Amphotericin B in the Era of New Antifungals: Where Will It Stand?

Amphotericin B (AmB) has long stood as a cornerstone in the treatment of invasive fungal infections (IFIs), especially among immunocompromised patients. However, the landscape of antifungal therapy is evolving. New antifungal agents, boasting novel mechanisms of action and better safety profiles, are entering the scene, presenting alternatives to AmB's traditional dominance. This shift, prompted by an increase in the incidence of IFIs, the growing demographic of immunocompromised individuals, and changing patterns of fungal resistance, underscores the continuous need for effective treatments. Despite these challenges, AmB's broad efficacy and low resistance rates maintain its essential status in antifungal therapy. Innovations in AmB formulations, such as lipid complexes and liposomal delivery systems, have significantly mitigated its notorious nephrotoxicity and infusion-related reactions, thereby enhancing its clinical utility. Moreover, AmB's efficacy in treating severe and rare fungal infections and its pivotal role as prophylaxis in high-risk settings highlight its value and ongoing relevance. This review examines AmB's standing amidst the ever-changing antifungal landscape, focusing on its enduring significance in current clinical practice and exploring its potential future therapeutic adaptations.

Nanotechnology-based fungal detection and treatment: current status and future perspective

Fungal infections impose a significant impact on global health and encompass major expenditures in medical treatments. Human mycoses, a fungal co-infection associated with SARS-CoV-2, is caused by opportunistic fungal pathogens and is often overlooked or misdiagnosed. Recently, there is increasing threat about spread of antimicrobial resistance in fungus, mostly in hospitals and other healthcare facilities. The diagnosis and treatment of fungal infections are associated with several issues, including tedious and non-selective detection methods, the growth of drug-resistant bacteria, severe side effects, and ineffective drug delivery. Thus, a rapid and sensitive diagnostic method and a high-efficacy and low-toxicity therapeutic approach are needed. Nanomedicine has emerged as a viable option for overcoming these limitations. Due to the unique physicochemical and optical properties of nanomaterials and newer biosensing techniques, nanodiagnostics play an important role in the accurate and prompt differentiation and detection of fungal diseases. Additionally, nano-based drug delivery techniques can increase drug permeability, reduce adverse effects, and extend systemic circulation time and drug half-life. This review paper is aimed at highlighting recent, promising, and unique trends in nanotechnology to design and develop diagnostics and treatment methods for fungal diseases.

Revisiting the in-vitro and in-vivo considerations for in-silico modelling of complex injectable drug products

Complex injectable drug products (CIDPs) have often been developed to modulate the pharmacokinetics along with efficacy for therapeutic agents used for remediation of chronic disorders. The effective development of CIDPs has exhibited complex kinetics associated with multiphasic drug release from the prepared formulations. Consequently, predictability of pharmacokinetic modelling for such CIDPs has been difficult and there is need for advanced complex computational models for the establishment of accurate prediction models for in-vitro-in-vivo correlation (IVIVC). The computational modelling aims at supplementing the existing knowledge with mathematical equations to develop formulation strategies for generation of predictable and discriminatory IVIVC. Such an approach would help in reduction of the burden of effect of hidden factors on preclinical to clinical translations. Computational tools like physiologically based pharmacokinetics (PBPK) modelling have combined physicochemical and physiological properties along with IVIVC characteristics of clinically used formulations. Such techniques have helped in prediction and understanding of variability in pharmacodynamic parameters of potential generic products to clinically used formulations like Doxil®, Ambisome®, Abraxane® in healthy and diseased population using mathematical equations. The current review highlights the important formulation characteristics, in-vitro, preclinical in-vivo aspects which need to be considered while developing a stimulatory predictive PBPK model in establishment of an IVIVC and in-vitro-in-vivo relationship (IVIVR).

Hyaluronic acid-Amphotericin B Nanocomplexes: a Promising Anti-Leishmanial Drug Delivery System

The development of an effective amphotericin B (AmB) formulation to replace actual treatments available for leishmaniasis, which present serious drawbacks, is a challenge. Here we report the development of hyaluronic...

Cyclodextrins-modified metallic nanoparticles for effective cancer therapy

Cancer, a disease of unknown origin is the second most common reason of death worldwide after heart attacks and therefore is a major threat to human beings. Currently, chemotherapy is the only approach for delivering anti-cancer drugs but shows severe systemic toxicities such as alopecia, loss of appetite, anemia, gastric irritation, neurotoxicity and nephrotoxicity. Additionally, chemotherapeutics fails to achieve the expected therapeutic outcome due to their limited solubility, in-vivo instability and lack of targeting efficiency. Encapsulating drugs in metallic nanoparticles like gold, silver and metal oxides (magnetic) help to overcome limitations of chemotherapy and transports anti-cancer drugs effectively at the targeted site due to the advantages such as optimal size, surface morphology, higher conductivity and in-vivo stability. Moreover, these metals can be triggered externally using NIR radiations or magnetic field thereby improving the drug release kinetics. Some frequently used chemotherapeutic agents such as doxorubicin, paclitaxel, methotrexate, etc. degrade rapidly due to their hydrophobic nature and show in-vivo instability. Cyclodextrin offers structural compatibility for encapsulating such hydrophobic drugs and improves their loading capacity, solubility and stability without showing any systemic toxicities. Therefore, researchers designed cyclodextrin-complexed metallic nanoparticles as a novel platform to overcome pitfalls of conventional chemotherapy like gastric irritation, hair loss, neurotoxicity, etc. This review article provides detail insight of metallic nanocarriers containing cyclodextrin-encapsulated anti-cancer agents for effective cancer therapy. It can be concluded that this novel approach holds a great potential for clinical application in cancer diagnosis, treatment with minimum toxicity and maximum efficacy.

Correlation between Biophysical Properties of Niosomes Elaborated with Chloroquine and Different Tensioactives and Their Transfection Efficiency

Lipid nanocarriers, such as niosomes, are considered attractive candidates for non-viral gene delivery due to their suitable biocompatibility and high versatility. In this work, we studied the influence of incorporating chloroquine in niosomes biophysical performance, as well as the effect of non-ionic surfactant composition and protocol of incorporation in their biophysical performance. An exhaustive comparative evaluation of three niosome formulations differing in these parameters was performed, which included the analysis of their thermal stability, rheological behavior, mean particle size, dispersity, zeta potential, morphology, membrane packing capacity, affinity to bind DNA, ability to release and protect the genetic material, buffering capacity and ability to escape from artificially synthesized lysosomes. Finally, in vitro biological studies were, also, performed in order to determine the compatibility of the formulations with biological systems, their transfection efficiency and transgene expression. Results revealed that the incorporation of chloroquine in niosome formulations improved their biophysical properties and the transfection efficiency, while the substitution of one of the non-ionic surfactants and the phase of addition resulted in less biophysical variations. Of note, the present work provides several biophysical parameters and characterization strategies that could be used as gold standard for gene therapy nanosystems evaluation.

Molecular Mechanism of Ultrasound-Induced Structural Defects in Liposomes: A Nonequilibrium Molecular Dynamics Simulation Study

The use of ultrasound in combination with liposomes is a promising approach to improve drug delivery. To achieve an optimal drug release rate, it is important to understand how ultrasound induces pathways on the liposome surface where drugs can be released from the liposome. To this end, we carry out large-scale ultrasound-induced molecular dynamics simulations for three single lipid component liposomes formed from the commonly used phospholipids: 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dipalmitoylphosphatidylcholine (DPPC), or phosphatidylcholine (POPC). The results show that ultrasound induces the detachment of two leaflets of the DOPC surface, suggesting that the drug release pathway may be through the low lipid packing areas on the stretched surface. In contrast, ultrasound induces pore formation on the surface of DPPC and DOPC, where drugs could escape from the liposomes. While the leaflet detachment and transient pore formation are the mechanisms of DOPC and DPPC, respectively, in both liquid-ordered and liquid-disordered phases, the leaflet detachment mechanism is switched to the transient pore formation mechanism on going from the liquid-ordered phase to the liquid-disordered phase in the POPC liposome. By adding 30% mol cholesterol, the leaflet detachment mechanism is observed in all liposomes. We found that the molecular origin that determines a mechanism is the competition between the intraleaflet and interleaflet interacting energy of lipids. The connection to experimental and theoretical modeling is discussed in some detail.

Analytical method development and comparability study for AmBisome® and generic Amphotericin B liposomal products

Liposomal Amphotericin B, known as AmBisome®, is a life-saving antifungal product that sold $407 million in 2019. AmBisome® has a rather complex physical structure in that Amphotericin B (AmpB) forms a stable ionic complex with the lipid bilayer to maintain AmBisome®'s low toxicity and high stability in systemic circulation. Failed attempts to reproduce AmBisome®'s precise structure has resulted in faster drug release and higher toxicity both in vitro and in vivo. In this study, we established several analytical methodologies to quantify liposomal AmpB components, characterize thermal properties of the liposome, and determine particle size distribution, AmpB aggregation state, and drug release kinetics. We applied these methodologies together with in vitro hemolytic potential and antifungal activity tests to characterize multiple lots of AmBisome® and two generic products approved in India, Phosome® and Amphonex®. We also used Fungizone®, a micellar AmpB formulation, and "leaky" AmpB liposomes as negative controls. Our results showed that Phosome® and Amphonex® were both similar to AmBisome®, while Fungizone® and 'leaky" liposomes exhibited differences in both thermal properties and AmpB aggregation state, leading to faster drug release and higher toxicity. Due to the increased interest of the pharmaceutical industry in making generic AmBisome® and the lack of standard analytical methods to characterize liposomal AmpB products, the methodologies described here are valuable for the development of generic liposomal AmpB products.

Therapies and Vaccines Based on Nanoparticles for the Treatment of Systemic Fungal Infections

Treatment modalities for systemic mycoses are still limited. Currently, the main antifungal therapeutics include polyenes, azoles, and echinocandins. However, even in the setting of appropriate administration of antifungals, mortality rates remain unacceptably high. Moreover, antifungal therapy is expensive, treatment periods can range from weeks to years, and toxicity is also a serious concern. In recent years, the increased number of immunocompromised individuals has contributed to the high global incidence of systemic fungal infections. Given the high morbidity and mortality rates, the complexity of treatment strategies, drug toxicity, and the worldwide burden of disease, there is a need for new and efficient therapeutic means to combat invasive mycoses. One promising avenue that is actively being pursued is nanotechnology, to develop new antifungal therapies and efficient vaccines, since it allows for a targeted delivery of drugs and antigens, which can reduce toxicity and treatment costs. The goal of this review is to discuss studies using nanoparticles to develop new therapeutic options, including vaccination methods, to combat systemic mycoses caused by Candida sp., Cryptococcus sp., Paracoccidioides sp., Histoplasma sp., Coccidioides sp., and Aspergillus sp., in addition to providing important information on the use of different types of nanoparticles, nanocarriers and their corresponding mechanisms of action.

Preclinical Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Antifungal Activity of Liposomal Amphotericin B

The improved safety profile and antifungal efficacy of liposomal amphotericin B (LAmB) compared to conventional amphotericin B deoxycholate (DAmB) is due to several factors including, its chemical composition, rigorous manufacturing standards, and ability to target and transit through the fungal cell wall. Numerous preclinical studies have shown that LAmB administered intravenously distributes to tissues frequently infected by fungi at levels above the minimum inhibitory concentration (MIC) for many fungi. These concentrations can be maintained from one day to a few weeks, depending upon the tissue. Tissue accumulation is dose-dependent with drug clearance occurring most rapidly from the brain and slowest from the liver and spleen. LAmB localizes in lung epithelial lining fluid, within liver and splenic macrophages and in kidney distal tubules. LAmB has been used successfully in therapeutic and prophylactic animal models to treat many different fungal pathogens, significantly increasing survival and reducing tissue fungal burden.

Opportunities and challenges in commercial pharmaceutical liposome applications

In the 1980s, the center of entrepreneurial activity for the application of liposome science to medicine took the form of a company called Vestar Inc. (which became NeXstar Pharmaceuticals Inc., and eventually a division of Gilead Sciences, with merger and acquisition activity). This company was formed from science initially developed at the California Institute of Technology and the City of Hope, and involving several other local academic and treatment centers. This company eventually produced two commercial liposomal therapeutics, and created a particular paradigm of formulation goals, formulation development, characterization, and production unique among the set of companies that emerged around the same time. A number of clinical candidates were also developed, but failed to achieve commercialization. Nevertheless, several of these provide still relevant lessons and guidance for the field. Key adaptations of this technology to lower cost applications have also been carried out and are examined.

Lipid Systems for the Delivery of Amphotericin B in Antifungal Therapy

Amphotericin B (AmB), a broad-spectrum polyene antibiotic in the clinic for more than fifty years, remains the gold standard in the treatment of life-threatening invasive fungal infections and visceral leishmaniasis. Due to its poor water solubility and membrane permeability, AmB is conventionally formulated with deoxycholate as a micellar suspension for intravenous administration, but severe infusion-related side effects and nephrotoxicity hamper its therapeutic potential. Lipid-based formulations, such as liposomal AmB, have been developed which significantly reduce the toxic side effects of the drug. However, their high cost and the need for parenteral administration limit their widespread use. Therefore, delivery systems that can retain or even enhance antimicrobial efficacy while simultaneously reducing AmB adverse events are an active area of research. Among those, lipid systems have been extensively investigated due to the high affinity of AmB for binding lipids. The development of a safe and cost-effective oral formulation able to improve drug accessibility would be a major breakthrough, and several lipid systems for the oral delivery of AmB are currently under development. This review summarizes recent advances in lipid-based systems for targeted delivery of AmB focusing on non-parenteral nanoparticulate formulations mainly investigated over the last five years and highlighting those that are currently in clinical trials.

In Vitro and In Vivo Exposure-Effect Relationship of Liposomal Amphotericin B against Aspergillus fumigatus

In vitro pharmacokinetic/pharmacodynamic data of liposomal amphotericin B (L-AMB) were compared with animal data from neutropenic and nonneutropenic models of azole-susceptible and azole-resistant invasive aspergillosis. L-AMB was equally effective. The in vitro fC _max (maximum concentration of free drug)/MIC ratio associated with 50% of maximal activity was 0.31 (0.29 to 0.33), similar to that in neutropenic but not nonneutropenic mice (0.11 [0.06 to 0.20]). Simulation analysis indicated that standard L-AMB doses (1 to 3 mg/kg) are adequate for nonneutropenic patients, but higher doses (7.5 to 10 mg/kg) may be required for neutropenic patients for Aspergillus fumigatus isolates with MICs of 0.5 to 1 mg/liter.

The care and feeding of a commercial liposomal product: liposomal amphotericin B (AmBisome®)

AmBisome (liposomal amphotericin B) is among the earliest approved liposomal therapeutics, and has been in commercial use since the early 1990s. This review provides examples of non-clinical, regulatory, clinical label expansion, adverse event management, and supply chain control reflecting the real world challenges of a commercial liposomal therapeutic. We review examples of post-approval clinical development in severe lung infections, development of US and European guidance documents around liposomal therapeutics, the creation of a suitable placebo for blinded clinical trials, response to findings of a possible new category of adverse event (what turned out to be pseudohyperphosphatemia), challenges in handling the finished product in a setting with high risk of exposure of the product to temperatures outside of the established label storage conditions, and elements of continuingly increased aseptic processing requirements for manufacturing.

Efficacy, Biodistribution, and Nephrotoxicity of Experimental Amphotericin B-Deoxycholate Formulations for Pulmonary Aspergillosis

An experimental micellar formulation of 1:1.5 amphotericin B-sodium deoxycholate (AMB:DCH 1:1.5) was obtained and characterized to determine its aggregation state and particle size. The biodistribution, nephrotoxicity, and efficacy against pulmonary aspergillosis in a murine model were studied and compared to the liposomal commercial formulation of amphotericin B after intravenous administration. The administration of 5 mg/kg AMB:DCH 1:1.5 presented 2.8-fold-higher lung concentrations (18.125 ± 3.985 μg/g after 6 daily doses) and lower kidney exposure (0.391 ± 0.167 μg/g) than liposomal commercial amphotericin B (6.567 ± 1.536 and 5.374 ± 1.157 μg/g in lungs and kidneys, respectively). The different biodistribution of AMB:DCH micelle systems compared to liposomal commercial amphotericin B was attributed to their different morphologies and particle sizes. The efficacy study has shown that both drugs administered at 5 mg/kg produced similar survival percentages and reductions of fungal burden. A slightly lower nephrotoxicity, associated with amphotericin B, was observed with AMB:DCH 1:1.5 than the one induced by the liposomal commercial formulation. However, AMB:DCH 1:1.5 reached higher AMB concentrations in lungs, which could represent a therapeutic advantage over liposomal commercial amphotericin B-based treatment of pulmonary aspergillosis. These results are encouraging to explore the usefulness of AMB:DCH 1:1.5 against this disease.

Zinc oxide nanoparticles in predicted environmentally relevant concentrations leading to behavioral impairments in male swiss mice

Although the potential neurotoxic effects from the exposure to zinc oxide nanoparticles (ZnO NPs) on humans and on experimental models have been reported in previous studies, the effects from the exposure to environmentally relevant concentrations of them remain unclear. Thus, the aim of the present study is to investigate the effects from the exposure to environmentally relevant concentrations of ZnO NPs on the behavior of male Swiss mice. The animals were daily exposed to environmentally relevant concentrations of ZnO NPs (5.625×10^-5mgkg^-1) at toxic level (300mgkg^-1) through intraperitoneal injection for five days; a control group was set for comparison purposes. Positive control groups (clonazepam and fluoxetine) and a baseline group were included in the experimental design to help analyzing the behavioral tests (open field, elevated plus maze and forced swim tests). Although we did not observe any behavioral change in the animals subjected to the elevated plus maze and forced swim tests, our data evidence the anxiogenic behavior of animals exposed to the two herein tested ZnO NPs concentrations in the open field test. The animals stayed in the central part of the apparatus and presented lower locomotion ratio in the central quadrants/total of locomotion during this test. It indicates that the anxiogenic behavior was induced by ZnO NP exposure, because it leads to Zn accumulation in the brain. Thus, the current study is the first to demonstrate that the predicted environmentally relevant ZnO NPs concentration induces behavioral changes in mammalian experimental models. Our results corroborate previous studies that have indicated the biological risks related to the water surface contamination by metal-based nanomaterials.

The effect of particle shape on cellular interaction and drug delivery applications of micro- and nanoparticles

Encapsulation of therapeutic agents in nanoparticles offers several benefits including improved bioavailability, site specific delivery, reduced toxicity and in vivo stability of proteins and nucleotides over conventional delivery options. These benefits are consequence of distinct in vivo pharmacokinetic and biodistribution profile of nanoparticles, which is dictated by the complex interplay of size, surface charge and surface hydrophobicity. Recently, particle shape has been identified as a new physical parameter which has exerted tremendous impact on cellular uptake and biodistribution, thereby in vivo performance of nanoparticles. Improved therapeutic efficacy of anticancer agents using non-spherical particles is the recent development in the field. Additionally, immunological response of nanoparticles was also altered when antigens were loaded in non-spherical nanovehicles. The apparent impact of particle shape inspired the new research in the field of drug delivery. The present review therefore details the research in this field. The review focuses on methods of fabrication of particles of non-spherical geometries and impact of particle shape on cellular uptake, biodistribution, tumor targeting and production of immunological responses.

In Vivo Biomarker Analysis of the Effects of Intranasally Dosed PC945, a Novel Antifungal Triazole, on Aspergillus fumigatus Infection in Immunocompromised Mice

PC945 is a novel triazole optimized for lung delivery, and the objective of this study is to determine the effects of intranasally dosed PC945 on Aspergillus fumigatus infection and associated biomarkers in immunocompromised mice. PC945, posaconazole, or voriconazole was administered intranasally once daily on days 0 to 3 (early intervention) or days 1 to 3 (late intervention) postinfection in temporarily neutropenic A/J mice infected intranasally with A. fumigatus, and bronchoalveolar lavage fluid (BALF) and serum were collected on day 3. The effects of extended prophylaxis treatment (daily from days −7 to +3 or days −7 to 0) were also compared with those of the shorter treatment regimens (days −1 to +3 or days −1 and 0). Early and late interventions with PC945 (2.8 to 350 μg/mouse; approximately 0.11 to ∼14 mg/kg of body weight) were found to inhibit lung fungal loads and to decrease the concentrations of galactomannan (GM) in both BALF and serum as well as several biomarkers in BALF (interferon gamma [IFN-γ], interleukin-17 [IL-17], and malondialdehyde) and serum (tumor necrosis factor alpha [TNF-α] and IL-6) in a dose-dependent manner and were >3- and >47-fold more potent than intranasally dosed posaconazole and voriconazole, respectively. Furthermore, extended prophylaxis with low-dose PC945 (0.56 μg/mouse; 0.022 mg/kg) was found to inhibit fungal loads and to decrease the concentrations biomarkers more potently than did the shorter treatment regimens. Thus, PC945 dosed intranasally once daily showed potent antifungal effects, and the effects of PC945 accumulated upon repeat dosing and were persistent. Therefore, PC945 has the potential to be a novel inhaled therapy for the treatment of A. fumigatus infection in humans.

Tissue pharmacokinetics and pharmacodynamics of AmBisome® (L-AmBis) in uninfected and infected animals and their effects on dosing regimens

By selecting a unique combination of lipids and amphotericin B, the liposome composition for AmBisome® (L-AmBis) has been optimized resulting in a formulation that is minimally toxic, targets to fungal cell walls, and distributes into and remains for days to weeks in various host tissues at drug levels above the MIC for many fungi. Procedures have been standardized to ensure that large scale production of the drug retains the drug's low toxicity profile, favorable pharmacokinetics and antifungal efficacy. Tissue accumulation and clearance with single or multiple intravenous administration is similar in uninfected and infected animal species, with tissue accumulation being dose-dependent and the liver and spleen retaining the most drug. The efficacy in animals appears to be correlated with drug tissue levels although the amount needed in a given organ varies depending upon the type of infection. The long-term tissue retention of bioactive L-AmBis in different organs suggests that for some indications, prophylactic and intermittent drug dosing would be efficacious reducing the cost and possible toxic side-effects. In addition, preliminary preclinical studies using non-intravenous routes of delivery, such as aerosolized L-AmBis, catheter lock therapy, and intravitreal administration, suggest that alternative routes could possibly provide additional therapeutic applications for this antifungal drug.

Application of a low molecular weight antifungal protein from Penicillium chrysogenum (PAF) to treat pulmonary aspergillosis in mice

PAF, a small antifungal protein from Penicillium chrysogenum, inhibits the growth of several pathogenic filamentous fungi, including members of the Aspergillus genus. PAF has been proven to have no toxic effects in vivo in mice by intranasal application. To test its efficacy against invasive pulmonary aspergillosis (IPA), experiments were carried out in mice suffering from IPA. Adult mice were immunosuppressed and then infected with Aspergillus fumigatus. After stable infection, the animals were inoculated with PAF intranasally at a concentration of 2.7 mg/kg twice per day. At this concentration—which is highly toxic in vitro to A. fumigatus—the mortality of the animals was slightly delayed but finally all animals died. Histological examinations revealed massive fungal infections in the lungs of both PAF-treated and untreated animal groups. Because intranasally administered PAF was unable to overcome IPA, modified and combined therapies were introduced. The intraperitoneal application of PAF in animals with IPA prolonged the survival of the animals only 1 day. Similar results were obtained with amphotericin B (AMB), with PAF and AMB being equally effective. Combined therapy with AMB and PAF—which are synergistic in vitro—was found to be more effective than either AMB or PAF treatment alone. As no toxic effects of PAF in mammals have been described thus far, and, moreover, there are so far no A. fumigatus strains with reported inherent or acquired PAF resistance, it is worth carrying out further studies to introduce PAF as a potential antifungal drug in human therapy.

Longitudinal, in vivo assessment of invasive pulmonary aspergillosis in mice by computed tomography and magnetic resonance imaging

Invasive aspergillosis is an emerging threat to public health due to the increasing use of immune suppressive drugs and the emergence of resistance against antifungal drugs. To deal with this threat, research on experimental disease models provides insight into the pathogenesis of infections caused by susceptible and resistant Aspergillus strains and by assessing their response to antifungal drugs. However, standard techniques used to evaluate infection in a preclinical setting are severely limited by their invasive character, thereby precluding evaluation of disease extent and therapy effects in the same animal. To enable non-invasive, longitudinal monitoring of invasive pulmonary aspergillosis in mice, we optimized computed tomography (CT) and magnetic resonance imaging (MRI) techniques for daily follow-up of neutropenic BALB/c mice intranasally infected with A. fumigatus spores. Based on the images, lung parameters (signal intensity, lung tissue volume and total lung volume) were quantified to obtain objective information on disease onset, progression and extent for each animal individually. Fungal lung lesions present in infected animals were successfully visualized and quantified by both CT and MRI. By using an advanced MR pulse sequence with ultrashort echo times, pathological changes within the infected lung became visually and quantitatively detectable at earlier disease stages, thereby providing valuable information on disease onset and progression with high sensitivity. In conclusion, these non-invasive imaging techniques prove to be valuable tools for the longitudinal evaluation of dynamic disease-related changes and differences in disease severity in individual animals that might be readily applied for rapid and cost-efficient drug screening in preclinical models in vivo.

Comparison between liposomal formulations of amphotericin B

Given the clinical success of commercial amphotericin B lipid products, investigators have begun making generic formulations of liposomal amphotericin B. Generic medicines are an attractive approach to help decrease the cost and accessibility to healthcare, provided that appropriate studies are performed to ensure bioequivalence with the parent product. This is of particular concern for liposomal drugs such as amphotericin B where liposomes are used as a carrier system to reduce the toxicity of the active agent. A favorable therapeutic profile for this form of the drug has to include the proper chemical composition along with strictly controlled manufacturing processes. Studies have shown that a comparison of liposomal amphotericin B products with different or the same chemical compositions, using different methods of production, will vary in size, and have significantly dissimilar in vitro and in vivo toxicities along with reduced efficacy. These results underscore the importance of establishing appropriate bioequivalence testing for liposome products to ensure uniformity of their therapeutic index.