A Two-Way Proposal for the Determination of Bioequivalence for Narrow Therapeutic Index Drugs in the European Union.

In the European Union, bioequivalence (BE) for narrow therapeutic index (NTI) drugs is currently demonstrated when the 90% confidence interval for the ratio of the population geometric means of the test and reference products for AUC, and in some cases for Cmax, falls within the acceptance range of 90.00% to 111.11%. However, meeting this requirement results in an increased difficulty of demonstrating BE and a need for clinical trials with larger subject sample sizes, especially for medium-to-high variability drugs. To address this challenge, a scaled average BE based on the reference product within-subject variability for narrowing the acceptance range of NTI drugs was recently proposed. However, this approach showed increased type I error (T1E), especially close to the cut-off point between the unscaled and scaled portions of the method. Based on simulations, this limitation can be overcome by predefining the protocol the path to be followed: either the fixed 90.00-111.11% acceptance range approach or the previously proposed scaled average BE approach with a slight adjustment of the one-sided significance level α to 0.042 for a 2 × 3 × 3 partial replicate design and without a lower cut-off point. This results in a mixed approach allowing to reduce the sample size whilst not inflating the T1E.

Comprehensive Genomic Studies on the Cell Blocks of Pancreatic Cancer.

Pancreatic cancer is one of the deadliest malignancies, characterized by late-stage diagnosis and limited treatment options. Comprehensive genomic profiling plays an important role in understanding the molecular mechanisms underlying the disease and identifying potential therapeutic targets. Cell blocks (CBs), derived from EUS-FNA, have become valuable resources for diagnosis and genomic analysis. We examine the molecular profile of pancreatic ductal adenocarcinoma (PDAC) using specimens obtained from CB EUS-FNA, across a large gene panel, within the framework of next-generation sequencing (NGS). Our findings revealed that over half (55%) of PDAC CB cases provided adequate nucleic acid for next-generation sequencing, with tumor cell percentages averaging above 30%. Despite challenges such as low DNA quantification and degraded DNA, sequencing reads showed satisfactory quality control statistics, demonstrating the detection of genomic alterations. Most cases (84.6%) harbored at least one gene variant, including clinically significant gene mutation variants such as KRAS, TP53, and CDKN2A. Even at minimal concentrations, as long as the extracted DNA is of high quality, performing comprehensive molecular profiling on PDAC samples from cell blocks has remained feasible. This strategy has yielded valuable information about the diagnosis, genetic landscape, and potential therapeutic targets, aligning closely with a precision cytopathology approach.

Isolation of bluish anthocyanin-derived pigments obtained from blueberry surplus using centrifugal partition chromatography.

Replacement of synthetic colorants with natural ones is a current marketing trend. Nevertheless, the naturally occurring blue color is rare compared to other colours. In this work, centrifugal partition chromatography (CPC) process was developed as a more efficient and sustainable alternative to reversed phase column chromatography (RP-CC) for the preparative-scale purification of portisins. The strategy began with the extraction of anthocyanins from blueberry surplus and hemi-synthesis of respective portisins. Then, the CPC method development started with the biphasic solvent system selection followed by the optimization of the operating parameters and ended up with a comparison with RP-CC. Aiming at maximizing the portisin content, process throughput, efficiency, and minimizing the environmental risk factor, the effect of sample load (100-500 mg/100 mL of column volume), mobile phase flow rate (10-20 mL/min), and rotation speed (1000-1600 rpm) was evaluated. The two-phase solvent system consisted of tert­butyl­methyl ether, n-butanol, acetonitrile, and water (volume ratio 2:2:1:5) acidified with 0.1 vol.% of HCl was selected. The best conditions were 464 mg of sample/100 mL of column volume, 20 mL/min of mobile phase flow rate, and 1600 rpm of rotation speed at reversed phase mode, allowing the purification of portisins by 5-fold. Compared to the RP-CC, the CPC process efficiency was 2.4 times higher, while the CPC process environmental risk factor was 5.5 times lower. Overall, this study suggests that CPC can be considered an effective, and sustainable alternative process for the preparative isolation of portisins. With this purification approach, the blueberry surplus has been valorized and a naturally derived product has been prepared, allowing its subsequent use as a natural blue colorant.

Hypericum foliosum Quality Botanical and Chemical Markers and In Vitro Antioxidant and Anticancer Activities.

Hypericum foliosum Aiton is an endemic Azorean Hypericum species. Even though the aerial parts of Hypericum foliosum are not described in any official pharmacopoeia, they are utilized in local traditional medicine due to their diuretic, hepatoprotective, and antihypertensive properties. This plant has previously been the subject of phytochemical characterization and has been studied for its antidepressant activity, showing significant results in animal models. The lack of a description of the main characteristics of the aerial parts, which would be necessary to properly identify this medicinal plant species, contributes to the possibility of misidentification events. We performed macroscopic and microscopic analyses that identified specific differential characteristics, such as the absence of dark glands, the dimensions of the secretory pockets in the leaf, and the presence of translucent glands in the powder. To continue our previous work on the biological activity of Hypericum foliosum, ethanol, dichloromethane/ethanol, and water extracts were prepared and studied for their antioxidant and cytotoxic activity. Extracts showed in vitro selective cytotoxic activity in human lung cancer cell line A549, colon cancer cell line HCT 8, and breast cancer cell line MDA-MB-231, with dichloromethane/ethanol showing higher activity against all cell lines (IC50 values of 71.49, 27.31, and 9.51 µg/mL, respectively). All extracts also showed significant antioxidant activity.

(De)Bonding with embryos: The emotional choreographies of Portuguese IVF patients.

In this article we develop the new concept of emotional choreography to describe how patients bond, debond and/or rebond with their embryos created in vitro using assisted reproductive technologies (ART). Using this concept, we explore how the patients' management of their own emotions intertwines with political, scientific, and religious factors. Our analysis relies on and further advances Thompson's concepts of ethical and ontological "choreography". It is through these forms of choreography that complex contemporary biomedical issues with high political, ethical, and scientific stakes are negotiated, and through which different actors, entities, practices, roles, and norms undergo mutual constitution, reinforcement and (re)definition. Our article draws on the analysis of 69 in-depth interviews and the results of an online survey with 85 respondents.

Evaluation of a Proposed Approach for the Determination of the Bioequivalence Acceptance Range for Narrow Therapeutic Index Drugs in the European Union.

Bioequivalence (BE) of products containing narrow therapeutic index (NTI) drugs in the European Union is currently established by demonstrating that the 90% confidence interval for the ratio of the population geometric means of the test compared to the reference product's AUC, and in certain cases Cmax, is included within the tighter acceptance range of 90.00−111.11%. An alternative criterion, consisting of narrowed limits based on the within-subject variability of the reference product, was recently proposed. Its performance for a three-period partial replicate design was tested by simulation in terms of power to show BE, type I error (T1E) and sample size requirements. A new condition, a constraint on the test-to-reference geometric mean ratio (cGMR) to be contained within the range of 90.00−111.11%, was also tested. The probability of showing BE when the products differ more than 10% was increased, but only if the reference product's within-subject variability was moderate-to-high. The inclusion of the additional cGMR limited this. An increase in the T1E (<7%) was observed. The inclusion of the additional cGMR did not change the highest inflation of the T1E. Finally, a significant sample size reduction was observed and the inclusion of the cGMR usually did not increase the required sample size.

Hypericum Genus as a Natural Source for Biologically Active Compounds.

Hypericum L. genus plants are distributed worldwide, with numerous species identified throughout all continents, except Antarctica. These plant species are currently used in various systems of traditional medicine to treat mild depression, wounds and burns, diarrhea, pain, fevers, and their secondary metabolites previously shown, and the in vitro and/or in vivo cytotoxic, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, and hepatoprotective activities, as well as the acetylcholinesterase and monoamine oxidase inhibitory activities. We conducted a systematic bibliographic search according to the Cochrane Collaboration guidelines to answer the question: "What is known about plants of Hypericum genus as a source of natural products with potential clinical biological activity?" We documented 414 different natural products with confirmed in vitro/in vivo biological activities, and 58 different Hypericum plant species as sources for these natural products. Phloroglucinols, acylphloroglucinols, xanthones, and benzophenones were the main chemical classes identified. The selective cytotoxicity against tumor cells, cell protection, anti-inflammatory, antimicrobial, antidepressant, anti-Alzheimer's, and adipogenesis-inhibition biological activities are described. Acylphloroglucinols were the most frequent compounds with anticancer and cell-protection mechanisms. To date, no work has been published with a full descriptive list directly relating secondary metabolites to their species of origin, plant parts used, extraction methodologies, mechanisms of action, and biological activities.

Anacardium occidentale Bark as an Antidiabetic Agent.

Anacardium occidentale L. is used throughout the world to treat type 2 diabetes. In Portugal, a traditional herbal preparation made with stem bark of this species (AoBTHP) has been used for more than 30 years to treat this pathology. The AoBTHP was standardized on total phenolic content, and its hypoglycemic activity was assessed using db/db mice (n = 26) for 92 days. Three doses (40.2, 71.5, and 127.0 mg/kg/day, per os) were tested, and glibenclamide (5 mg/kg/day) was used as positive control. During the study, glycemia was measured under non-fasting or fasting states. In sequence, thin-layer chromatography bioautographic assays were used for the detection of possible alpha- and beta-glucosidase inhibitors. A significant hypoglycemic effect in fasting glycemia in days 31 and 57 was observed with the three tested doses. The 71.5 mg/kg and 127.0 mg/kg AoBTHPs significantly reduced non-fasting glycemia on day 24. The highest dose showed the most significant hypoglycemic effect. Gallic acid was identified as the major alpha- and beta-glucosidase inhibitor. The 127 mg/kg/day AoBTHP dose showed a greater glucose-lowering effect than glibenclamide. For the first time, a standardized AoBTHP was tested using an in vivo diabetes model, and its usage was preclinically validated for type 2 diabetes treatment. The hypoglycemic activity of an AoBTHP can be related to the presence of alpha- and beta-glucosidase inhibitors, such as gallic acid, but other mechanisms can also be involved.

Minimizing the Silver Free Ion Content in Starch Coated Silver Nanoparticle Suspensions with Exchange Cationic Resins.

This work describes the optimization of a methodology for the reduction of silver ions from silver nanoparticle suspensions obtained from low-yield laboratory procedures. The laboratory synthesis of silver nanoparticles following a bottom-up approach starting from silver nitrate, originates silver ions that were not reduced to their fundamental state for nanoparticles creation at the end of the process. However, it is well known that silver ions can easily influence chemical assays due to their chemical reactivity properties and can limit biological assays since they interfere with several biological processes, namely intracellular ones, leading to the death of living cells or organisms. As such, the presence of silver ions is highly undesirable when conducting biological assays to evaluate the influence of silver nanoparticles. We report the development of an easy, low-cost, and rapid methodology that is based on cation exchange resins to minimize the silver ion content in a raw suspension of silver nanoparticles while preserving the integrity of the nanomaterials. This procedure preserves the physical-chemical properties of the nanoparticles, thus allowing the purified nanoparticulate systems to be biologically tested. Different types of cationic resins were tested, and the developed methodology was optimized by changing several parameters. A reduction from 92% to 10% of free silver/total silver ratio was achieved when using the Bio-Rad 50W-X8 100-200 mesh resin and a contact time of 15 min. Filtration by vacuum was used to separate the used resin from the nanoparticles suspension, allowing it to be further reused, as well as the purified AgNPs suspension.

A Proposed Approach for the Determination of the Bioequivalence Acceptance Range for Narrow Therapeutic Index Drugs in the European Union.

The current regulatory criterion for bioequivalence of narrow therapeutic index (NTI) drugs in the European Union requires that the 90% confidence interval for the ratio of the population geometric means of the test product compared with the reference for area under the plasma concentration-time curve (AUC), and in certain cases maximum plasma drug concentration (Cmax ), to be included within the tighter acceptance range of 90.00-111.11%. As a consequence, sponsors need to recruit a higher number of subjects to demonstrate bioequivalence and this may be seen as increasing the burden for the development of generics. This "one-size-fits-all" criterion is particularly questionable when the within-subject variability of the reference product is moderate to high. As an alternative, we propose a further refined statistical approach where the acceptance range is narrowed based on the within-subject variability of the reference product of the NTI drug, similar to the one used for widening the standard 80.00-125.00% acceptance range for highly variable drugs. The 80.00-125.00% acceptance range is narrowed, only if the within-subject variability is lower than 30%, down to the current NTI acceptance range of 90.00-111.11% when the within-subject variability is 13.93% or lower. Examples within the current European Medicines Agency list of NTI drugs show a considerable reduction in required sample size for drugs like tacrolimus and colchicine, where the predicted within-subject variability is 20-30%. In these cases, this approach is less sample size demanding without any expected increase in the therapeutic risks, since patients treated with reference products with moderate to high within-subject variability are frequently exposed to bioavailability differences larger than 10%.

In-vitro metaphors: ART beneficiaries' meaning-making about human embryos in the context of IVF in Portugal.

This article proposes a metaphorical approach to the meaning-making of Portuguese assisted reproductive technology (ART) beneficiaries about human embryos created in vitro, based on the analysis of 30 in-depth interviews. This article draws from an ongoing research project on expert and lay definitions of human embryos developed in vitro, both in ART and scientific research. Four metaphors were identified in patients' utterances about the embryo's status and attributes: embryos are possibilities of success of treatment; utilities that can be the object of ownership and dispositional control; potential offspring with whom there are family and emotional ties; and a counter-gift to science or to other beneficiaries, in response to the generosity of professionals or gamete donors. These rhetorical devices seem to ease the tensions inherent in the technical procedures of medically assisted reproduction. Examining the meaning of attributive metaphors used by patients undergoing in-vitro fertilization about their embryos in vitro is thus essential to understanding their personal experiences, so that healthcare professionals can direct their actions/interventions towards their specific needs and concerns, which are not always spoken.

A Single Dose of Marine Chlorella vulgaris Increases Plasma Concentrations of Lutein, ß-Carotene and Zeaxanthin in Healthy Male Volunteers.

The beneficial health effects of Chlorella vulgaris have been associated with the presence of several nutrients and antioxidants, including carotenoids. However, the in vivo bioavailability of Chlorella is still poorly evaluated. In this work, a human intervention study was conducted in 11 healthy men to evaluate the bioavailability of carotenoids within 3 days after the intake of a single dose (6 g) of dried marine Chlorella vulgaris containing lutein (7.08 mg), ß-carotene (1.88 mg) and zeaxanthin (1.47 mg). Subjects were instructed to follow a low carotenoid diet during the experimental phase, starting 1 week earlier. On the day of the experiment, dried microalgae formulated in vegetarian hard capsules were ingested, and blood samples were collected up to 72 h for the analysis of plasma carotenoids concentration by high-performance liquid chromatography with diode-array detection. For all carotenoids, the estimated AUC and Cmax values were significantly different from zero (p < 0.05), indicating that a single dose of marine Chlorella vulgaris increased plasma concentrations of lutein (Cmin-corrected AUC = 1002 µg·h/L, Cmax = 20.4 µg/L), ß-carotene (AUC = 1302 µg·h/L, Cmax = 34.9 µg/L) and zeaxanthin (AUC = 122.2 µg·h/L, Cmax = 3.4 µg/L). The bioavailability of other compounds, namely, polyunsaturated fatty acids and trace elements, was also assessed post-prandial for the first time, showing that linoleic acid, docosahexaenoic acid and iodine were absorbed after microalgae intake. These findings support the use of Chlorella vulgaris as a source of carotenoids, PUFA and essential trace elements with associated health benefits.

A mathematical modeling strategy to predict the spreading behavior on skin of sustainable alternatives to personal care emollients.

Spreadability is one of the most important physicochemical properties of cosmetic products, according to the consumer. Thus, it is fundamental to develop strategies with the aim to improve the knowledge and predict the behavior of alternatives to synthetic emollients. The main goal of this research article was to correlate different physicochemical attributes, namely spreading value, apparent viscosity, density, saponification value, iodine value, peroxide value, acid value and melting range, with the spreading behavior of sustainable alternatives for petrolatum and dimethicone. The sensitivity and adequacy of each parameter were statistically analyzed, and the models were built by forward selection. The two adjusted and optimized models include viscosity and density as parameters and, in the petrolatum case, the model further includes the melting range, which was also validated as a significant predictor. Furthermore, it was also possible to compare the data obtained with the consumer's perception of the spreading behavior of the studied raw materials. A strong correlation was observed, suggesting that these tools mirror the consumer opinion. The application of these mathematical models is a valuable tool to assist the entire replacement process, which usually is a time-consuming procedure.

Nanoparticle-Based Rifampicin Delivery System Development.

The alkaline milieu of chronic wounds severely impairs the therapeutic effect of antibiotics, such as rifampicin; as such, the development of new drugs, or the smart delivery of existing drugs, is required. Herein, two innovative polyelectrolyte nanoparticles (PENs), composed of an amphiphilic chitosan core and a polycationic shell, were synthesized at alkaline pH, and in vitro performances were assessed by 1H NMR, elemental analysis, FT-IR, XRD, DSC, DLS, SEM, TEM, UV/Vis spectrophotometry, and HPLC. According to the results, the nanostructures exhibited different morphologies but similar physicochemical properties and release profiles. It was also hypothesized that the simultaneous use of the nanosystem and an antioxidant could be therapeutically beneficial. Therefore, the simultaneous effects of ascorbic acid and PENs were evaluated on the release profile and degradation of rifampicin, in which the results confirmed their synergistic protective effect at pH 8.5, as opposed to pH 7.4. Overall, this study highlighted the benefits of nanoparticulate development in the presence of antioxidants, at alkaline pH, as an efficient approach for decreasing rifampicin degradation.

Hospitalidade e integração na arquitetura do comum nas sociabilidades escolares / Hospitalidad e integración en la arquitectura de lo común en las sociabilidades escolares / Hospitalité et intégration dans larchitecture du commun des sociabilites scolaires / Hospitality and integration in the making of the common in school sociability

Resumo O presente artigo parte de dados recolhidos de uma pesquisa centrada nas sociabilidades escolares, pretendendo-se, na esteira de uma sociologia dos envolvimentos e comunalidades, trazer à luz outros ângulos da justiça escolar e do fazer o comum na escola. É, concretamente, mobilizada uma técnica designada por questionário por cenários, em que, a partir de uma narrativa de carácter dilemático, pretende-se aceder aos sentidos morais evidenciados por alunos inquiridos. Analisamos em particular as inquietações em torno do respeito, reconhecimento, hospitalidade e decência trazidas à colação por esses atores nas interações e nos juízos críticos produzidos - juízos esses que transcendem leituras meramente feitas a partir dos dispositivos formais reguladores das condutas no espaço escolar.

Resumen El presente artículo parte de los datos recogidos de una pesquisa centrada en las sociabilidades escolares, pretendiéndose, en la huella de una sociología de las participaciones y comunidades, traer a la luz otros ángulos de la justicia escolar y del quehacer habitual en la escuela. Es, concretamente, movilizada una técnica designada por cuestionario por situaciones, en que, a partir de una narrativa de carácter dilemático, se pretende acceder a los sentidos morales evidenciados por alumnos inquiridos. Analizamos en particular las preocupaciones en torno del respeto, reconocimiento, hospitalidad y decencia planteadas por esos actores en las interacciones y en los juicios críticos producidos - juicios esos que transcienden lecturas meramente hechas a partir de los dispositivos formales reguladores de las conductas en el espacio escolar.

Résumé Cet article part des données d'une recherche axée sur les sociabilités scolaires. Dans le sillage d'une sociologie des engagements et des communalités, il s'agit de mettre en lumière d'autres aspects de la justice scolaire et du faire commun en milieu scolaire. Concrètement, à l'aide d'une technique denommée questionnaire par scénarios, à partir d'un récit à caractère dilemmatique, on vise à accéder aux significations morales mises en évidence par les étudiants interrogés. Nous analysons en particulier les préoccupations relatives au respect, à la reconnaissance, à l'hospitalité et à la décence soulevées par ces acteurs dans leurs interactions et leurs jugements critiques, jugements transcendant les lectures qui sont faites uniquement à partir des dispositifs formels régissant les conduites dans l'espace scolaire.

Abstract This article is based on data collected from a research project centred on school sociability, aiming, through a sociology of engagements and commonalities, to shed light on other angles of school justice and the making of the common in the school territory. Specifically, a technique termed scenario survey is mobilized, in which, based on a dilemmatic narrative, the intention is to access the moral meanings evidenced by the inquired students. We analysed particularly their inquietude around respect, recognition, hospitality and decency brought up by these actors in their interactions and critical judgments - judgments that transcend interpretations merely based on the formal governing devices of actor's conduct in the school space.

Starch-Based Pickering Emulsions as Platforms for Topical Antibiotic Delivery: In Vitro and In Vivo Studies.

The present study investigated a new approach to treat superficial skin infections by topical application of minocycline hydrochloride (MH) formulated in a novel starch-based Pickering emulsion (ASt-emulsions). The emulsions were fully characterized in terms of efficacy, as well as in vitro release and permeation studies. The emulsions provided a prolonged MH release, always above its minimum inhibitory concentration against Staphylococcus aureus, although the drug did not permeate through the entire skin layer. The in vitro antibacterial activity of MHASt-emulsions against S. aureus was confirmed and their therapeutic efficacy was assessed using an in vitro skin-adapted agar diffusion test. In vivo antibacterial activity, evaluated using the tape-stripping infection model in mice, showed the topical administration of MH was effective against superficial infections caused by S. aureus. This study supports the potential of ASt-emulsions as promising platforms for topical antibiotic delivery, contributing to a new perspective on the treatment of superficial bacterial infections.

Polymeric Micellar Formulation Enhances Antimicrobial and Anticancer Properties of Salinomycin.

PURPOSE: Salinomycin (SAL) is a polyether compound that exhibits strong antimicrobial as well as anticancer activity. Nanomedicine has been at the forefront of drug delivery research with the aim of increasing the efficacy, specificity and reduce toxicity of drugs. There is an intersection between infection and cancer, and cancer patients are prone to bacterial infections. In this study, polymeric micelles were prepared using Pluronic® F127 (PM) to encapsulate SAL (PM_SAL) with the view of enhancing antimicrobial and anticancer activity. METHODS: A Quality by Design (QbD) approach was utilized to synthesize PM_SAL, and nanoformulation activity was determined against bacterial (S. aureus, MRSA and E. coli). Effects on cancer cell line A549, i.e. cell viability, prevention of P-gp efflux, vimentin expression, effects on migratory ability of A549 cells. Anticancer activity was determined by ability to eradicate cancer stem-like cells. RESULTS: PM_SAL demonstrated only efficacy against MRSA, being even higher than that obtained with SAL. In A549 cells, a 15-fold increase in P-gp's expression as well as a significant decrease of the cell's migration, was observed. CONCLUSIONS: PM_SAL can interfere with the oncogenic protein VIM, involved in the crucial mechanisms EMT, downregulating its expression. Altogether data obtained indicates that this antibiotic and the developed polymeric micelle system is a very promising inhibitor of tumor cell growth.

Functionalization of PLGA Nanoparticles with 1,3-ß-glucan Enhances the Intracellular Pharmacokinetics of Rifampicin in Macrophages.

PURPOSE: Mycobacterium tuberculosis which causes tuberculosis, is primarily resident within macrophages. 1,3-ß-glucan has been proposed as a ligand to target drug loaded nanoparticles (NPs) to macrophages. In this study we characterized the intracellular pharmacokinetics of the anti-tubercular drug rifampicin delivered by 1,3-ß-glucan functionalized PLGA NPs (Glu-PLGA). We hypothesized that Glu-PLGA NPs would be taken up at a faster rate than PLGA NPs, and consequently deliver higher amounts of rifampicin into the macrophages. METHODS: Carbodiimide chemistry was employed to conjugate 1,3-ß-glucan and rhodamine to PLGA. Rifampicin loaded PLGA and Glu-PLGA NPs as well as rhodamine functionalized PLGA and Glu-PLGA NPs were synthesized using an emulsion solvent evaporation technique. Intracellular pharmacokinetics of rifampicin and NPs were evaluated in THP-1 derived macrophages. A pharmacokinetic model was developed to describe uptake, and modelling was performed using ADAPT 5 software. RESULTS: The NPs increased the rate of uptake of rifampicin by a factor of 17 and 62 in case of PLGA and Glu-PLGA, respectively. Expulsion of NPs from the macrophages was also observed, which was 3 fold greater for Glu-PLGA NPs than for PLGA NPs. However, the ratio of uptake to expulsion was similar for both NPs. After 24 h, the amount of rifampicin delivered by the PLGA and Glu-PLGA NPs was similar. The NPs resulted in at least a 10-fold increase in the uptake of rifampicin. CONCLUSIONS: Functionalization of PLGA NPs with 1,3-ß-glucan resulted in faster uptake of rifampicin into macrophages. These NPs may be useful to achieve rapid intracellular eradication of Mycobacterium tuberculosis.

Evaluation of dissolution profile similarity - Comparison between the f2, the multivariate statistical distance and the f2 bootstrapping methods.

A simulation study is presented, evaluating the performance of the f2, the model-independent multivariate statistical distance and the f2 bootstrap methods in the ability to conclude similarity between two dissolution profiles. Different dissolution profiles, based on the Noyes-Whitney equation and ranging from theoretical f2 values between 100 and 40, were simulated. Variability was introduced in the dissolution model parameters in an increasing order, ranging from a situation complying with the European guidelines requirements for the use of the f2 metric to several situations where the f2 metric could not be used anymore. Results have shown that the f2 is an acceptable metric when used according to the regulatory requirements, but loses its applicability when variability increases. The multivariate statistical distance presented contradictory results in several of the simulation scenarios, which makes it an unreliable metric for dissolution profile comparisons. The bootstrap f2, although conservative in its conclusions is an alternative suitable method. Overall, as variability increases, all of the discussed methods reveal problems that can only be solved by increasing the number of dosage form units used in the comparison, which is usually not practical or feasible. Additionally, experimental corrective measures may be undertaken in order to reduce the overall variability, particularly when it is shown that it is mainly due to the dissolution assessment instead of being intrinsic to the dosage form.

Evading P-glycoprotein mediated-efflux chemoresistance using Solid Lipid Nanoparticles.

Multidrug resistance (MDR), whereby cancer cells become resistant to the cytotoxic effects of various structurally and mechanistically unrelated chemotherapeutic agents, is a major problem in the clinical treatment of cancer. P-glycoprotein (P-gp) is a transmembrane protein responsible for drug efflux, which decreases drug intracellular bioavailability, consequently decreasing their efficacy against cancer. Solid Lipid Nanoparticles (SLNs) have not only the ability to protect the entrapped drug against proteolytic degradation, but also allow a selective intracellular targeting. Hypothetically, the entrapped drug enter the target cells by different uptake mechanisms, "nanocitose", as compared to the free drug and may evade efflux-transporters, like P-gp. The functional role of P-gp in limiting the permeability of the anticancer drug paclitaxel (Ptx) was assessed in MDA-MB-436 cells. The observed increase in the pharmacologic efficacy of drug entrapped in SLN relatively to the free drug indicates that this system is shielding the drug. Therefore, "blinding" the nanoparticle from the efflux transporters. The effect was confirmed by the decrease expression of P-gp with loaded-SLNs and through the impact on cellular MDR1 expression. Besides the ability to prevent MDR events, functionalization of SLN with a specific antibody against membrane receptors (anti-CD44v6) improves the nanoparticle capability to target selectively malignant cells. This results allow to anticipate that poor clinical outcomes related to tumour P-gp overexpression might be overcome in a near future.