RESUMO
Uveitis is a group of inflammatory ocular pathologies. Endotoxin-Induced Uveitis (EIU) model represent a well-known model induced by administration of Lipopolysaccharide (LPS). The aim is to characterize two models of EIU through two routes of administration with novel noninvasive imaging techniques. 29 rats underwent Intraocular Pressure (IOP) measurements, Optical Coherence Tomography (OCT), proteomic analysis, and Positron Emission Tomography and Computed Tomography (PET/CT). Groups included healthy controls (C), BSS administered controls (Ci), systemically induced EIU with LPS (LPSs), and intravitreally induced EIU with LPS (LPSi) for IOP, OCT, and proteomic studies. For 18F-FDG PET/CT study, animals were divided into FDG-C, FDG-LPSs and FDG-LPSi groups and scanned using a preclinical PET/CT system. LPSi animals exhibited higher IOP post-induction compared to C and LPSs groups. LPSi showed increased cellular infiltrate, fibrotic membranes, and iris inflammation. Proinflammatory proteins were more expressed in EIU models, especially LPSi. PET/CT indicated higher eye uptake in induced models compared to FDG-C. FDG-LPSi showed higher eye uptake than FDG-LPSs but systemic uptake was higher in FDG-LPSs due to generalized inflammation. OCT is valuable for anterior segment assessment in experimental models. 18F-FDG PET/CT shows promise as a noninvasive biomarker for ocular inflammatory diseases. Intravitreal induction leads to higher ocular inflammation. These findings offer insights for future inflammatory disease research and drug studies.
RESUMO
Anti-vascular endothelial growth factor drugs keep being the main therapy for neovascular age-related macular degeneration (AMD). Possible predictive parameters (demographic, biochemical and/or inflammatory) could anticipate short-term treatment response with ranibizumab. 46 treatment-naive patients were included in a prospective observational study. They underwent three monthly injections of intravitreal ranibizumab for neovascular AMD and the clinical examination was made at baseline and one month after the third injection. Demographic characteristics, co-morbidities and concomitant treatments were recorded at the baseline visit. Biochemical parameters, complete blood count and inflammation biomarkers were also measured at these times. Uric Acid was found to be statistically significant with a one-point difference between good and poor responders in both basal and treated patients, but only in basal parameters was statistical significance reached (p = 0.007 vs. p = 0.071 in treated patients). Cholesterol and inflammatory parameters such as white blood cell count and neutrophils were significantly reduced over time when treated with intravitreal ranibizumab. On the other hand, women seemed to have a worse prognosis for short-term response to intravitreal ranibizumab treatment. Uric acid may help identify possible non-responders before initial treatment with ranibizumab, and cholesterol and white blood cells could be good candidates to monitor short-term response to ranibizumab treatment.
RESUMO
BACKGROUND: Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in several tissues and organs causing, among others, severe eye symptoms. The high instability of cysteamine eye drops makes it difficult to develop formulations with an acceptable shelf life to be prepared in hospital pharmacy departments. Previously, a new compounded formulation of cysteamine eye drops in hyaluronic acid (HA) packaged in innovative single-dose systems was developed. METHODS: Long-term stability at -20 °C of this formulation was studied considering the content of cysteamine, pH, osmolality, viscosity, and microbiological analysis. The oxygen permeability of single-dose containers was also studied and an ocular biopermanence study was conducted in healthy volunteers measuring lacrimal stability and volume parameters. RESULTS: Data confirm that cysteamine concentration remained above 90% for 120 days, all parameters remaining within the accepted range for ophthalmic formulations. The permeability of the containers was reduced over time, while ocular biopermanence was maintained despite the freezing process and storage time. CONCLUSIONS: 0.55% cysteamine hydrochloride formulation in HA and packaged in single-dose containers preserved at -20 °C is stable for 120 days protected from light, presenting high potential for its translation into clinical practice when commercial presentations are not available.
RESUMO
Purpose: To determine whether genetic risk single nucleotide polymorphisms (SNPs) for age-related macular degeneration (AMD) influence short-term response to intravitreal ranibizumab treatment. Methods: Forty-four treatment-naive AMD patients were included in a prospective observational study. They underwent three monthly injections of intravitreal ranibizumab for neovascular AMD. After an initial clinical examination (baseline measurement), a follow-up visit was performed to determine treatment response one month after the third injection (treatment evaluation). Patients were evaluated based on ophthalmoscopy, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography. Peripheral venous blood was collected for DNA analysis at baseline visit. Patients were genotyped for single-nucleotide polymorphisms within AMD-relevant genes and classified on good or poor responders based on visual acuity, central retinal thickness, intraretinal fluid, and subretinal fluid. Results: One hundred ten AMD-associated SNPs have been analyzed. Six were found to be relevant when associated to ranibizumab treatment response. The genetic variants rs890293 (CYP2J2), rs11200638 (HTRA1), rs405509 (APOE), rs9513070 (FLT1), and rs8135665 (SLC16A8) predisposed patients to a good response, whereas rs3093077 (CRP) was associated with a poor response. FTL1, SLC16A8, and APOE were the SNPs that showed significance (P < 0.05) but did not pass Bonferroni correction. Conclusions: This is the first study that links novel polymorphisms in genes such as CRP, SCL16A8, or CYP2J2 to treatment response to ranibizumab therapy. On the other hand, HTRA1, FLT1, and APOE are linked to a good ranibizumab response. These SNPs may be good candidates for short-term treatment response biomarkers in AMD patients. However, further studies will be necessary to confirm our findings.
Assuntos
Ranibizumab , Degeneração Macular Exsudativa , Humanos , Ranibizumab/uso terapêutico , Inibidores da Angiogênese/uso terapêutico , Citocromo P-450 CYP2J2 , Fator A de Crescimento do Endotélio Vascular/genética , Acuidade Visual , Degeneração Macular Exsudativa/diagnóstico , Degeneração Macular Exsudativa/tratamento farmacológico , Degeneração Macular Exsudativa/genética , Polimorfismo de Nucleotídeo Único , Apolipoproteínas E , Injeções Intravítreas , Tomografia de Coerência Óptica , Resultado do TratamentoRESUMO
Introduction: Introduction: there is a wide variety of enteral nutrition and infant formulas preparations. When there is a need to find infomation on a product, only the infomation from industy is available. Comparison amomg products becomes then ardous. Objective: to describe the development of NEmecum as the first website that allows a directed and independent search for enteral nutrition products and infant formulas, currently available in Spain, and to evaluate the initial use of NEmecum. Methods: the structure of a database that unifies the parameters of all formulas was developed, and the nutritional composition of all formulas was analyzed. Subsequently, the main search algorithms were selected and the digital tool was codified. Intensive dissemination was performed and the impact was evaluated. The profile of users and registered centers and the use of the tool were analyzed, and its usability was evaluated using the System Usability Scale (SUS) questionnaire. Results: a free-access responsive website (http://nemecum.com) that allows searches based on pre-established search filters was obtained. This tool allows for a detailed analysis avalaible formulas in Spain by observing a wide variety of formulas with similar characteristics. The dissemination campaign managed to increase its use exponentially, currently reaching 1,370 users and 79 registered centers. Usability was rated as excellent. Conclusion: the development of the NEmecum represents a valuable tool in the search and consultation of the characteristics of enteral nutrition formulas and infant preparations.
Introducción: Introducción: existe una amplia variedad de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles. La consulta de información relacionada debe hacerse en las herramientas propias de cada laboratorio, lo que dificulta la visión crítica y la comparativa entre las mismas. Objetivo: describir el desarrollo de NEmecum como la primera web que permite realizar una búsqueda dirigida e independiente de fórmulas de nutrición o preparados infantiles, analizar el abanico nutricional actual en España y evaluar los datos de uso de la herramienta. Métodos: se desarrolló la estructura de una base de datos que unifica los parámetros de todas las fórmulas y se analizó el abanico nutricional español. Posteriormente, se seleccionaron los principales algoritmos de búsqueda dirigida y se codificó la herramienta digital. Se llevó a cabo una intensa difusión y se evaluó el impacto obtenido. Se analizaron el perfil de usuarios y centros registrados y los datos de uso de la herramienta y se evaluó su usabilidad mediante el cuestionario System Usability Scale (SUS). Resultados: se obtuvo una web responsive de acceso gratuito (http://nemecum.com) que permite realizar búsquedas dirigidas en base a unos filtros de búsqueda preestablecidos. La herramienta permitió analizar detalladamente el abanico nutricional en España, observándose la gran variedad de fórmulas disponibles de similares características. La campaña de difusión consiguió incrementar su uso de forma exponencial y cuenta actualmente con 1.370 usuarios y 79 centros registrados. La usabilidad fue valorada como excelente. Conclusión: el desarrollo de NEmecum supone una herramienta valiosa en la búsqueda y consulta de datos de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles.
RESUMO
Outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion pumps is postulated as a very promising solution to treat complicated infections, such as endocarditis or osteomyelitis, that require patients to stay in hospital during extended periods of time, thus reducing their quality of life and increasing the risk of complications. However, stability studies of drugs in elastomeric devices are scarce, which limits their use in OPAT. Therefore, we evaluated the stability of ampicillin in sodium chloride 0.9% at two different concentrations, 50 and 15 mg/mL, in an elastomeric infusion pump when stored in the refrigerator and subsequently in real-life conditions at two different temperatures, 25 and 32 °C, with and without the use of a cooling device. The 15 mg/mL ampicillin is stable for up to 72 h under refrigeration, allowing subsequent dosing at 25 °C for 24 h with and without a cooling device, but at 32 °C its concentration drops below 90% after 8 h. In contrast, 50 mg/mL ampicillin only remains stable for the first 24 h under refrigeration, and subsequent administration at room temperature is not possible, even with the use of a cooling system. Our data support that 15 mg/mL AMP is suitable for use in OPAT if the volume and rate of infusion are tailored to the dosage needs of antimicrobial treatments.
RESUMO
Biological drugs, especially those targeting anti-tumour necrosis factor α (TNFα) molecule, have revolutionized the treatment of patients with non-infectious uveitis (NIU), a sight-threatening condition characterized by ocular inflammation that can lead to severe vision threatening and blindness. Adalimumab (ADA) and infliximab (IFX), the most widely used anti-TNFα drugs, have led to greater clinical benefits, but a significant fraction of patients with NIU do not respond to these drugs. The therapeutic outcome is closely related to systemic drug levels, which are influenced by several factors such as immunogenicity, concomitant treatment with immunomodulators, and genetic factors. Therapeutic drug monitoring (TDM) of drug and anti-drug antibody (ADAbs) levels is emerging as a resource to optimise biologic therapy by personalising treatment to bring and maintain drug concentration within the therapeutic range, especially in those patients where a clinical response is less than expected. Furthermore, some studies have described different genetic polymorphisms that may act as predictors of response to treatment with anti-TNFα agents in immune-mediated diseases and could be useful in personalising biologic treatment selection. This review is a compilation of the published evidence in NIU and in other immune-mediated diseases that support the usefulness of TDM and pharmacogenetics as a tool to guide clinicians' treatment decisions leading to better clinical outcomes. In addition, findings from preclinical and clinical studies, assessing the safety and efficacy of intravitreal administration of anti-TNFα agents in NIU are discussed.
RESUMO
BACKGROUND: Inhaled ethanol in the early stages of SARS-CoV-2 infection may reduce the viral load, decreasing progression and improving prognosis. The ALCOVID-19 trial was designed to study the efficacy and safety of inhaled ethanol in older adults at initial phases of infection. METHODS: Randomized, triple-blind, placebo-controlled phase II clinical trial. Experimental group (n = 38) inhaled 65° ethanol through an oxygen flow, while in the control group (n = 37), water for injection was used. General endpoint was to evaluate disease progression according to the modified World Health Organization (WHO) Clinical Progression Scale. Specific effectiveness endpoints were body temperature, oxygen saturation, viral load assessed by cycle threshold (Ct) on real-time polymerase chain reaction (RT-PCR), analytical biomarkers and use of antibiotics or corticosteroids. Specific safety outcomes were the absence of ethanol in plasma, electrographic, analytical, or respiratory alterations. RESULTS: In the intention-to-treat population, no differences were found regarding disease progression. Mean Ct values increased over time in both groups, being numerically higher in the ethanol group, reaching a value above 33 only in the ethanol group on day 14, a value above which patients are considered non-infective. No differences were found in the other specific effectiveness endpoints. Inhaled ethanol was proven to be safe as no plasma ethanol was detected, and there were no electrocardiographic, analytical, or respiratory alterations. CONCLUSIONS: The efficacy of inhaled ethanol in terms of the progression of SARS-CoV-2 infection was not demonstrated in the present trial. However, it is positioned as a safe treatment for elderly patients with early-stage COVID-19.
RESUMO
BACKGROUND AND AIMS: Submucosal injection agents are widely used solutions in gastric polyp resection techniques. Currently, many different solutions are used in clinical practice, but most are not authorised for this use or are not biopharmaceutical characterised. The objective of this multidisciplinary work is to test the efficacy of a novel thermosensitive hydrogel designed specifically for this indication. METHODS: A mixture design of various components (Pluronic®, hyaluronic acid and sodium alginate) was carried out to select the combination with optimal properties for this use. Three final thermosensitive hydrogels were selected on which biopharmaceutical characterisation was performed and stability and biocompatibility were analysed. Efficacy in maintaining elevation was tested ex vivo on pig mucosa and in vivo in pigs RESULTS: The mixture design allowed selection of the ideal combinations of agents for the characteristics sought. The thermosensitive hydrogels studied showed high values of hardness and viscosity at 37 °C, maintaining good syringeability. One of them demonstrated superiority in maintaining polyp elevation in the ex vivo assay and non-inferiority in the in vivo assay. CONCLUSION: The thermosensitive hydrogel specifically designed for this use is promising both for its biopharmaceutical characteristics and for its demonstrated efficacy. This study lays the foundation for evaluating the hydrogel in humans.
Assuntos
Produtos Biológicos , Hidrogéis , Humanos , Animais , Suínos , Temperatura , Poloxâmero , MucosaRESUMO
Age-related macular degeneration (AMD) is a common ocular disease characterized by degeneration of the central area of the retina in the elderly population. Progression and response to treatment are influenced by genetic and non-genetic factors. Proteomics is a powerful tool to study, at the molecular level, the mechanisms underlying the progression of the disease, to identify new therapeutic targets and to establish biomarkers to monitor progression and treatment effectiveness. In this work, we systematically review the use of proteomics-based approaches for the study of the molecular mechanisms underlying the development of AMD, as well as the progression of the disease and on-treatment patient monitoring. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guidelines were followed. Proteomic approaches have identified key players in the onset of the disease, such as complement components and proteins involved in lipid metabolism and oxidative stress, but also in the progression to advanced stages, including factors related to extracellular matrix integrity and angiogenesis. Although anti-vascular endothelial growth factor (anti-VEGF)-based therapy has been crucial in the treatment of neovascular AMD, it is necessary to deepen our understanding of the underlying disease mechanisms to move forward to next-generation therapies for later-stage forms of this multifactorial disease.
Assuntos
Proteômica , Degeneração Macular Exsudativa , Idoso , Humanos , Inibidores da Angiogênese/uso terapêutico , Acuidade Visual , Degeneração Macular Exsudativa/tratamento farmacológicoRESUMO
OBJECTIVE: To determine and compare the physicochemical and microbiological stability of two 25 IU/mL insulin eye drop formulations made with normal saline and a balanced salt solution, respectively, stored for 120 days under various conditions. METHOD: Eye drops were compounded in triplicate with 100 IU/mL Actrapid® insulin and either normal saline or a balanced salt solution as vehicles, and they were stored alternatively at room temperature (25 °C), in a refrigerator (2-8 °C) or in a freezer (-20 °C) for 120 days. Insulin concentrations were determined by ultra-high resolution liquid chromatography, and osmolality and pH values were measured at days 0, 3, 7, 15, 30, 60, 90 and 120. Likewise, samples were extracted for microbiological studies on days 0, 30, 60, 90 and 120. RESULTS: The formulation made with normal saline maintained insulin concentrations above 90% of the baseline level after 120 days across all temperature conditions. In the case of the balanced salt solution- based eye drops, insulin concentration when stored at room temperature or in the freezer remained stable after 120 days, although insulin concentration when stored in the refrigerator fell below 90% on day 90 of the study. Osmolality and pH values remained constant in both formulations and across all storage conditions. No microbiological growth was observed in any of the samples. CONCLUSIONS: 25 IU/mL insulin eye drops made with normal saline remain stable for 120 days whether they are stored at room temperature, in a refrigerator or in a freezer, provided that they are protected from light. When made with a balanced salt solution, they remain stable for 120 days at room temperature and in a freezer, their shelf life being reduced to 90 days in the case of storage in a refrigerator.
OBJETIVO: Determinar y comparar la estabilidad físico-química y microbiológica de dos colirios de insulina 25 UI/ml elaborados con suero fisiológico o balanced salt solution bajo diferentes condiciones de conservación durante 120 días.Método: Los colirios se elaboraron por triplicado con insulina Actrapid® 100 Ul/ml y balanced salt solution o suero fisiológico como vehículo, y fueron conservados a temperatura ambiente (25 °C), en nevera (2-8 °C) o congelador (20 °C) durante 120 días. Se determinó la concentración de insulina mediante cromatografía liquida de ultra alta resolución, la osmolalidad y el pH a días 0, 3, 7, 15, 30, 60, 90 y 120. Asimismo, se extrajeron muestras para estudios microbiológicos en los días 0, 15, 30, 60, 90 y 120. RESULTADOS: La formulación elaborada con suero fisiológico mantuvo la concentración de insulina por encima del 90% con respecto a la inicial tras 120 días de estudio en todas las condiciones de temperatura. En el caso del colirio elaborado con balanced salt solution, la concentración se mantuvo estable en ambiente y congelador tras 120 días, aunque en nevera descendió por debajo del 90% a día 90 de estudio. Los valores de osmolalidad y pH se mantuvieron constantes en ambas formulaciones y condiciones de conservación. No se observó crecimiento microbiológico en ninguna de las muestras retiradas. CONCLUSIONES: El colirio de insulina 25 UI/ml elaborado con suero fisiológico es estable 120 días, conservado tanto a temperatura ambiente como en nevera o congelador, protegido de la luz. Con balanced salt solution permanece estable 120 días a temperatura ambiente y congelador, reduciéndose el periodo de validez a 90 días en el caso de la conservación en nevera.
Assuntos
Úlcera da Córnea , Humanos , Soluções Oftálmicas/uso terapêutico , Estabilidade de Medicamentos , Insulina/uso terapêutico , Solução Salina , Temperatura , Armazenamento de MedicamentosRESUMO
Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in different tissues and organs causing, among other symptoms, severe ocular manifestations. Cysteamine eye drops are prepared in hospital pharmacy departments to facilitate access to treatment, for which vehicles that provide adequate biopermanence, as well as adaptable containers that maintain its stability, are required. Difficulties related to cysteamine preparation, as well as its tendency to oxidize to cystamine, show the importance of conducting rigorous galenic characterization studies. This work aims to develop and characterize an ophthalmic compounded formulation of cysteamine prepared with hyaluronic acid and packaged in innovative single-dose systems. For this task, the effect of different storage temperatures and the presence/absence of nitrogen on the physicochemical stability of the formulation and its packaging was studied in a scaled manner, until reaching the optimal storage conditions. The results showed that 0.55% cysteamine, prepared with hyaluronic acid and packaged in single-dose containers, is stable for 30 days when stored at -20 °C. In addition, opening vials every 4 h at room temperature after 30 days of freezing maintains the stability of the cysteamine formulation for up to 16 h. Moreover, ocular biopermanence studies were conducted using molecular imaging, concluding that the biopermanence offered by the vehicle is not affected by the freezing process, where a half-life of 31.11 min for a hyaluronic acid formulation stored for 30 days at -20 °C was obtained, compared with 14.63 min for 0.9% sodium chloride eye drops.
RESUMO
Adalimumab is an anti-TNFα drug approved for uveitis treatment by subcutaneous injection. This administration route exposes patients to systemic adverse effects and makes difficult to obtain therapeutic drug concentrations in the site of action due to the anatomical and physiological barriers of the eye. These inconveniences could be avoided by intravitreal injection. The aim of this study is to evaluate the pharmacokinetic profile and the biodistribution of the intravitreal administration of 89Zr-adalimumab in a uveitis rat model using PET imaging. Adalimumab was radiolabelled to 89Zr with a maximum specific activity of 10 MBq/mg. Four µL containing ≃1.74 MBq of 89Zr-labelled adalimumab were injected into the vitreous. A microPET acquisition was carried out immediately after the injection and at different time points through a 10-day study and blood samples were obtained through the tail vein. Radiolabelling was successfully performed with a radiochemical purity after ultrafiltration of 99.69 %. The antibody ocular pharmacokinetics followed a one-compartment model, showing an intraocular elimination half-life of 15.57 h for healthy rats and 33.64 h for rats with uveitis, implying that 89Zr-adalimumab remains around two times longer in rats with the disease compared to healthy ones. However, blood concentration half-life had similar values in both groups. In conclusion, this study shows for the first time the ocular and blood pharmacokinetic analysis of adalimumab in a uveitis model in rats.
Assuntos
Uveíte , Animais , Ratos , Adalimumab/uso terapêutico , Distribuição Tecidual , Uveíte/diagnóstico por imagem , Uveíte/tratamento farmacológico , Injeções Intravítreas , Tomografia por Emissão de Pósitrons/métodosRESUMO
In the last decades, personalized medicine has been increasing its presence in different fields of medicine, including ophthalmology. A new factor that can help us direct medicine towards the challenge of personalized treatments is the microbiome. The gut microbiome plays an important role in controlling immune response, and dysbiosis has been associated with immune-mediated diseases such as non-infectious uveitis (NIU). In this review, we gather the published evidence, both in the pre-clinical and clinical studies, that support the possible role of intestinal dysbiosis in the pathogenesis of NIU, as well as the modulation of the gut microbiota as a new possible therapeutic target. We describe the different mechanisms that have been proposed to involve dysbiosis in the causality of NIU, as well as the potential pharmacological tools that could be used to modify the microbiome (dietary supplementation, antibiotics, fecal microbiota transplantation, immunomodulators, or biologic drugs) and, consequently, in the control of the NIU. Furthermore, there is increasing scientific evidence suggesting that the treatment with anti-TNF not only restores the composition of the gut microbiota but also that the study of the composition of the gut microbiome will help predict the response of each patient to anti-TNF treatment.
Assuntos
Microbioma Gastrointestinal , Microbiota , Uveíte , Disbiose , Transplante de Microbiota Fecal , Microbioma Gastrointestinal/fisiologia , Humanos , Microbiota/fisiologia , Inibidores do Fator de Necrose Tumoral , Uveíte/terapiaRESUMO
In recent years, many studies on population pharmacokinetics of linezolid have been conducted. This comprehensive review aimed to summarize population pharmacokinetic models of linezolid, by focusing on dosage optimization to maximize the probability of attaining a certain pharmacokinetic-pharmacodynamic parameter in special populations. We searched the PubMed and EMBASE databases for population pharmacokinetic analyses of linezolid using a parametric non-linear mixed-effect approach, including both observational and prospective trials. Of the 32 studies, 26 were performed in adults, four in children, and one in both adults and children. High between-subject variability was determined in the majority of the models, which was in line with the variability of linezolid concentrations previously detected in observational studies. Some studies found that patients with renal impairment, hepatic failure, advanced age, or low body weight had higher exposure and adverse reactions rates. In contrast, lower concentrations and therapeutic failure were associated with obese patients, young patients, and patients who had undergone renal replacement techniques. In critically ill patients, the inter-individual and intra-individual variability was even greater, suggesting that this population is at an even higher risk of underexposure and overexposure. Therapeutic drug monitoring may be warranted in a large proportion of patients given that the Monte Carlo simulations demonstrated that the one-size-fits-all labeled dosing of 600 mg every 12 h could lead to toxicity or therapeutic failure for high values of the minimum inhibitory concentration of the target pathogen. Further research on covariates, including renal function, hepatic function, and drug-drug interactions related to P-glycoprotein could help to explain variability and improve linezolid dosing regimens.
Assuntos
Antibacterianos , Estado Terminal , Adulto , Criança , Estado Terminal/terapia , Humanos , Linezolida , Testes de Sensibilidade Microbiana , Método de Monte Carlo , Estudos ProspectivosRESUMO
BACKGROUND: the present work describes the preparation, characterization and optimization of eight types of PLGA-based nanosystems (nanospheres and nanocapsules) as innovative mucoadhesive drug delivery systems of lactoferrin, in order to achieve a preclinical consistent base as an alternative pharmacological treatment to different ocular syndromes and diseases. METHODS: All different nanoparticles were prepared via two modified nanoprecipitation techniques, using a three-component mixture of drug/polymer/surfactant (Lf/PLGA/Poloxamer), as a way to overcome the inherent limitations of conventional PLGA NPs. These modified polymeric nanocarriers, intended for topical ophthalmic administration, were subjected to in vitro characterization, surface modification and in vitro and in vivo assessments. RESULTS: An appropriate size range, uniform size distribution and negative ζ potential values were obtained for all types of formulations. Lactoferrin could be effectively included into all types of nanoparticles with appropriate encapsulation efficiency and loading capacity values. A greater, extended, and controlled delivery of Lf from the polymeric matrix was observed through the in vitro release studies. No instability or cytotoxicity was proved for all the formulations by means of organotypic models. Additionally, mucoadhesive in vitro and in vivo experiments show a significant increase in the residence time of the nanoparticles in the eye surface. CONCLUSIONS: all types of prepared PLGA nanoparticles might be a potential alternative for the topical ophthalmic administration of lactoferrin.
RESUMO
Nanostructured lipid carriers (NLC) are novel lipidic nanosystems that provide significant improvements in terms of high drug loading capacity and controlled drug release. The purpose of the present work was based on the design, development, and physicochemical characterization of lactoferrin-loaded NLCs as a new therapeutic alternative for the keratoconus treatment. Lactoferrin-loaded NLCs were successfully prepared by a double emulsion/solvent evaporation method. The resultant NLC were assessed in terms of particle size, size distribution, surface charge, morphology, encapsulation efficiency (EE), loading capacity (LC), stability, cytotoxicity, in vitro release, and ocular surface retention. Resulting data showed a size of 119.45 ± 11.44 nm, a 0.151 ± 0.045 PDI value and a surface charge of -17.50 ± 2.53 mV. Besides, high EE and LC values were obtained (up to 75%). The in vitro release study demonstrated a lactoferrin controlled release pattern. NLCs were also stable, non-toxic and show mucoadhesive properties. Thus, a consistent preclinical base was obtained, where NLC may be considered as a potential controlled release novel drug delivery system of lactoferrin for the keratoconus treatment.
Assuntos
Portadores de Fármacos , Nanoestruturas , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Lactoferrina , Lipídeos/química , Nanoestruturas/química , Tamanho da PartículaRESUMO
Biodegradable poly(lactic-co-glycolic acid) microspheres (PLGA MSs) are attractive delivery systems for site-specific maintained release of therapeutic active substances into the intravitreal chamber. The design, development, and characterization of idebenone-loaded PLGA microspheres by means of an oil-in-water emulsion/solvent evaporation method enabled the obtention of appropriate production yield, encapsulation efficiency and loading values. MSs revealed spherical shape, with a size range of 10-25 µm and a smooth and non-porous surface. Fourier-transform infrared spectroscopy (FTIR) spectra demonstrated no chemical interactions between idebenone and polymers. Solid-state nuclear magnetic resonance (NMR), X-ray diffractometry, differential scanning calorimetry (DSC) and thermogravimetry (TGA) analyses indicated that microencapsulation led to drug amorphization. In vitro release profiles were fitted to a biexponential kinetic profile. Idebenone-loaded PLGA MSs showed no cytotoxic effects in an organotypic tissue model. Results suggest that PLGA MSs could be an alternative intraocular system for long-term idebenone administration, showing potential therapeutic advantages as a new therapeutic approach to the Leber's Hereditary Optic Neuropathy (LHON) treatment by intravitreal administration.