miRNA nanoencapsulation to regulate the programming of the blood-brain barrier permeability by hypoxia.

Central nervous system (CNS)-related diseases are difficult to treat as most therapeutic agents they cannot reach the brain tissue, mainly due to the blood-brain barrier (BBB), arguably the tightest barrier between the human body and cerebral parenchyma, which routinely excludes most xenobiotic therapeutics compounds. The BBB is a multicellular complex that structurally forms the neurovascular unit (NVU) and is organized by neuro-endothelial and glial cells. BBB breakdown and dysfunction from the cerebrovascular cells lead to leakages of systemic components from the blood into the CNS, contributing to neurological deficits. Understanding the molecular mechanisms that regulate BBB permeability and disruption is essential for establishing future therapeutic strategies to restore permeability and improve cerebrovascular health. MicroRNAs (miRNAs), a type of small non-coding RNAs, are emerging as an important regulator of BBB integrity by modulating gene expression by targeting mRNA transcripts. miRNAs is implicated in the development and progression of various illnesses. Conversely, nanoparticle carriers offer unprecedented opportunities for cell-specific controlled delivery of miRNAs for therapeutic purposes. In this sense, we present in this graphical review critical evidence in the regulation of cell junction expression mediated by miRNAs induced by hypoxia and for the use of nanoparticles for the delivery of miRNA-based therapeutics in the treatment of BBB permeability.

Formulation of Direct Compression Zidovudine Tablets to Correlate the SeDeM Diagram Expert System and the Rotary Press Simulator Styl'ONE Results.

The SeDeM diagram expert system has been applied to study Zidovudine and some excipients. From the obtained diagrams, a pharmaceutical formula has been designed. SeDeM diagram ascertains the critical parameters that are suitable for a direct compression. The formula is compressed using a rotary tablet press simulator which emulates rotary tablet press' compression profiles. From these compressions, we study the formula behavior under different industrial production conditions but saving a huge amount of material. The study is done at different compression forces and compression speeds and taking into account the influence of the pre-compression force. The differences observed between the compression profiles are hereby described. The results indicate that the formulation is able to be compressed adequately with the emulated compression profiles and no differences are observed between the final products. Therefore, we can assure that the SeDeM diagram expert system is accurate and robust. Moreover, its results are comparable with the compression results in a rotary tablet press, which has never been described in the pharmaceutical literature before. From the obtained results, it is possible to select the best rotary press to scale-up this formulation.

The Administration of Chitosan-Tripolyphosphate-DNA Nanoparticles to Express Exogenous SREBP1a Enhances Conversion of Dietary Carbohydrates into Lipids in the Liver of Sparus aurata.

In addition to being essential for the transcription of genes involved in cellular lipogenesis, increasing evidence associates sterol regulatory element binding proteins (SREBPs) with the transcriptional control of carbohydrate metabolism. The aim of this study was to assess the effect of overexpression SREBP1a, a potent activator of all SREBP-responsive genes, on the intermediary metabolism of Sparus aurata, a glucose-intolerant carnivorous fish. Administration of chitosan-tripolyphosphate nanoparticles complexed with a plasmid driving expression of the N-terminal transactivation domain of SREBP1a significantly increased SREBP1a mRNA and protein in the liver of S. aurata. Overexpression of SREBP1a enhanced the hepatic expression of key genes in glycolysis-gluconeogenesis (glucokinase and 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase), fatty acid synthesis (acetyl-CoA carboxylase 1 and acetyl-CoA carboxylase 2), elongation (elongation of very long chain fatty acids protein 5) and desaturation (fatty acid desaturase 2) as well as reduced nicotinamide adenine dinucleotide phosphate production (glucose-6-phosphate 1-dehydrogenase) and cholesterol synthesis (3-hydroxy-3-methylglutaryl-coenzyme A reductase), leading to increased blood triglycerides and cholesterol levels. Beyond reporting the first study addressing in vivo effects of exogenous SREBP1a in a glucose-intolerant model, our findings support that SREBP1a overexpression caused multigenic effects that favoured hepatic glycolysis and lipogenesis and thus enabled protein sparing by improving dietary carbohydrate conversion into fatty acids and cholesterol.

Administration of chitosan-tripolyphosphate-DNA nanoparticles to knockdown glutamate dehydrogenase expression impairs transdeamination and gluconeogenesis in the liver.

Glutamate dehydrogenase (GDH) plays a major role in amino acid catabolism. To increase the current knowledge of GDH function, we analysed the effect of GDH silencing on liver intermediary metabolism from gilthead sea bream (Sparus aurata). Sequencing of GDH cDNA from S. aurata revealed high homology with its vertebrate orthologues and allowed us to design short hairpin RNAs (shRNAs) to knockdown GDH expression. Following validation of shRNA-dependent downregulation of S. aurata GDH in vitro, chitosan-tripolyphosphate (TPP) nanoparticles complexed with a plasmid encoding a selected shRNA (pCpG-sh2GDH) were produced to address the effect of GDH silencing on S. aurata liver metabolism. Seventy-two hours following intraperitoneal administration of chitosan-TPP-pCpG-sh2GDH, GDH mRNA levels and immunodetectable protein decreased in the liver, leading to reduced GDH activity in both oxidative and reductive reactions to about 53-55 % of control values. GDH silencing decreased glutamate, glutamine and aspartate aminotransferase activity, while increased 2-oxoglutarate content, 2-oxoglutarate dehydrogenase activity and 6-phosphofructo-1-kinase/fructose-1,6-bisphosphatase activity ratio. Our findings show for the first time that GDH silencing reduces transdeamination and gluconeogenesis in the liver, hindering the use of amino acids as gluconeogenic substrates and enabling protein sparing and metabolisation of dietary carbohydrates, which would reduce environmental impact and production costs of aquaculture.

The role of SeDeM for characterizing the active substance and polyvinyilpyrrolidone eliminating metastable forms in an oral lyophilizate-A preformulation study.

A preformulation study of an oral lyophilisate with cetirizine dihydrochloride (CTZ) as active ingredient, mannitol and PVP K30 as bulking agents is presented. CTZ shown a humidity content of 0.150% and a spontaneous hygroscopicity of 0.200% (both determined by SeDeM diagram), demonstrating an adequate stability behavior in solid form. A design of experiments (DoE) performed with both mannitol and PVP K30, followed by a simple factorial design (32) has determined the optimum combination of excipients and CTZ, and showed that a higher proportion of PVP K30 was able to prevent metastable forms generated by mannitol.

Development and validation of a simple high-performance liquid chromatography analytical method for simultaneous determination of phytosterols, cholesterol and squalene in parenteral lipid emulsions.

A simple analytical method for simultaneous determination of phytosterols, cholesterol and squalene in lipid emulsions was developed owing to increased interest in their clinical effects. Method development was based on commonly used stationary (C18 , C8 and phenyl) and mobile phases (mixtures of acetonitrile, methanol and water) under isocratic conditions. Differences in stationary phases resulted in peak overlapping or coelution of different peaks. The best separation of all analyzed compounds was achieved on Zorbax Eclipse XDB C8 (150 × 4.6 mm, 5 µm; Agilent) and ACN-H2 O-MeOH, 80:19.5:0.5 (v/v/v). In order to achieve a shorter time of analysis, the method was further optimized and gradient separation was established. The optimized analytical method was validated and tested for routine use in lipid emulsion analyses.

Improved formulation of cationic solid lipid nanoparticles displays cellular uptake and biological activity of nucleic acids.

Non-viral delivery using cationic solid lipid nanoparticles (SLNs) represents a useful strategy to introduce large DNA and RNA molecules to target cells. A careful selection of components and their amounts is critical to improve transfection efficiency. In this work, a selected and optimized formulation of SLNs was used to efficiently transfect circular DNA and linear RNA molecules into cells. We characterized the main physicochemical characteristics and binding capabilities of these SLNs and show that they deliver DNA and RNA molecules into cells where they display full bioactivity at nontoxic concentrations using fluorescence- and luminescence-based methodologies. Hence, we established a novel and simple SLN formulation as a powerful tool for future therapeutic use.

Chitosan-Mediated shRNA Knockdown of Cytosolic Alanine Aminotransferase Improves Hepatic Carbohydrate Metabolism.

Alanine aminotransferase (ALT) catalyses a transamination reaction that links carbohydrate and amino acid metabolism. In this study, we examined the effect of silencing cytosolic ALT (cALT) expression on the hepatic metabolism in Sparus aurata. A number of siRNA and shRNA designed to down-regulate cALT expression were validated in HEK-293 cells transfected with plasmids expressing S. aurata cALT or mitochondrial ALT (mALT) isoforms: ALT silencing significantly decreased the expression levels of S. aurata mRNA cALT1 to 62% (siRNA) and 48% (shRNA) of the values observed in control cells. The effect of cALT silencing was analysed in the liver of S. aurata 72 h after intraperitoneal injection of chitosan-tripolyphosphate (TPP) nanoparticles complexed with a plasmid encoding a shRNA to down-regulate cALT expression (pCpG-si1sh1). In fish fed diets with different ratio of protein to carbohydrate and treated with chitosan-TPP-pCpG-si1sh1, cALT1 and cALT2 mRNA levels significantly decreased irrespective of the diet. Consistently, ALT activity decreased in liver of treated animals. In the liver of S. aurata treated with chitosan-TPP-pCpG-si1sh1 nanoparticles, down-regulation of cALT expression increased the activity of key enzymes in glycolysis (6-phosphofructo-1-kinase and pyruvate kinase) and protein metabolism (glutamate dehydrogenase). Besides showing for the first time that administration of chitosan-TPP-pCpG-si1sh1 nanoparticles silences hepatic cALT expression in vivo, our data support that down-regulation of cALT could improve the use of dietary carbohydrates to obtain energy and spare protein catabolism.

Determination of stress-induced degradation products of cetirizine dihydrochloride by a stability-indicating RP-HPLC method.

BACKGROUND: A new, simple and accurate stability-indicating reverse phase high performance liquid chromatography method was developed and validated during the early stage of drug development of an oral lyophilizate dosage form of cetirizine dihydrochloride. METHODS: For RP-HPLC analysis it was used an Eclipse XDB C8 column 150 mm × 4.6 mm, 5 µm (Agilent columns, Barcelona, Spain) as the stationary phase with a mobile phase consisted of a mixture of 0.2 M K2HPO4 pH 7.00 and acetonitrile (65:35, v/v) at a flow rate of 1 mL min (-1). Detection was performed at 230 nm using diode array detector. The method was validated in accordance with ICH guidelines with respect to linearity, accuracy, precision, specificity, limit of detection and quantification. RESULTS: The method results in excellent separation between the drug substance and its stress-induced degradation products. The peak purity factor is >950 for the drug substance after all types of stress, which confirms the complete separation of the drug substance peak from its stress induced degradation products. Regression analysis showed r(2) > 0.999 for cetirizine dihydrochloride in the concentration range of 650 µg mL (-1) to 350 µg mL(-1) for drug substance assay and a r(2) > 0.999 in the concentration range of 0.25 µg mL(-1) to 5 µg mL(-1) for degradation products. The method presents a limit of detection of 0.056 µg mL (-1) and a limit of quantification of 0.25 µg mL(-1). The obtained results for precision and accuracy for drug substance and degradation products are within the specifications established for the validation of the method. CONCLUSIONS: The proposed stability-indicating method developed in the early phase of drug development proved to be a simple, sensitive, accurate, precise, reproducible and therefore useful for the following stages of the cetirizine dihydrochloride oral lyophilizate dosage form development.

Chitosan nanoparticles as non-viral gene delivery systems: determination of loading efficiency.

Chitosan has been studied for use in particle delivery systems for therapeutic purposes, since one of its most important applications is as a non-viral vector in gene therapy. Due to its positive charge, it is capable of forming DNA complexes (polyplexes) obtained through several methods and with the property of protecting nucleic acids. Two methods for obtaining the nanoparticles of chitosan-nucleic acids are reported in this study: simple complexation (of depolymerized chitosan or of different chitosan salts with plasmid) and ionic gelation (by adsorption of plasmid in the nanoparticles or by encapsulation of plasmid into nanoparticles). The determination of the loading efficiency of chitosan nanoparticles with the plasmid is carried out by electrophoretic mobility of the samples on agarose gel. Furthermore, the nanoparticles have been characterized according to their morphology, size and surface charge using AFM, TEM, laser diffraction and dynamic light scattering techniques. The polyplexes obtained have been found to be spherical and nanometric in size (between 100-230nm) with a zeta potential between 37 and 48mV. Positive results have been obtained by agarose gel electrophoresis for all studied cases: a concentration of between 20 and 30µg/mL of chitosan salts is required while for the remaining chitosan samples studied, 100% loading efficiency does not occur until a concentration equal to 100µg/mL (regardless of previous depolymerisation and the method performed). Chitosan-plasmid nanocapsules have been obtained at the polymer concentrations worked with (between 0.025 and 0.2%).

A new optimized formulation of cationic solid lipid nanoparticles intended for gene delivery: development, characterization and DNA binding efficiency of TCERG1 expression plasmid.

Solid lipid nanoparticles (SLNs) are being considered as a new approach for therapeutics for many known diseases. In addition to drug delivery, their use as non-viral vectors for gene delivery can be achieved by the inclusion of cationic lipids, which provide a positive surface potential that favours binding to the DNA backbone. This work is based on the idea that the optimization of the components is required as the first step in simplifying the qualitative and quantitative composition of SLNs as much as possible without affecting the essential properties that define SLNs as optimal non-viral vectors for gene delivery. We selected the best lipids and surfactants in terms of particle size and zeta potential and characterized the properties of the resulting nanoparticles using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The SLNs had a particle size of approximately 120 nm and a positive surface charge of 42 mV. In addition, we analysed the main physicochemical characteristics of the bulk components of the nanoparticles using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and mass spectrometry (MS). The suitability of the optimized SLNs for DNA binding was evaluated after the lyophilisation process using a carboxyl-terminal region of the TCERG1 gene, a human factor that has been implicated in several diseases. We show that the SLNs presented high efficiency in the binding of DNA, and importantly, they presented no toxicity when assayed in an in vivo system.

New classification of directly compressible (DC) excipients in function of the SeDeM Diagarm Expert System.

As a methodology for characterizing substances with regard to its viability in direct compression, the SeDeM Diagram Expert System may be considered a new tool in terms of the number of parameters applied and its optimization. The paper is based on the experimental SeDeM characterization study of 51 directly compressible (DC) excipients. After selecting the parameters, and comparing the corresponding results, the choices available within the SeDeM Expert System could be expanded. Through applied variants, the maximum and optimal values of the DC diluent excipient were precisely defined and the mathematical limits of the parameters, functions and parametric indices that define the level of direct compressibility were established. These studies have allowed us to propose a new classification of excipients CD based on its rheological and compressibility capability, resulting in a periodic table of CD excipients. It has been determined that the best excipient for direct compression should have an index of good compression (IGC) of 8.832.

SeDeM expert system a new innovator tool to develop pharmaceutical forms.

CONTEXT: The SeDeM expert system is based on the experimental study and quantitative determination of the characterization parameters of powdered substances, the aim being to determine whether a substance is suitable for producing tablets by means of direct compression (DC) technology, thereby reducing the lead time for pre-formulation studies. Additionally, this expert system also provides formulations with a minimum number of excipients. OBJECTIVE: We used this system to analyze suitable formulas for the production of orodispersible ibuprofen tablets. METHOD: Twenty-one disintegrants and ibuprophen were characterized using SeDeM methodology. RESULTS: The results indicated that production of ibuprofen tablets by DC would require improvements in the dimension and compressibility factors of the active pharmaceutical ingredient. The expert system analysis provided the specific percentage of disintegrant needed to blend with ibuprofen and a standardized formula of lubricants in order to obtain a powder mix that would successfully produce tablets by DC. The eight formulas proposed by SeDeM were produced and tested in the laboratory. CONCLUSION: All eight formulas successfully produced tablets by DC, but only four of them could be considered suitable for use as an orodispersible tablet and accomplishes all the pharmaceutical quality parameters. So, in fact, the use of the SeDeM system reduced the time of medicine's development and therefore the cost of the activity.

DNA delivery via cationic solid lipid nanoparticles (SLNs).

In recent years the use of solid lipid nanoparticles (SLNs) as transport systems for the delivery of drugs and biomolecules has become particularly important. The use of cationic SLNs developed by the technique of microemulsion, which are complexed with DNA in order to study their application as non-viral vectors in gene therapy, is reported. The nanoparticles are characterized by scanning electron microscopy and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Furthermore, the process of lyophilization of the samples and their stability was studied. The nanoparticles obtained presented a particle size of 340 nm with a positive surface charge of 44 mV and the capability of forming lipoplexes with DNA plasmids was stated.

Predicting orally disintegrating tablets formulations of ibuprophen tablets: an application of the new SeDeM-ODT expert system.

This article provides a new innovative tool for pharmaceutical preformulation to predict whether a disintegrant excipient or mixture of powder containing API+excipients is suitable to obtain a bucodispersible tablet by direct compression or not. This innovative tool is the new model SeDeM-ODT that provides the Index of Good Compressibility and Bucodispersibility (IGCB index), which is based on the previous SeDeM expert system that indicates the aptitude of a powder to be compressed. The IGCB index is composed of six main factors (from 15 pharmaceutical raw parameters), which indicate whether a mixture of powder has the aptitude to be compressed by direct compression and at the same time indicates whether these tablets are suitable to be used as a bucodispersible tablet (disintegration time lower than 3 min).

Optimization of parameters of the SeDeM Diagram Expert System: Hausner index (IH) and relative humidity (%RH).

As a methodology for characterizing substances in relation to their viability in direct compression, the SeDeM Diagram Expert System may be considered an open system in terms of the number of parameters applied and the optimization of these parameters. With the experience acquired from applying the SeDeM Diagram, in this study, we propose optimizing the parameters corresponding to the Hausner index (IH) and relative humidity (%HR) in order to simplify the mathematical calculation, so that it provides reliable data that can be extrapolated. The proposed optimization does not involve a conceptual change in the parameters considered nor a significant change in the results obtained compared with the previous calculation methodology initially established for the SeDeM Diagram Expert System, which means that the conclusions obtained by applying this method are equivalent.

Quality and integrity of data in research, development, and innovation: a risk analysis method applied to laboratory notebooks in a university pilot plant.

Risk analysis tools can be applied in the early stages of the research, development, and innovation of pharmaceutical drugs. We used a risk ranking and filtering method to optimize time resources in internal audits of project development documents in order to ensure traceability in a university pilot plant. Data gathered during audits undertaken over a 14 month period were classified according to risk factors at several levels. Consequently, time resources for this type of internal audit can be optimised by focusing on aspects that are objectively determined to be critical to traceability. In addition, quality can be ensured by paying more attention to the most critical aspects, rather than the most commonly observed findings in historical data. LAY ABSTRACT: One of the most important issue for a research, development, and innovation centre is the traceability of both experimental tasks and their documentation. This study describes an analysis of the findings revealed during internal audits carried out over a 14 month period, in order to establish its criticality and to highlight those important aspects to consider in future audits, while saving both personnel and time resources to carry out internal audits on development of projects.

The use of the SeDeM Diagram expert system to determine the suitability of diluents-disintegrants for direct compression and their use in formulation of ODT.

The new SeDeM Diagram expert system was used to analyze the suitability of 43 excipients for direct compression with disintegrant properties from eight chemical families. The SeDeM Diagram expert system is a new method for use in tablet preformulation and formulation studies. It provides the profile of a substance in powder form in terms of its suitability for direct compression. This study, which was based on the current concept of "Quality by Design ICH Q8", evaluated the pharmacotechnical properties of disintegrants in powder form and selected the candidates that were most suitable for direct compression and their use in formulation of orally disintegrating tablets (ODT). To achieve this, each disintegrant and its chemical families were individually analyzed. It was concluded that nine disintegrants had an SeDeM value with the index of good compression (IGC) over 5. Most of these disintegrants were from the microcellulose family. Other disintegrants had indexes that were close to 5. It is assumed that these excipients can be used in direct compression, when they are added to other excipients.

Application of an experimental design for the optimization and validation of a new HPLC method for the determination of vancomycin in an extemporaneous ophthalmic solution.

An experimental design has been used to develop and optimize a new high-performance liquid chromatographic (HPLC) method for the determination of Vancomycin in an extemporaneous ophthalmic solution. After the preliminary studies and literature review, the optimized method was carried out on a second generation of a C18 reverse-phase column (Luna 150 x 4.6 mm i.d., 5 microm particle size) and using methanol as organic phase, a less toxic solvent than acetonitrile, described in the extended literature. The experimental design consisted of a Placket-Burman design where six different variables were studied (flow rate, mL/min; temperature, degrees C; pH mobile phase; % buffer solution; wavelength; and injection volume) to obtain the best suitability parameters (Capacity factor-K', tailing factor, resolution, and theoretical plates). After the optimization of the chromatographic conditions and statistical treatment of the obtained results, the final method uses a mixture of a buffer solution of water-phosphoric acid (85%) (99.83:0.17, v/v) adjusted to pH 3.0 using triethylamine and mixed with methanol (87:13, v/v). The separation is achieved using a flow rate of 1.0 mL/min at 35 degrees C. The UV detector was operated at 280 nm. The validation study carried out, demonstrates the viability of the method, obtaining a good selectivity, linearity, precision, accuracy, and sensitivity.

Application of the SeDeM Diagram and a new mathematical equation in the design of direct compression tablet formulation.

Application of the new SeDeM Method is proposed for the study of the galenic properties of excipients in terms of the applicability of direct-compression technology. Through experimental studies of the parameters of the SeDeM Method and their subsequent mathematical treatment and graphical expression (SeDeM Diagram), six different DC diluents were analysed to determine whether they were suitable for direct compression (DC). Based on the properties of these diluents, a mathematical equation was established to identify the best DC diluent and the optimum amount to be used when defining a suitable formula for direct compression, depending on the SeDeM properties of the active pharmaceutical ingredient (API) to be used. The results obtained confirm that the SeDeM Method is an appropriate system, effective tool for determining a viable formulation for tablets prepared by direct compression, and can thus be used as the basis for the relevant pharmaceutical development.