Evaluating the potential of polyester nanoparticles for per oral delivery of amphotericin B in treating visceral leishmaniasis.

Leishmaniasis is a protozoan disease, which is responsible for response for major epidemics in many parts of the World. Amphotericin B (AMB) is one of the drugs used to treat leishmaniasis but it must be given intravenously and serious side effects such as nephrotoxicity can limit its use. Development of a formulation of AMB, which can be given by a non-invasive route but is still as effective as the conventional formulation, whilst causing minimal adverse side effects, is required. The present study describes a method for scale up production of a per oral nanoparticle formulation of AMB (AMB-NP) and compared its efficacy both in vitro and in vivo against Leishmania donovavni. Prophylactic studies showed that the AMB-NP formulation was significantly more effective (p < 0.05) than the same dose of AMB solution at suppressing parasite numbers compared to controls in bone marrow derived macrophages infected with L. donovani. Per oral treatment with AMB-NP resulted in a significant reduction in liver parasite burdens (p < 0.05) compared to control values and the formulation had a similar antileishmanial activity against parasites with different inherent susceptibilities to sodium stibogluconate.

The efficacy of aerosol treatment with non-ionic surfactant vesicles containing amphotericin B in rodent models of leishmaniasis and pulmonary aspergillosis infection.

Amphotericin B (AMB) is used to treat both fungal and leishmanial infections, which are of major significance to human health. Clinical use of free AMB is limited by its nephrotoxicity, whereas liposomal AMB is costly and requires parenteral administration, thus development of novel formulations with enhanced efficacy, minimal toxicity and that can be applied via non-invasive routes is required. In this study we analysed the potential of non-ionic surfactant vesicles (NIV) given by nebulisation to deliver AMB to the lungs, liver and skin. Treatment with AMB-NIV resulted in significantly higher drug levels in the lungs and skin (p<0.05) compared to similar treatment with AMB solution but significantly lower plasma levels (p<0.05). Treatment with AMB-NIV resulted in a significant reduction in fungal lung burdens in a rat model of invasive pulmonary aspergillosis (p<0.05) compared to treatment with the carrier alone. Treatment with AMB-NIV but not AMB solution significantly suppressed Leishmania donovani liver parasite burdens (p<0.05) but could not inhibit the growth of cutaneous Leishmania major lesions. The results of this study indicate that aerosolised NIV enhanced pulmonary and hepatic delivery whilst minimising systemic exposure and toxicity.

Biodegradable nanoparticles improve oral bioavailability of amphotericin B and show reduced nephrotoxicity compared to intravenous Fungizone.

PURPOSE: Amphotericin B (AMB), an effective antifungal and antileishmanial agent associated with low oral bioavailability (0.3%) and severe nephrotoxicity, was entrapped into poly(lactide-co-glycolide) (PLGA) nanoparticles to improve the oral bioavailability and to minimize the adverse effects associated with it. MATERIALS AND METHODS: The AMB-nanoparticles (AMB-NP) were prepared by nanoprecipitation method employing Vitamin E-TPGS as a stabilizer. In vitro release was carried out using membrane dialysis method. The in vitro hemolytic activity of AMB-NP was evaluated by incubation with red blood cells (RBCs). The acute nephrotoxicity profile and oral bioavailability of AMB-NP were evaluated in rats. RESULTS: The prepared AMB-NP formulation contained monodispersed particles in the size range of 165.6 +/- 2.9 nm with 34.5 +/- 2.1% entrapment at 10% w/w initial drug loading. AMB-NP formulation showed biphasic drug release, an initial rapid release followed by a sustained release. The AMB-NP formulation exerted lower hemolysis and nephrotoxicity as compared to Fungizone. The relative oral bioavailability of the AMB-NP was found to be approximately 800% as compared to Fungizone. CONCLUSION: Together, these results offer a possibility of treating systemic fungal infection and leishmaniasis with oral AMB-NP, which could revolutionize the infectious disease treatment modalities.

High-performance liquid chromatographic analysis of amphotericin B in rat plasma using alpha-naphthol as an internal standard.

A simple, sensitive and accurate reverse phase high-performance liquid chromatographic (RP-HPLC) method with photo-diode array detector (PDA) was developed and validated for the determination of amphotericin B (AMB) in the rat plasma using a new internal standard (IS) alpha-naphthol. The plasma samples were subjected to protein precipitation with methanol prior to a HPLC analysis. Chromatographic separations were achieved on a Nucleosil 100-5C18 (150 mm x 4.6 mm) column. The mobile phase consisted of acetonitrile and sodium acetate buffer (pH 4; 10mM) in a gradient mode. Detection was carried out at a wavelength of 407 and 294 nm for AMB and IS, respectively. The retention times of AMB and IS were about 6.8 and 7.8 min, respectively. The calibration curve was linear in the range of 10-2000 ngmL(-1) for AMB (r(2)>0.998). No significant matrix effect was observed on quantification of AMB or IS. At three quality control concentrations of 20, 500, and 2000 ngmL(-1), the intra-day and inter-day relative standard deviation ranged from 1.13% to 4.91%. The limit of detection (LOD) was 5 ngmL(-1) and the limit of quantification (LOQ) was 10 ngmL(-1) for AMB in rat plasma. This method is simple, sensitive, rapid and does not require any extensive sample purification before injecting into HPLC.

PLGA nanoparticles for oral delivery of cyclosporine: nephrotoxicity and pharmacokinetic studies in comparison to Sandimmune Neoral.

The cyclosporine-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) were prepared by the emulsion-diffusion-evaporation method and were optimized for particle size and entrapment efficiency. The optimized particles were 143.3+/-8.7 nm in size with narrow size distribution and 71.9+/-1.7% entrapment efficiency at 20% w/w initial drug loading when prepared with 0.1% w/v of Didodecylmethylammonium bromide (DMAB) as stabilizer. These particulate carriers exhibited controlled in vitro release of cyclosporine for 23 days at a nearly constant rate and showed very good hemocompatibility in vitro. The nanoparticulate formulation showed significantly higher intestinal uptake as compared to Sandimmune Neoral and cyclosporine suspension. The relative bioavailability of nanoparticulate formulation was found to be 119.2% as compared to Sandimmune Neoral. A marked difference in the pharmacokinetic profile between nanoparticulate and Sandimmune Neoral formulations was observed where nanoparticulate formulation showed controlled release of cyclosporine over 5 days, on the other hand, the marketed formulation showed a sharp Cmax with a 3-day release profile. The nanoparticulate formulation exerted significantly lower nephrotoxicity in the rats as compared to Sandimmune Neoral, which was evidenced by lower blood urea nitrogen (BUN), plasma creatinine (PC) and malondialdehyde (MDA) levels in plasma and kidney. The results were further supported by the histopathological changes in kidneys. Together, these results indicate that PLGA NPs have greater potential for oral delivery of cyclosporine.

Development of biodegradable nanoparticles for oral delivery of ellagic acid and evaluation of their antioxidant efficacy against cyclosporine A-induced nephrotoxicity in rats.

PURPOSE: Ellagic acid (EA), a dietary antioxidant associated with poor biopharmaceutical properties, was encapsulated into poly(lactide-co-glycolide) (PLGA) and polycaprolactone (PCL) nanoparticles to improve oral bioavailability. MATERIALS AND METHODS: EA-loaded nanoparticles were prepared following emulsion-diffusion-evaporation method employing didodecyldimethyl ammonium bromide (DMAB) and polyvinyl alcohol (PVA) as stabilizers. In vitro release was investigated in phosphate buffer (pH 7.4). The in situ permeation studies were performed in rats. The antioxidant potential of the DMAB-stabilized nanoparticulate formulations was evaluated against cyclosporine A (CyA)-induced nephrotoxicity in rats. RESULTS: EA-loaded PLGA and PCL nanoparticles have been successfully prepared employing PEG 400 as co-solvent to solubilize EA. The stabilizers influenced the particle size and encapsulation efficiency. DMAB when used as stabilizer to particles of approximately 120 nm and approximately 50% encapsulation, whereas PVA led to approximately 290 nm and approximately 60% encapsulation at 5% initial loading (w/w of polymer). The in vitro release of EA from the nanoparticles followed Higuchi's square root pattern and was faster with PVA-stabilized particles in comparison to those stabilized with DMAB. From the in situ permeation studies in rats, it was evident that intestinal uptake of EA as DMAB-stabilized nanoparticles was significantly higher as compared to the sodium carboxymethyl cellulose suspension and the PVA-stabilized particles. EA and EA nanoparticles were able to prevent the CyA-induced nephrotoxicity in rats as evident by biochemical parameters as well as kidney histopathology. CONCLUSION: The present study demonstrates the potential of EA nanoparticulate formulations in the prevention of CyA-induced nephrotoxicity at three times lower dose suggesting improved oral bioavailability of EA.

Biodegradable in situ gelling system for subcutaneous administration of ellagic acid and ellagic acid loaded nanoparticles: evaluation of their antioxidant potential against cyclosporine induced nephrotoxicity in rats.

Ellagic acid (EA) is a potent antioxidant marketed as a nutritional supplement. Its pharmacological activity has been reported in wide variety of disease models; however its use has been limited owing to its poor biopharmaceutical properties, thereby poor bioavailability. The objective of the current study was to develop chitosan-glycerol phosphate (C-GP) in situ gelling system for sustained delivery of ellagic acid (EA) via subcutaneous route. EA was incorporated in the system employing propylene glycol (PG) and triethanolamine (TEA) as co-solvents; on the other hand EA loaded PLGA nanoparticles (np) were dispersed in the gelling system using water. These in situ gelling systems were thoroughly characterized for mechanical, rheological and swelling properties. These systems are liquid at room temperature and gels at 37 degrees C. The EA C-GP system showed an initial burst release in vitro with about 85% drug released in 12 h followed by a steady release till 160 h, on the other hand EA nanoparticles entrapped in the C-GP system displayed sustained release till 360 h. The histopathological analysis indicates the absence of inflammation on administration, suggesting that these formulations are safe during the studied period. Furthermore, the antioxidant potential of EA C-GP and EA np C-GP gels has been evaluated against cyclosporine induced nephrotoxicity in rats. The data indicates that formulations were effective against cyclosporine induced nephrotoxicity, where the EA C-GP gels showed activity at 10 times lower dose and the EA np C-GP gels at 150 times lower dose when compared to orally given EA. Formulating nanoparticles of EA and incorporating them in C-GP system results in 15 times lowering of dose in comparison EA C-GP gels which is quite significant. Together, these results indicate that the bioavailability of ellagic acid can be improved by subcutaneous formulations administered as simple EA or EA nps.