.

Topical Amphotericin B Semisolid Dosage Form for Cutaneous Leishmaniasis: Physicochemical Characterization, Ex Vivo Skin Permeation and Biological Activity

Amphotericin B (AmB) is a potent antifungal successfully used intravenously to treat visceral leishmaniasis but depending on the Leishmania infecting species, it is not always recommended against cutaneous leishmaniasis (CL). To address the need for alternative topical treatments of CL, the aim of this study was to elaborate and characterize an AmB gel. The physicochemical properties, stability, rheology and in vivo tolerance were assayed. Release and permeation studies were performed on nylon membranes and human skin, respectively. Toxicity was evaluated in macrophage and keratinocyte cell lines, and the activity against promastigotes and intracellular amastigotes of Leishmania infantum was studied. The AmB gel remained stable for a period of two months, with optimal properties for topical use and no apparent toxic effect on the cell lines. High amounts of AmB were found in damaged and non-damaged skin (1230.10 ± 331.52 and 2484.57 ± 439.12 µg/g/cm², respectively) and they were above the IC₅₀ of AmB for amastigotes. Although there were no differences in the in vitro anti-leishmanial activity between the AmB solution and gel, the formulation resulted in a higher amount of AmB being retained in the skin, and is therefore a candidate for further studies of in vivo efficacy.

Searching for drugs for Chagas disease, leishmaniasis and schistosomiasis: a review

Chagas disease, leishmaniasis and schistosomiasis are neglected diseases (NDs) and are a considerable global challenge. Despite the huge number of people infected, NDs do not create interest from pharmaceutical companies because the associated revenue is generally low. Most of the research on these diseases has been conducted in academic institutions. The chemotherapeutic armamentarium for NDs is scarce and inefficient and better drugs are needed. Researchers have found some promising potential drug candidates using medicinal chemistry and computational approaches. Most of these compounds are synthetic but some are from natural sources or are semi-synthetic. Drug repurposing or repositioning has also been greatly stimulated for NDs. This review considers some potential drug candidates and provides details of their design, discovery and activity.

Development and Characterization of a Semi-Solid Dosage Form of Meglumine Antimoniate for Topical Treatment of Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL) is treated with painful intralesional injections of meglumine antimoniate (MA). With the aim of developing an alternative topical treatment for CL, a gel-based formulation with 30% MA was prepared and its physicochemical properties, stability and rheological behavior were studied. The following were assessed: drug release on propylene hydrophilic membranes ex vivo human skin permeation, tolerance in healthy volunteers, cytotoxicity in three cell lines and anti-leishmanial activity against Leishmania infantum promastigotes and amastigotes. The MA gel formulation was found to have suitable pH, and good spreadability and stability. Low quantities of pentavalent antimony (Sb^V) were observed in release and permeation tests, whereas retention was high in both non-damaged and damaged skin (71,043.69 ± 10,641.57 and 10,728 ± 2254.61 µg/g/cm² of Sb^V, respectively). The formulation did not have a toxic effect on the cell lines, and presented lower Sb^V IC₅₀ values against amastigotes (15.76 ± 4.81 µg/mL) in comparison with the MA solution. The high amount of drug retained in the skin and the Sb^V IC₅₀ values obtained suggest that this semi-solid dosage form has potential as an alternative treatment of CL.

Development of a topical liposomal formulation of Amphotericin B for the treatment of cutaneous leishmaniasis

BACKGROUND

Currently, there is no topical treatment available for any form of cutaneous leishmaniasis (CL) in most of the endemic areas. The aim of the current study was to develop a topical nano-liposomal Amphotericin B (AmB) for the treatment of CL.

METHODOLOGY/PRINCIPAL FINDINGS

Liposomes containing 0.1, 0.2 and 0.4% AmB (Lip-AmB) were formulated and characterized for the size, entrapment efficiency, long term stability, and skin penetration properties using Franz diffusion cells. Liposomes diameters were around 100 nm with no change during more than 20 months' storage either at 4 °C or at room temperature. Franz diffusion cells studies showed that almost 4% of the applied formulations penetrated across the skin and the highest skin retention (73.92%) observed with Lip-AmB 0.4%. The median effective doses (ED₅₀), the doses of AmB required to kill 50% of L. major amastigotes were 0.151, 0.151, and 0.0856 (μg/mL) in Lip-AmB 0.1, 0.2, 0.4%, respectively. Lip-AmB 0.4% caused 80% reduction in fluorescence intensity of GFP+ L. tropica infected macrophages at 5 μg/mL of AmB concentration. Topical Lip-AmB was applied twice a day for 4 weeks to the skin of BALB/c mice to treat lesions caused by L. major. Results showed the superiority of Lip-AmB 0.4% compared to Lip-AmB 0.2 and 0.1%. The parasite was completely cleared from the skin site of infection and spleens at week 8 and 12 post-infection in mice treated with Lip-AmB 0.4%. The results suggest that topical Lip-AmB 0.4% may be a useful tool in the treatment of CL and merits further investigation.

Targeted-nanoliposomal combretastatin A4 (CA-4) as an efficient antivascular candidate in the metastatic cancer treatment

A number of antiangiogenic drugs have been approved by the Food and Drug Administration which are used in cancer therapy, and variety of other agents in several stages of clinical development or in preclinical assessment. Among these, combretastatin A4 (CA-4) is an under-researched inhibitor of angiogenesis that shows potential activity in the treatment of advanced tumors with migration capacity. However, its clinical application has been limited due to poor water solubility, low bioavailability, rapid metabolism, and systemic elimination. During the last decade, numerous investigations have been done to overcome these problems by using different CA-4 delivery systems or developing produgs of CA-4 or its structural analogs. Nevertheless, these strategies could not be efficient out of the undesired side effects on normal tissues. Nanoliposomal CA-4 not only benefits from the advantage of using liposomal drugs as opposed to free drugs but also can accumulate in the tumor site via specific targeting ligands, which leads to efficient targeting and enhancement of bioavailability. To the best of our knowledge, we consider an important attempt to understand different factors that might influence the CA-4 loading and release pattern of liposomes and the consequent results in tumor therapy. In this review, we shed light on various studied liposomal CA-4 formulations showing application thereof in cancer treatment.

Development, characterization and evaluation of topical methotrexate-entrapped deformable liposome on imiquimod-induced psoriasis in a mouse model

The aim of this study was to prepare and characterize topical methotrexate (MTX) with different percentages (0.05%, 0.1%, 0.25% and 0.5%) entrapped in deformable liposomes using phosphatidylcholine and oleic acid. The effectiveness and sub-acute toxicity of these topical formulations were investigated in imiquimod (IMQ)-induced psoriasis in a mouse model (IMQP). The particle sizes of formulations were around 100 nm with a mean zeta potential of -72.87 mV. The entrapment efficiency (EE%) of MTX in liposomal formulations were more than 85%. Franz cell permeability studies indicated that permeation of MTX through the healthy BALB/c mice skin is very low; however, in the inflammatory skin, which was induced by IMQ it was significant (50%). Liposomal MTX (LM 0.05 and 0.1%) caused significant reduction of thickness score dose-dependently in IMQP compared to the injected MTX. Moreover, investigation of the inflammatory factor and pathological examinations of skin proved the superiority of the LM treating group. Pathological examinations also showed there are no toxicity in organs of the mice that received the LM. Blood cell count test didn't show any abnormality. MTX-entrapped deformable liposomes could be a topical option in future for the treatment of human psoriasis with a less toxicity and merit further investigations.

Development of topical liposomes containing miltefosine for the treatment of Leishmania major infection in susceptible BALB/c mice

Herein, we investigated the efficacy of liposomes for the topical delivery of miltefosine (ML) to treat cutaneous leishmaniasis (CL). Liposomes containing varying concentrations of ML (0.5, 1, 2 and 4%) were prepared and characterized by their size and entrapment efficiency. The liposome diameters were between 100-150 nm. The penetration of ML from liposomal formulations through and in the skin was assessed using ex-vivo Franz diffusion cells fitted with mouse skin at 37 °C for 24 h. Data indicated that Lip-ML-4% showed the highest percent of retention across mouse skin (82%). in vitro promastigote and amastigote assays showed that ML and Lip-ML inhibit the growth of parasites either in the culture medium or intracellularly. Lip-ML formulations were topically applied twice a day for 4 weeks to the skin of BALB/c mice infected with L. major. Results showed a significantly (p < 0.001) smaller lesion size in Lip-ML-2 and 4% when compared to controls. At week 8 post-infection, the number of parasites was higher in Lip-ML-0.5% compared to Lip-ML-2 and 4%, however, the difference was not significant. At week 12, the splenic parasite burden was significantly (p < 0.001) lower in mice treated with different Lip-ML formulations when compared to controls. The lesion parasite burden was significantly (p < 0.001) lower in mice treated with either Lip-ML-2 and 4% compared to Lip-ML-0.5% at week 12 post-infection. The results suggested that topical Lip-ML-4% showed optimal ex-vivo penetration and in vivo anti-leishmanial activity against CL caused by L. major when compared to ML cream and other liposomes and thus, merits further investigation.

Exploiting knowledge on pharmacodynamics-pharmacokinetics for accelerated anti-leishmanial drug discovery/development

Introduction: Being on the top list of neglected tropical diseases, leishmaniasis has been marked for elimination by 2020. In the light of small armamentarium of drugs and their associated drawbacks, the understanding of pharmacodynamics and/or pharmacokinetics becomes a priority to achieve and sustain disease elimination. Areas covered: The authors have looked into pharmacological aspects of existing and emerging drugs for treatment of leishmaniasis. An in-depth understanding of pharmacodynamics and pharmacokinetics (PKPD) provides a rationale for drug designing and optimizing the treatment strategies. It forms a key to prevent drug resistance and avoid drug-associated adverse effects. The authors have compiled the researches on the PKPD of different anti-leishmanial formulations that have the potential for improved and/or effective disease intervention. Expert opinion: Understanding the pharmacological aspects of drugs forms the basis for the clinical application of novel drugs. Tailoring drug dosage and individualized treatment can avoid the adverse events and bridge gap between the in vitro models and their clinical application. An integrated approach, with pragmatic use of technological advances can improve phenotypic screening and physiochemical properties of novel drugs. Concomitantly, this can serve to improve clinical efficacies, reduce the incidence of relapse and accelerate the drug discovery/development process for leishmaniasis elimination.

Evaluation of propylene glycol nanoliposomes containing curcumin on burn wound model in rat: biocompatibility, wound healing, and anti-bacterial effects

Curcumin is an effective wound healing agent in burn therapy, but due to its low bioavailability, it is required to be formulated for topical therapy. Liposomal nanocarriers are developed as stable and efficient dermal delivery systems. In this study, we prepared curcumin-propylene glycol liposomes (Cur-PgL) to treat animals subjected to second degree burns. The characterization tests confirmed the production of monodisperse nanoliposomes of average size of about 145 nm with high entrapment efficiency percentage and a sustained release behavior. TEM analysis of nanocarriers showed no aggregation in long time storage up to 60 days. The biocompatibility of the Cur-PgL formulation was evaluated by ISO standards. We found that Cur-PgL 0.3% was the effective dose in injured rats without any side effects on intact skin. The cytotoxicity of the Cur-PgL 0.3% nanovesicles was also assessed on human dermal fibroblast (HDF) cells. The results showed no detectable cytotoxicity, but considerable cytotoxicity was observed in higher concentration of 1.5 and 3 mg/ml of free and PgL forms of curcumin. Eight days of application of Cur-PgL on burned rats resulted in a significant (P<0.001) recovery of wound repair parameters, and after 18 days, wound contraction occurred significantly (P < 0.001) compared to the other groups. The antibacterial activity of the Cur-PgL formulation was found to be similar to the silver sulfadiazine (SSD) cream 1% regarding the inhibition of the bacterial growth. In conclusion, the low dose of curcumin nanoliposomal formulation efficiently improved injuries and infections of burn wounds and it can be considered in burn therapy.

Biosynthesized colloidal silver and gold nanoparticles as emerging leishmanicidal agents: an insight

Many recent key innovations in nanotechnology have greatly fascinated scientists to explore new avenues in treatment and diagnosis of emerging diseases. Due to extensive utilization of metallic nanoparticles (NPs) in diverse biomedical applications, scientists are looking forward to green synthesis of NPs as safer, simple, fast, and low-cost method over chemical and physical methods. Due to enriched phytochemistry, no need for maintenance and ready availability, plants are preferred for green synthesis of silver (AgNPs) and gold NPs (AuNPs). Recently, several researchers have exploited these biogenic NPs as potential antileishmanial agents. The current article is focused to mechanistically explain the antileishmanial activity of biogenic AuNPs and AgNPs with a futuristic discussion on the faith of these particles as emerging antileishmanial agents.

Biodistribution and In Vivo Antileishmanial Activity of 1,2-Distigmasterylhemisuccinoyl-sn-Glycero-3-Phosphocholine Liposome-Intercalated Amphotericin B

1,2-Distigmasterylhemisuccinoyl-sn-glycero-3-phosphocholine (DSHemsPC) is a new lipid in which two molecules of stigmasterol (an inexpensive plant sterol) are covalently linked via a succinic acid to glycerophosphocholine. Our previous study revealed that liposome (Lip)-intercalated amphotericin B (AMB) prepared from DSHemsPC (DSHemsPC-AMB-Lip) possesses excellent colloidal properties and in vitro antifungal and antileishmanial activities similar to those of the liposomal AMB preparation AmBisome. The aim of this study was to determine the biodistribution and evaluate the antileishmanial effects of DSHemsPC-AMB-Lip in Leishmania major-infected BALB/c mice. The serum profile and tissue concentrations of AMB were similar in DSHemsPC-AMB-Lip- and AmBisome-treated mice after intravenous (i.v.) injection. Multiple i.v. doses of the micellar formulation of AMB (Fungizone; 1 mg/kg of body weight), DSHemsPC-AMB-Lip (5 mg/kg), and AmBisome (5 mg/kg) were used in L. major-infected BALB/c mouse models of early and established lesions. In a model of the early lesions of cutaneous leishmaniasis (CL), the results indicated that the level of footpad inflammation was significantly (P < 0.001) lower in mice treated with DSHemsPC-AMB-Lip and AmBisome than mice treated with empty liposomes or 5% dextrose. The splenic and footpad parasite load was also significantly (P < 0.001) lower in these groups of mice than in control mice that received 5% DW or free liposome. The in vivo activity of DSHemsPC-AMB-Lip was comparable to that of AmBisome, and both provided improved results compared to those achieved with Fungizone at the designated doses. The results suggest that systemic DSHemsPC-AMB-Lip administration may be useful for the treatment of leishmaniasis, and because it costs less to produce DSHemsPC-AMB-Lip than AmBisome, DSHemsPC-AMB-Lip merits further investigation.

Therapeutic Efficacy of Cisplatin Thermosensitive Liposomes upon Mild Hyperthermia in C26 Tumor Bearing BALB/c Mice

This study reports on the activity of thermosensitive liposomes (TSLs) incorporating different HSPC ratios in DPPC/MSPC/PEG₂₀₀₀-DSPE matrix (90/10/4) plus mild hyperthermia (HT) (42 °C). TSLs were loaded with a poorly membrane permeable anticancer drug, cisplatin, through the passive equilibration method. The addition of HSPC to the corresponding DPPC lipid matrix increased the transition temperature. In vitro data demonstrated >90% cisplatin leakage from nanosized DPPC 90-lyso-TSL (LTSL) within 10 min at 42 °C, while other TSLs bearing HSPC showed greater stability. The plasma kinetics of cisplatin demonstrated higher cisplatin leakage from DPPC 90-LTSL in the first 4 h (from 17.4 to 0.4 μg/mL) compared to other formulations. Indeed, increasing HSPC fraction in liposome bilayers significantly improved drug retention in blood. Though DPPC 90-LTSL plus one-step HT was expected to provide a unique drug release, the premature drug leakage as well as the likely wash-back of a great portion of drug into the blood circulation resulted in reduced survival. On the other hand, stabilized DPPC 30/HSPC 60/MSPC 10/PEG₂₀₀₀-DSPE 4 liposomes plus two-step HT greatly enhanced the survival of animals. In particular, the improved delivery of cisplatin through stabilized DPPC 30/HSPC 60/MSPC 10/PEG₂₀₀₀-DSPE 4 liposomes in two-step mild HT enhanced antitumor efficacy compared to other formulations. Thus, prolonged exposure of cancer cells to cisplatin through stabilized liposomes would be an efficient approach in improving the survival of animals.

Drug Targeting to Macrophages With Solid Lipid Nanoparticles Harboring Paromomycin: an In Vitro Evaluation Against L. major and L. tropica

Leishmaniasis is a worldwide disease that leads to high mortality and morbidity in human populations. Today, leishmaniasis is managed via drug therapy. The drugs that are already in clinical use are limited to a number of toxic chemical compounds and their parasite drug resistance is increasing. It is therefore essential, in order to circumvent the current difficulties, to design a new anti-leishmanial drug treatment strategy. Besides producing new, active anti-leishmanial entities, another promising strategy could be developing novel delivery systems and formulations of the existing pharmaceutical ingredients to improve drug efficacy. In the present study, paromomycin sulfate (PM), as one of the promising anti-leishmanial drugs, was formulated in solid lipid nanoparticles (SLN), and its in vitro efficacy was investigated against different strains of Leishmania using a MTT test, Parasite-Rescue-Transformation-Assay, SYTO Green staining, and fluorescent microscope imaging. The results show that PM-loaded SLN is significantly more effective than PM in inhibiting parasite propagation (P < 0.05) and that cytotoxicity of PM-SLN formulations is size dependent. According to our results, delivery of the drugs to the macrophages via nanoparticle utilization seems to be an accessible and practical approach.

Preparation and physicochemical characterization of topical chitosan-based film containing griseofulvin-loaded liposomes

Griseofulvin is an antifungal drug and is available as oral dosage forms. Development of topical treatment could be advantageous for superficial fungal infections of the skin. In this study, films prepared from the incorporation of griseofulvin-loaded liposomes in chitosan film for topical drug delivery in superficial fungal infections. The properties of the films were characterized regarding mechanical properties, swelling, ability to transmit vapor, drug release, thermal behavior, and antifungal efficacy against Microsporum gypseum and Epidermophyton floccosum. The presence of liposomes led to decreased mechanical properties but lower swelling ratio. Higher amount of drug permeation and rate of flux were obtained by liposomes incorporated in films compared to liposomal formulations. Antifungal efficacy of formulations was confirmed against two species of dermatophytes in vitro. Therefore, two concepts of using vesicular carrier systems and biopolymeric films have been combined and this topical novel composite film has the potential for griseofulvin delivery to superficial fungal infections.

Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery

Background

The aim of this study was to develop and optimize deformable liposome for topical delivery of tretinoin.

Methods

Liposomal formulations were designed based on the full factorial design and prepared by fusion method. The influence of different ratio of soy phosphatidylcholine and transcutol (independent variables) on incorporation efficiency and drug release in 15 min and 24 h (responses) from liposomal formulations was evaluated. Liposomes were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The penetration and retention of drug was determined using mouse skin. Also skin histology study was performed.

Results

Particle size of all formulations was smaller than 20 nm. Incorporation efficiency of liposomes was 79–93 %. Formulation F7 (25:5) showed maximum drug release. Optimum formulations were selected based on the contour plots resulted by statistical equations of drug release in 15 min and 24 h. Solubility properties of transcutol led to higher skin penetration for optimum formulations compared to tretinoin cream. There was no significant difference between the amount of drug retained in the skin by applying optimum formulations and cream. Histopatological investigation suggested optimum formulations could decrease the adverse effect of tretinoin in liposome compared to conventional cream.

Conclusion

According to the results of the study, it is concluded that deformable liposome containing transcutol may be successfully used for dermal delivery of tretinoin.

Developing cutaneous applications of paromomycin entrapped in stimuli-sensitive block copolymer nanogel dispersions

AIM

A new paromomycin micellar nanogel based on poloxamer 407 was developed.

MATERIALS & METHODS

 In vitro release and ex vivo permeation/retention studies were conducted. In vivo tolerance was assayed by transepidermal water loss. Ex vivo cytotoxicity on RAW and VERO cells and antileishmanial activity on Leishmania promastigotes was tested.

RESULTS

The particle size was 9.19 nm (99% loading efficiency) exhibiting Newtonian behavior at 4°C and was pseudoplastic at 25 and 40°C. Drug release followed a Weibull model and the drug remaining in the skin was 31.652 µg/g/cm(2). In vivo tolerance achieved excellent results with negligible cellular toxicity and the best antileishmanial efficiency.

CONCLUSION

The nanogel provided controlled, effective and safe delivery of paromomycin for the treatment of cutaneous leishmaniasis.

Effect of topical Nanoliposomes of Paromomycin on Rats Liver and Kidney

Background:

Hepatotoxicity due to drugs is the most common cause of deaths. Nephrotoxicity of the drugs is usually associated with the drugs accumulation in renal tissue. Paromomycin sulfate (PMS) is an anti-leishmania drug. Although the topical approach for the treatment of leishmania is attractive, its use might cause nephrotoxicity and hepatotoxicity.

Objectives:

This study aimed to evaluate probable nephrotoxicity and hepatotoxicity of topically administered PMS liposomes.

Materials and Methods:

Nine groups of male rats were used in this study; each group consisted of 6 rats that were evaluated in 3 time periods of 10, 20, and 30 days. Three groups were placed in each time period; a control group did not receive any medicine; a negative control group received liposome without paromomycin sulfate; and a positive control group received nanoliposomal formulations containing paromomycin sulfate. Pharmaceutical formulation (topical form) was used 2 times a day in a 12-hour interval. At the end of the period, hepatic enzymes (ALT, AST, and ALK), BUN levels, and serum creatinine were measured.

Results:

The results showed that no significant change was occurred in the amount of the above factors compared with the control group with the negative control group in 3 time periods (P > 0.05). The histopathological results of the liver and kidney showed that there was no difference in the between the negative control and positive control groups and the control group in the 10- and 20-day periods, and they had a normal structure. However, after the 30-day time period a reversible cellular inflammation in the liver and mild kidney necrosis was seen in the positive control group versus the control and negative control groups.

Conclusions:

In general, it can be said that the application of nanoliposomal paromomycin sulfate formulations for topical treatment of the cutaneous leishmaniasis does not create serious side effects in the short term, but its long-term use leads to mild renal and liver side effects that requires more attention.

Enhanced photodynamic leishmanicidal activity of hydrophobic zinc phthalocyanine within archaeolipids containing liposomes

In this work, the in vitro anti-Leishmania activity of photodynamic liposomes made of soybean phosphatidylcholine, sodium cholate, total polar archaeolipids (TPAs) extracted from the hyperhalophile archaea Halorubrum tebenquichense and the photosensitizer zinc phthalocyanine (ZnPcAL) was compared to that of ultradeformable photodynamic liposomes lacking TPAs (ZnPcUDLs). We found that while ZnPcUDLs and ZnPcALs (130 nm mean diameter and -35 mV zeta potential) were innocuous against promastigotes, a low concentration (0.01 μM ZnPc and 7.6 μM phospholipids) of ZnPcALs irradiated at a very low-energy density (0.2 J/cm(2)) eliminated L. braziliensis amastigotes from J774 macrophages, without reducing the viability of the host cells. In such conditions, ZnPcALs were harmless for J774 macrophages, HaCaT keratinocytes, and bone marrow-derived dendritic cells. Therefore, topical photodynamic treatment would not likely affect skin-associated lymphoid tissue. ZnPcALs were extensively captured by macrophages, but ZnPcUDLs were not, leading to 2.5-fold increased intracellular delivery of ZnPc than with ZnPcUDLs. Despite mediating low levels of reactive oxygen species, the higher delivery of ZnPc and the multiple (caveolin- and clathrin-dependent plus phagocytic) intracellular pathway followed by ZnPc would have been the reason for the higher antiamastigote activity of ZnPcALs. The leishmanicidal activity of photodynamic liposomal ZnPc was improved by TPA-containing liposomes.

Drug delivery: lessons to be learnt from Leishmania studies

Background Leishmaniasis is a disease caused by infection with the protozoan parasite Leishmania, which is responsible for three main types of disease: cutaneous leishmaniasis, visceral leishmaniasis and mucocutaneous leishmaniasis based to the site of infection for the particular species. This presents a major challenge to successful drug treatment, as a drug must not only reach antileishmanial concentrations in infected macrophages, the parasites' host cell, but also reach infected cells in locations specific to the type of disease. In this paper we discuss how studies using Leishmania have contributed to our knowledge on how drug delivery systems can be used to improve drug efficacy and delivery.

Nanoparticles as multifunctional devices for the topical treatment of cutaneous leishmaniasis

INTRODUCTION

Cutaneous and mucocutaneous leishmaniasis are major tropical skin diseases. Topical treatment is currently limited to the least severe forms of cutaneous leishmaniasis (CL) without risk of dissemination. It is also recommended in combination with systemic therapy for more severe forms. Progresses in this modality of treatment are hindered by the heterogeneity of the disease and shortcomings in the clinical trials.

AREAS COVERED

This review overlooks three major modalities of topical therapies in use or under investigation against CL: chemotherapy, photodynamic therapy and immunotherapy; either with older compounds such as paramomycin or more recent nitric oxide donors, antimicrobial peptides or silver derivatives. The advantages and limitations of their administration with newer formulation strategies such as nanoparticles (NPs) are discussed.

EXPERT OPINION

The efficacy of a topical treatment against CL depends not only on the intrinsic antileishmanial activity of the drug but also on the amount of drug available in the dermis. NPs as sustained release systems and permeation enhancers could favour the creation of a drug reservoir in the dermis. Additionally, certain NPs have immunomodulatory properties or wound healing capabilities of benefit in CL treatment. Pending task is the selective delivery of active compounds to intracellular amastigotes, because even small NPs are unable to penetrate deeply into the skin to encounter infected macrophages (except in ulcerative lesions).

The efficacy of hydro alcoholic extract of Seidlitzia rosmarinus on experimental zoonotic cutaneous leishmaniasis lesions in murine model

OBJECTIVE

Leishmaniasis is one of the most important parasitic infectious diseases in the world. Since last century, many efforts have been made to control and treat the disease, but appropriate vaccines, pesticides and medicines are not available or even eligible. The purpose of this study was to evaluate the effect of hydro-alcoholic extract of Seidlitzia rosmarinus on the lesions of experimental Cutaneous Leishmaniasis (CL) in Balb/c mice.

MATERIALS AND METHODS

The population study was 60 Ballb/c mice which divided to 6 groups, all infected with Leishmania major [MRHO/75/IR]. Soon after the ulcer started to appear in the early stage, a dose of provided herbal extract with 5, 10 and 15% concentration applied on each lesion. The surface area of the lesions measured during an interval of 10 days. Direct Giemsa stained smears prepared two and four weeks after treatment.

RESULTS

Increasing the mean size of the lesions was statistically significant compared to those in control group (p>0.001). Visceral Leishmaniasis (VL) developed in all of the mice including the control group that received Eucerine alone. Survival rate in group receiving 15% S. rosmarinus extracts showed significantly higher compared to mice in control group (p<0.001).

CONCLUSION

Hydro-alcoholic extracts of S.rosmarinus with concentrations below15% did not show a therapeutic effect on experimental CL ulcers of Balb/c mice. Further studies with higher concentrations or nano particles are recommended.

Colloidal, in vitro and in vivo anti-leishmanial properties of transfersomes containing paromomycin sulfate in susceptible BALB/c mice

The aim of this study was to develop transfersomal formulation with respect to dermal delivery of paromomycin sulfate (PM) for possible topical therapy of cutaneous leishmaniasis (CL). PM transfersomal formulations (PMTFs) with different percent of soy phosphatidylcholine, sodium cholate (Na-Ch) and ethanol were prepared and characterized for the size, zeta potential and encapsulation efficiency. The results showed that the most stable formulations with suitable colloidal properties were obtained by 2% Na-Ch which had average size of around 200 nm. The in vitro permeation study using Franz diffusion cells fitted with mouse skin at 37°C for 24h showed that almost 23% of the PMTFs applied penetrated the mouse skin, and the amount retained in the skin was about 67% for both formulations; however, the percent of penetration and retention for PM conventional cream was 49 and 13, respectively. The 50% effective doses of PMTFs against Leishmania major promastigotes and amastigotes in culture were significantly less than cream and/or solution of PM. Selected PMTFs and empty transfersomes showed no cytotoxicity in J774 A.1 mouse macrophage cell line. Selected PMTFs was used topically twice a day for 4 weeks to treat L. major lesions on BALB/c mice, and the results showed a significantly (P<0.05) smaller lesion size in the mice in the treated groups than in the mice in the control groups, which received either empty transfersomes or phosphate-buffered saline (PBS) and also PM cream. The spleen parasite burden was significantly (P<0.01) lower in mice treated with selected PMTFs than in mice treated with PBS or control transfersomes, and PM cream. The results of this study showed that PMTFs prepared with 2% of Na-Ch with and without 5% ethanol might be useful as a candidate for the topical treatment of CL.

Treatment of cutaneous lesion of 20 years' duration caused by leishmanization

The inoculation of live Leishmania (L.) major to produce a single lesion is called leishmanization (LZ). LZ lesion upon cure prevents further natural infection which might be multiple lesions on unwanted sites such as face. Cutaneous leishmaniasis (CL) usually leads to a self healing lesion; though rarely the lesion persists and becomes refractory to all types of remedies. Here, we present a 41-year-old patient with a 20-year history of cutaneous lesion caused by leishmanization. The causative agent is identified as L. major. The patient did not respond to treatment with meglumine antimoniate, 20 mg/kg/day Sb(+5) for three weeks and allopurinol 10 mg/kg for four weeks. After two months, the same treatment was repeated. In addition, a topical liposomal preparation containing 10% paromomycin sulfate was administered twice a day for four weeks. The lesion showed marked improvement during the treatment and was eventually completely healed.

Drug delivery systems for the topical treatment of cutaneous leishmaniasis

INTRODUCTION

The parenteral administration of pentavalent antimonials for the treatment of all forms of leishmaniasis, including cutaneous leishamniasis (CL), has several limitations. Therapy is long, requiring repeated doses and the adverse reactions are frequent. Topical treatment is an attractive alternative for CL, offering significant advantages over systemic therapy: fewer adverse effects, ease of administration, and lower costs.

AREAS COVERED

This review covers, from 1984 to the present, the progress achieved for the development of topical treatment for CL, using different drugs such as paromomycin (PA), imiquimod, amphotericin B (AmB), miltefosine, and buparvaquone. PA is the most commonly studied drug, followed by AmB and Imiquimod. These drugs were incorporated in conventional dosage forms or loaded in lipid nanocarries, which have been used mainly for improved skin delivery and antileishmanial activity.

EXPERT OPINION

Developing an effective topical treatment for CL using these antileishmanial drugs still remains a great challenge. Insights into the most promising delivery strategies to improve treatment of CL with PA and AmB using conventional dosage forms, lipid nanocarriers, and combined therapy are presented and discussed. The results obtained with combined therapy and alternative delivery systems are promising perspectives for improving topical treatment of CL.

Antileishmanial Activity of Liposomal Clarithromycin against Leishmania Major Promastigotes

OBJECTIVES

Cutaneous leishmaniasis is a common parasitic disease which is endemic in some parts of the world. In vitro and in vivo studies have shown azithromycin efficacy on some Leishmania species. Because of structural similarity between clarithromycin and azithromycin and efficacy of clarithromycin against intracellular organisms and due to the absence of previous studies in this respect, we decided to evaluate the efficacy of clarithromycin against promastigotes of L. major in vitro.

MATERIALS AND METHOD

First, liposomal and non- liposomal clarithromycin were prepared, then both forms of the drug were incubated with promastigotes for 24 hr in NNN culture media without red phenol in the presence of 5% FCS with different concentrations as follows: 20, 40, 80, 100, 200 and 500 µg/ml.

RESULTS

According to the results, clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major. The concentration of drug that killed 50% of parasites (ED 50) was 169 and 253.6 µg/ml for liposomal and non- liposomal forms, respectively which shows that lower concentrations of liposomal drug are required to have the same effect as non- liposomal drug and the liposomal form of the drug is more effective than non- liposomal form.

CONCLUSION

Clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major.

Leishmanicidal Activity of Films Containing Paromomycin and Gentamicin Sulfate both In Vitro and In Vivo

BACKGROUND

Based on the efficacy of paromomycin ointment and recent ongoing clinical trials of combination of paromomycin and gentamicin, a new physical form of films of the paromomycin and gentamicin was prepared and anti-Leishmania activities of the prepared films were assessed in vitro and in vivo.

METHODS

Paromomycin 15% and gentamicin 0.5% was incorporated in a film using ethyl cellulose and HPMC (Hydroxyl Propyl Methyl Cellulose). In order to assess the drug release and anti-Leishmania activities of the preparation, a clone L. major parasite was established using a set of modified NNN medium without overlay liquid layer. Therapeutic effects of the films were evaluated using Balb/c mice model. The mice were inoculated with 2×10(6)L. major promastigotes (MRHO/IR/75/ER) and then when the lesions developed the mice were randomly divided in 3 groups, 10 mice per group, and treated with either perpetrated films or placebo for 28 days or left untreated.

RESULTS

Growth inhibition of cloned promastigotes showed that the films have enough releasing capacity and in vivo system, the films containing paromomycin and gentamicin was able to reduce the lesion size and induced complete cure in 80% of the mice but relapse was seen in 60% of the cured mice and overall 50% cure rate was seen during 20 weeks period of the study.

CONCLUSION

It seems that the prepared films might be further used in human clinical trials.

Characterization of the colloidal properties, in vitro antifungal activity, antileishmanial activity and toxicity in mice of a di-stigma-steryl-hemi-succinoyl-glycero-phosphocholine liposome-intercalated amphotericin B

1,2-Di-stigma-steryl-hemi-succinoyl-sn-glycero-3-phosphocholine (DSHemsPC) is a new lipid in which two molecules of stigmasterol (an inexpensive plant sterol) are covalently linked via a succinic acid to glycerophosphocholine. Since amphotericin B (AmB) interacts with sterols, we postulated that DSHemsPC could be used in AmB liposome formulations. Thirty-two DSHemsPC-AmB formulations were prepared using various mole ratios of DSHemsPC, phosphatidylcholine and phosphatidylglycerol at different pH. Most formulations had physical properties similar to AmBisome™: a particle diameter of about 100 nm, a monomodal distribution and a negative zeta potential. The red blood cell potassium release (RBCPR) IC50s for formulations spanned a range, with some being comparable to or greater than the IC50 observed using AmBisome™. A number of formulations had superior in vitro antifungal activity compared to AmBisome™ against all of the tested pathogenic yeasts and molds. The IC50s of formulations against Leishmania major promastigotes and amastigotes for certain formulations were comparable with AmBisome™ and Fungizone™. Most formulations had maximum tolerated intravenous doses (MTD) of less than 10 mg/kg. However the formulation consisting of DSHemsPC/DMPC/DMPG/AmB mole ratio 1.25/5.0/1.5/1.0 (prepared at pH 5.5) had excellent colloidal properties, a high IC50 for RBCPR, antifungal and antileishmanial activity similar to AmBisome™ and an MTD of 60 mg/kg. The characteristics of this DSHemsPC/DMPC/DMPG/AmB formulation make it suitable for further investigation to treat AmB-responsive pathogens.

Combination therapy with paromomycin-associated stearylamine-bearing liposomes cures experimental visceral leishmaniasis through Th1-biased immunomodulation

Visceral leishmaniasis (VL) caused by the parasite Leishmania donovani is a potentially fatal disease. Available limited drugs are toxic, require prolonged treatment duration, and are costly. A low-cost parenteral formulation of paromomycin sulfate (PM) has recently been approved for the treatment of VL. Monotherapy with PM runs the risk of development of resistance. Hence, efforts are needed to develop a combination therapy of PM with other drugs to shorten the duration of treatment and prolong the effective life of the drug. PM was formulated with leishmanicidal stearylamine (SA)-bearing phosphatidylcholine (PC) liposomes for low-dose therapy. In vitro and in vivo antileishmanial effects of the combination drug were determined. The immunomodulatory role of PC-SA-PM was determined using enzyme-linked immunosorbent assay (ELISA) and flow cytometry. Excluding the spleen, for which the therapeutic effect was additive, a remarkable synergistic activity toward cure and prophylaxis with a single-shot low-dose treatment with PC-SA-associated PM was achieved with BALB/c mice. PC-SA-PM showed an immunomodulatory effect on CD4(+) and CD8(+) T cells for gamma interferon (IFN-γ) production and downregulated disease-associated interleukin-10 (IL-10) and transforming growth factor β (TGF-β) to almost negligible levels. Such combination chemotherapy may provide a promising alternative for the cure of leishmaniasis, with a plausible conversion of the host immune response from a disease-promoting pattern to a Th1-biased response indicative of long-term resistance.

Preparation, characterization and evaluation of sun protective and moisturizing effects of nanoliposomes containing safranal

OBJECTIVES

The objective of this study was to prepare, characterize and evaluate the nanoliposomes containing safranal as a natural sunscreen and moisturizer factor.

MATERIALS AND METHODS

The experimental formulations included homosalate reference, nanoliposomes containing 0.25, 0.5, 1, 2, 4 and 8% safranal and empty liposomes. The liposomes were prepared using fusion method and homogenization. Homosalate reference was prepared according to FDA standard. Sun protection factors (SPF) of the formulations were determined by two in vitro methods; diluted solution transmittance method and transpore tape method. Studies of in vitro penetration of the formulations across mouse skin were carried out with diffusion cells. The percentage of safranal penetrated and retained in the skin was determined for the formulations up to 24 hr. The amount of the moisture contents of the skin before application and after 30-minute, 1, 3 and 5 hr post-application of the formulations were measured in human volunteers using Corneometer.

RESULTS

The results indicated that, the SPF of liposomes containing 8% safranal (Lip-Safranal 8%) was significantly higher than 8% homosalate reference. The proportion of Lip-Safranal 1% that penetrated the skin was low. There was no significant difference between the skin moisture contents after application of Lip-Safranal 1 and 4% and empty liposomes during the 7 hr post-application period.

CONCLUSION

These results showed that in equal concentrations, Lip-Safranal could act as a better antisolar agent compared to homosalate and have no moisturizing effect in 1 and 4% concentrations.