151 research outputs found
Oral amphotericin B : the journey from bench to market
Since the 1950s, amphotericin B (AmB) has been used in the clinical practice to treat systemic fungal infections and leishmaniasis, a neglected parasitic disease that can be fatal if left untreated. Fungizone® (a micellar dispersion) was the "gold standard" for more than three decades but due to the safer profile of novel lipid-based medicines (AmBisome®, Abelcet® and Amphocil®), it is now used as second-line in the developed world. Lipid-based medicines possess a more favourable safety profile (mainly lower nephrotoxicity and infusion-related side effects) allowing the administration of larger doses and therefore similar efficacy with fewer administrations. However, all formulations require parenteral administration because AmB has low oral bioavailability (0.2–0.9%) due to the precipitation of drug in aqueous media. In the last decade, strong partnerships between academia and industry has led to the development of innovative drug delivery systems able to deliver and target orally AmB in effective concentrations while reducing its nephrotoxicity and infusion-related side effects. Currently, three major platform technologies (cochleates, chitosan nanoparticles and SEDDS) that are undergoing clinical trials are discussed in this review. The pharmacokinetic and pharmacodynamic profile against visceral leishmaniasis, systemic candidiasis and aspergillosis of novel delivery systems will be discussed
Applications of 3D printing in cancer
The tumour heterogeneity and interindividual variability is a major problem when treating cancer as every patient responds in a different way to the current drug therapies. 3D printing is a tool that can hamper the issues faced in cancer patients allowing for individualisation of treatment by the production of in vitro models with micro-environments mimicking more closely real cancer conditions facilitating complex therapies. Further improvements are required, for example the development of biocompatible bioinks or need for vascularisation. The journey from bench to bedside is challenging from the regulatory point of view where the establishment of manufacturing guidelines, quality systems and safety of use and administration of personalised medicines remains unclear. This review will provide an insight in the major applications of 3D printing in cancer both in the development of in vitro cancer models as well as personalised medicines for cancer patients focused on hydrogels and therapeutic implants
Hydrophobic ion pair for the oral delivery of leucine-enkephalin
1.Purpose The global therapeutic peptides market was valued at US51.24 billion by 2027, growing at a compound annual growth rate (CAGR) of 8.7% from 2020 to 2027 (Research 2021). The peptide market is bound to grow by the increase in metabolic diseases andcancers but their translation remains challenging due to pre-systemic degradation, short plasma half-lives, and poor permeability across physiological barriers. Ion-pairing has been proposed as a method for the oraldelivery of peptides (Griesser, Hetenyi et al. 2017) as it enables increase stability to gastrointestinal enzymedegradation and enhanced permeability across physiological barriers. In this study, we explore the formationof an ion-pair of leucine-enkephalin (LENK), an endogenous opioid pentapeptide with applications as an oraltherapeutic for the treatment of pain (Lalatsa, Lee et al. 2012), Chron’s disease, and other gastrointestinalinflammatory conditions, as a strategy to enhance its oral bioavailability (Owczarek, Cibor et al. 2011). 2.Method Standard orthogenic solid phase peptide synthesis was utilized to synthesize LENK (0.5 mmole scale) (Lalatsa, Lee et al. 2012) and the peptide was obtained in high yield ( >85%) and highpurity ( >95%) as determined by HPLC and LC-MS. LENK (2.73 mmole, 1.52 mg/mL, 3mL) andsodium docusate (3mL) in deionized water (pH: 2.9) were mixed at different molar ratio (1:1,1:3, 1:5 respectively) to understand optimal ratio for pair formation and vortexed over 1 minute prior centrifugation or ultracentrifugation for 90 minutes at 4oC at 40,000 rpm (Hitachi Ultracentrifuge CP1000 NX). The supernatant was separated and the pellet was frozen withliquid nitrogen and lyophilized for 24 hours (Teslar, -50oC, 0.2mbar pressure). The LENK content was characterized by a previously validated HPLC method (Lalatsa, Lee et al. 2012). Intestinal fluid (50mM phosphate buffer, pH 6.6) was prepared from excised mouse intestine(C57BL/6, 8 weeks old, male) as previously described and characterized for protein contentusing the Bradford assay and diluted (1mg mL) (Lalatsa, Lee et al. 2012). Stability studies (37oC, 50 rpm) were undertaken and the remaining LENK was analyzed using HPLC after dilution in ice-cold acetonitrile (1:1) and centrifugation. Permeability studies across a Caco-2 cell monolayer were undertaken for LENK, the ion-paired LENK, and antipyrine with FITC dextran (3-5 kDa) as an internal control as previously described (Hubatsch, Ragnarsson et al. 2007). Caco-2 seed density was 10,000 cells/cm in this experiment. 3.Results The 1:1 and the 1:5 ratios resulted in low ion-pairing yields of 37% and 19%. The optimal ratio for pairing was identified to be 1:3 which resulted in an ion-pairing yield of 56% and this ratio was further tested in stability and permeability studies. Intestinal wash was selected as it more closely describes in vivo data scenarios (McConnell, Basit et al. 2008). LENK degraded rapidly in the intestinal wash (< 60 minutes) while the ion pair showed a 3.5-fold increase in half-life and showed levels that were significantly different after the first initial 10 minutes (Student t-test, p< 0.05) (Figure 1). Permeability across the Caco-2 cells indicate a trend for higher uptake for ion-pair LENK, but due to low TEER values obtained in our experiments due to low cell seed density (Figure 2). 4.Conclusion Ion-paired LENK has shown a significant enhancement in oral gastrointestinal stability and further studies are underway to assess its oral bioavailability across Caco-2 monolayers. Combining ion-pair technology with solid state or additively manufactured formulations can enable the production of an oral LENK formulation for the treatment of pain and inflammatory diseases such as Chron’s disease
Applying loop-mediated isothermal amplification (LAMP) in the diagnosis of malaria, leishmaniasis and trypanosomiasis as point-of-care tests (POCTs)
One of the main objectives of the WHO is controlling transmission of parasitic protozoa vector- borne diseases. A quick and precise diagnosis is critical in selecting the optimal therapeutic regime that avoids unnecessary treatments and the emergence of resistance. Molecular assays based on Loop- Mediated Isothermal Amplification (LAMP) techniques are a good alternative to light microscopy and antigen-based rapid diagnostic tests in developing countries, since they allow for a large amount of genetic material generated from a few copies of DNA, and use primers that lead to high sensitivity and specificity, while the amplification process can be performed in isothermal conditions without the need of sophisticated equipment to interpret the results. In this review, the main advances in the development of LAMP assays for the diagnosis of malaria, leishmaniasis and Chagas' disease are discussed as well as the feasibility of their implementation in developing countries and use as point- of-care diagnostic tests
Continuous microfluidic manufacture of cocrystals using 3D printed chips coupled with spray coating
Cocrystals have emerged as a promising strategy to improve the physicochemical properties of active pharmaceutical ingredients (APIs) by forming a new crystalline phase from two or more components. Particle size and morphology control are key quality attributes for cocrystal medicinal products. The needle-shaped morphology is often considered high risk and complex in the manufacture of solid dosage forms. Co-crystal particle engineering requires advanced methodologies to ensure high-purity cocrystals with improved soubility and bioavailability and with optimal crystal habit for industrial manufacturing. In this study, 3D-printed microfluidic chips were used to control the cocrystal habit and polymorphism of the sulfadimidine (SDM): 4-aminosalicylic acid (4ASA) cocrystal. The addition of PVP in the aqueous phase during mixing resulted in a high-purity cocrystal (with no traces of the individual components), while it also inhibited the growth of needle-shaped crystals. When mix-tures were prepared at the macroscale, PVP was not able to control the crystal habit and impurities of individual mixture components remained, indicating that the micro-fluidic device allowed for a more homogenous and rapid mixing process controlled by the flow rate and the high surface-to-volume ratios of the microchannels. Continuous manufacturing of SDM:4ASA cocrystals coated on beads was successfully implement-ed when the microfluidic chip was connected in line to a fluidized bed allowing co-crystal formulation generation by mixing
Designing fast-dissolving orodispersible films of amphotericin B for oropharyngeal candidiasis
Amphotericin B possesses high activity against Candida spp. with low risk of resistance. However, Amphotericin B's high molecular weight compared to other antifungal drugs, such as miconazole and clotrimazole, and poor water solubility hampers its efficacy at the physiological conditions of the oropharyngeal cavity (saliva pH, limited volume for dissolution) and thereby limits its clinical use in oropharyngeal candidiasis. We have prepared fast-dissolving orodispersible films with high loading (1% w/w) using solvent casting that enables amphotericin B to remain solubilised in saliva in equilibrium between the monomeric and dimeric states, and able to produce a local antifungal effect. Optimisation of the amphotericin B-loaded orodispersible films was achieved by quality by design studies combining dextran and/or maltodextrin as dextrose-derived-polymer film formers with cellulose-derived film formers (hydroxypropylmethyl/hydroxypropyl cellulose in a 1:4 weight ratio), sorbitol for taste masking, microcrystalline cellulose (Avicel 200) or microcrystalline cellulose-carboxymethylcellulose sodium (Avicel CL-611) for enhancing the mechanical strength of the film, and polyethylene glycol 400 and glycerol (1:1 w/w) as plasticizers. The optimised amphotericin B orodispersible films (containing 1% AmB, 25% dextran, 25% maltodextrin, 5% sorbitol, 10% Avicel 200, 10% polyethylene glycol 400, 10% glycerol, 3% hydroxypropylmethyl cellulose acetate succinate, 12% hydroxypropyl cellulose) possessed a fast disintegration time (60 ± 3 s), quick release in artificial saliva (>80% in 10 min), high burst strength (2190 mN mm) and high efficacy against several Candida spp. (C. albicans, C. parapsilosis and C. krusei) (>15 mm inhibition halo). Amphotericin B orodispersible films are stable for two weeks at room temperature (25° C) and up to 1 year in the fridge. Although further toxicological and in vivo efficacy studies are required, this novel Amphotericin B orodispersible films is a promising, physicochemically stable formulation with potential wide application in clinical practice, especially for immunocompromised patients suffering from oropharyngeal candidiasis
Microfluidic manufacture of lipid-based nanomedicines
Nanoparticulate technologies have revolutionised drug delivery allowing for passive and active targeting, altered biodistribution, control drug release (temporospatial or triggered), enhanced sta-bility, improved solubilisation capacity, reduction of dose and adverse effects. However, their manufacture remains immature, and challenges exist in industrial scale due to high batch-to-batch variability hindering their clinical translation. Lipid-based nanomedicines remain the most-widely approved nanomedicines and their current manufacturing methods remain discontinuous and face several problems such as high batch-to-batch variability affecting the critical quality attributes (CQAs) of the product, laborious multi-step processes, need for an expert workforce and are not easily amenable to industrial scale-up involving typically a complex process control. Several tech-niques have emerged in recent years for nanomedicine manufacture, but a paradigm shift occurred when microfluidic strategies able to mix fluids in channels with dimensions of tens of micrometers and small volumes of liquid reagents in a highly controlled manner to form nanoparticles with tunable and reproducible structure are employed. In this review, we summarize the recent ad-vancements in the manufacturing of lipid-based nanomedicines using microfluidics with particular emphasis on the parameters that govern the control of CQAs of final nanomedicines. The impact of microfluidic environments on formation dynamics of nanomaterials, and the application of mi-crodevices as platforms for nanomaterial screening were also discussed
Interaction with touchscreen smartphones in patientswith essential tremor and healthy individuals.
tremorAbstractIntroduction: Smartphone use in biomedical research is becoming more prevalent in differ-ent clinical settings. We performed a pilot study to obtain information on smartphone use bypatients with essential tremor (ET) and healthy controls, with a view to determining whetherperformance of touchscreen tasks is different between these groups and describing touchscreeninteraction factors.Method: A total of 31 patients with ET and 40 sex- and age-matched healthy controls com-pleted a descriptive questionnaire about the use of smartphones. Participants subsequentlyinteracted with an under-development Android application, and performed 4 tests evaluatingtypical touchscreen interaction gestures; each test was performed 5 times.Result: The type of smartphone use and touchscreen interaction were not significantly differ-ent between patients and controls. Age and frequency of smartphone use are key factors intouchscreen interaction.Conclusion: Our results support the use of smartphone touchscreens for research into ET,although further studies are required.pre-print1030 K
Tuning the transdermal delivery of hydroquinone upon formulation with novel permeation enhancers
Hydroquinone (HQ) is an anti-hyperpigmentation agent with poor physicochemical stability. HQ formulations are currently elaborated by compounding in local pharmacies. Variability in the characteristics of HQ topical formulations can lead to remarkable di erences in terms of their stability, efficacy, and toxicity. Four different semisolid O/Wformulations with 5% HQ were prepared using: (i) Beeler's base plus antioxidants (F1), (ii) Beeler's base and dimethyl isosorbide (DMI) as solubiliser (F2), (iii) olive oil and DMI (F3), and (iv) Nourivan®, a skin-moisturising and antioxidant base, along with DMI (F4). Amongst the four formulations, F3 showed the greatest physicochemical stability with less tendency to coalescence but with marked chromatic aberrations. An inverse correlation was established by multivariate analysis between the mean droplet size in volume and the steady-state flux, which explains why F3, with the smallest droplet size and the most hydrophobic excipients, exhibited the highest permeation across both types of membranes with enhancement ratios of 2.26 and 5.67-fold across Strat-M® and mouse skin, respectively, compared to F1. It is crucial to understand how the HQ is formulated, bearing in mind that the use of different excipients can tune the transdermal delivery of HQ significantly
Engineering 3D printed microfluidic chips for the fabrication of nanomedicines
Currently, there is an unmet need to manufacture nanomedicines in a continuous and controlled manner. Three-dimensional (3D) printed microfluidic chips are an alternative to conventional PDMS chips as they can be easily designed and manufactured to allow for customized designs that are able to reproducibly manufacture nanomedicines at an affordable cost. The manufacturing of microfluidic chips using existing 3D printing technologies remains very challenging because of the intricate geometry of the channels. Here, we demonstrate the manufacture and characterization of nifedipine (NFD) polymeric nanoparticles based on Eudragit L-100 using 3D printed microfluidic chips with 1 mm diameter channels produced with two 3D printing techniques that are widely available, stereolithography (SLA) and fuse deposition modeling (FDM). Fabricated polymeric nanoparticles showed good encapsulation efficiencies and particle sizes in the range of 50–100 nm. SLA chips possessed better channel resolution and smoother channel surfaces, leading to smaller particle sizes similar to those obtained by conventional manufacturing methods based on solvent evaporation, while SLA manufactured nanoparticles showed a minimal burst effect in acid media compared to nanoparticles fabricated with FDM chips. Three-dimensional printed microfluidic chips are a novel and easily amenable cost-effective strategy to allow for customization of the design process for continuous manufacture of nanomedicines under controlled conditions, enabling easy scale-up and reducing nanomedicine development times, while maintaining high-quality standards
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