Efficacy of the treatment using a microemulsion loaded with epoxy-α-lapachone in combination with meglumine antimoniate against murine infection by Leishmania (Leishmania) amazonensis.

Leishmaniasis is a disease caused by Leishmania spp., affecting millions of people around the world. For decades, its treatment has been based on pentavalent antimonials, which notoriously cause toxic side effects in patients. In this study, epoxy-α-lapachone incorporated into an oil-in-water-type microemulsion (ELAP-ME) and meglumine antimoniate (MA) were assayed in monotherapy and in combination (ELAP-ME/MA) in BALB/c mice infected with Leishmania (Leishmania) amazonensis. In general, there was a reduction in paw lesion size (up to 37% reduction) and decreases of parasite loads in the footpad (∼40%) and lymph nodes (∼31%) of animals treated with ELAP-ME/MA, when compared to the non-treated control groups. Analyses of serum biochemical parameters revealed that the ELAP-ME/MA showed lower renal and hepatic toxicity when compared to MA 2-doses/week monotherapy. These findings indicate that the ELAP-ME/MA combination may be a promising approach for the treatment of cutaneous leishmaniasis.

Advancements in Chitosan-Based Nanoparticles for Pulmonary Drug Delivery.

The evolution of respiratory diseases represents a considerable public health challenge, as they are among the leading causes of death worldwide. In this sense, in addition to the high prevalence of diseases such as asthma, chronic obstructive pulmonary disease, pneumonia, cystic fibrosis, and lung cancer, emerging respiratory diseases, particularly those caused by members of the coronavirus family, have contributed to a significant number of deaths on a global scale over the last two decades. Therefore, several studies have been conducted to optimize the efficacy of treatments against these diseases, focusing on pulmonary drug delivery using nanomedicine. Thus, the development of nanocarriers has emerged as a promising alternative to overcome the limitations of conventional therapy, by increasing drug bioavailability at the target site and reducing unwanted side effects. In this context, nanoparticles composed of chitosan (CS) show advantages over other nanocarriers because chitosan possesses intrinsic biological properties, such as anti-inflammatory, antimicrobial, and mucoadhesive capacity. Moreover, CS nanoparticles have the potential to enhance drug stability, prolong the duration of action, improve drug targeting, control drug release, optimize dissolution of poorly soluble drugs, and increase cell membrane permeability of hydrophobic drugs. These properties could optimize the performance of the drug after its pulmonary administration. Therefore, this review aims to discuss the potential of chitosan nanoparticles for pulmonary drug delivery, highlighting how their biological properties can improve the treatment of pulmonary diseases, including their synergistic action with the encapsulated drug.

Assessing nystatin cream treatment efficacy against Leishmania (L.) amazonensis infection in BALB/c model.

The current scenario for cutaneous leishmaniasis treatment includes the use of first and second-choice drugs, both therapeutic strategies presenting several adverse effects and being related to an increment of treatment-refractory parasite strains. These facts encourage the search for new treatment approaches, including repositioning drugs, such as nystatin. Although in vitro assays show that this polyene macrolide compound has leishmanicidal activity, no in vivo evidence for a similar activity has been shown so far for the commercial nystatin cream formulation. This work assessed the effects of nystatin cream (25,000 IU/g) administered on mice in an amount to completely cover the paw surface of BALB/c mice infected with Leishmania (L.) amazonensis once a day, until a total of up to 20 doses. The data presented herein points to unequivocal evidence that treatment with this formulation causes a statistically significant reduction of swelling/edema in mice paws when compared to animal groups not submitted to this treatment regimen after the fourth week of infection: lesion sizes at the sixth (p = 0.0159), seventh (p = 0.0079) and eighth (p = 0.0079) week. Furthermore, swelling/edema reduction relates to a decrease in parasite load in the footpad (∼48%) and in draining lymph nodes (∼68%) at eight weeks post-infection. This is the first report of the effectiveness of nystatin cream used as a topical treatment in BALB/c model for cutaneous leishmaniasis.

In Vitro Release and In Vivo Pharmacokinetics of Praziquantel Loaded in Different Polymer Particles.

Approximately 1 billion people are affected by neglected diseases around the world. Among these diseases, schistosomiasis constitutes one of the most important public health problems, being caused by Schistosoma mansoni and treated through the oral administration of praziquantel (PZQ). Despite being a common disease in children, the medication is delivered in the form of large, bitter-tasting tablets, which makes it difficult for patients to comply with the treatment. In order to mask the taste of the drug, allow more appropriate doses for children, and enhance the absorption by the body, different polymer matrices based on poly(methyl methacrylate) (PMMA) were developed and used to encapsulate PZQ. Polymer matrices included PMMA nano- and microparticles, PMMA-co-DEAEMA (2-(diethylamino)ethyl methacrylate), and PMMA-co-DMAEMA (2-(dimethylamino)ethyl methacrylate) microparticles. The performances of the drug-loaded particles were characterized in vitro through dissolution tests and in vivo through pharmacokinetic analyses in rats for the first time. The in vitro dissolution studies were carried out in accordance with the Brazilian Pharmacopeia and revealed a good PZQ release profile in an acidic medium for the PMMA-DEAEMA copolymer, reaching values close to 100 % in less than 3 h. The in vivo pharmacokinetic analyses were conducted using free PZQ as the control group that was compared with the investigated matrices. The drug was administered orally at doses of 60 mg/kg, and the PMMA-co-DEAEMA copolymer microparticles were found to be the most efficient release system among the investigated ones, reaching a Cmax value of 1007 ± 83 ng/mL, even higher than that observed for free PZQ, which displayed a Cmax value of 432 ± 98 ng/mL.

Development of a microemulsion loaded with epoxy-α-lapachone against Leishmania (Leishmania) amazonensis murine infection.

Epoxy-α-lapachone (ELAP), an oxirane-functionalized molecule synthesized from naturally occurring lapachol, has shown promising activity against murine infection with Leishmania (Leishmania) amazonensis. Herein, we report the successful development of oil-in-water-type (o/w) microemulsions (ME) loaded with ELAP (ELAP-ME) using Capmul MCM, Labrasol, and PEG 400. Stability studies revealed that ELAP-ME (100 µg/mL of ELAP), which was comprised of globule size smaller than 120.4 ± 7.7 nm, displayed a good stability profile over 73 days. ELAP-ME had an effect in BALB/c mice infected with L. (L.) amazonensis, causing reductions in paw lesions after two weeks of treatment (∼2-fold) when compared to untreated animals. Furthermore, there was also a reduction in the parasite load both in the footpad (60.3%) and in the lymph nodes (31.5%). Based on these findings, ELAP-ME emerges as a promising treatment for tegumentar leishmaniasis.

Could the Lung Be a Gateway for Amphotericin B to Attack the Army of Fungi?

Fungal diseases are a significant cause of morbidity and mortality worldwide, primarily affecting immunocompromised patients. Aspergillus, Pneumocystis, and Cryptococcus are opportunistic fungi and may cause severe lung disease. They can develop mechanisms to evade the host immune system and colonize or cause lung disease. Current fungal infection treatments constitute a few classes of antifungal drugs with significant fungi resistance development. Amphotericin B (AmB) has a broad-spectrum antifungal effect with a low incidence of resistance. However, AmB is a highly lipophilic antifungal with low solubility and permeability and is unstable in light, heat, and oxygen. Due to the difficulty of achieving adequate concentrations of AmB in the lung by intravenous administration and seeking to minimize adverse effects, nebulized AmB has been used. The pulmonary pathway has advantages such as its rapid onset of action, low metabolic activity at the site of action, ability to avoid first-pass hepatic metabolism, lower risk of adverse effects, and thin thickness of the alveolar epithelium. This paper presented different strategies for pulmonary AmB delivery, detailing the potential of nanoformulation and hoping to foster research in the field. Our finds indicate that despite an optimistic scenario for the pulmonary formulation of AmB based on the encouraging results discussed here, there is still no product registration on the FDA nor any clinical trial undergoing ClinicalTrial.gov.

In vitro transdermal drug permeation tests: a regulatory scenario evaluation

SUMMARY Introduction: The Transdermal Drug Delivery Systems (TDDS) could circumvent the inconveniences of oral administration, increasing treatment adhesion. Meanwhile, despite being highly widespread systems, there are discrepancies between the performance and quality control methodologies recommended by the leading regulatory agencies, which is an issue for the pharmaceutical industry. Aim: To identify and to compare the requirements for TDDS regulatory approval by important agencies, focusing on the in vitro release and drug permeation studies, which are crucial tests for the evaluation of safety, efficacy, and performance of these systems. Methods: The documents that regulate the scope of TDDS in FDA, EMA and Anvisa were analyze, as well as the contributions of OECD. In addition, an approaching regarding the pharmacopeial requirements was made regarding USA, Europe, and Brazil. Results and conclusion: Concerning the regulatory approval aspects, the FDA is reviewing its documents because the current guidance is not specific to transdermal systems. On the other hand, the EMA presents a unique guideline that includes specific requirements for TDDS. The USA and the European Pharmacopoeias have specific mentions to performance and quality control of TDDS, while the Brazilian Pharmacopoeia does not mention this dosage form. Recently, Anvisa published a guide, which helps Brazilian manufacturers concerning the tests required for the regulatory approval of a new TDDS. The launch of this standardized national statute associated with the use of a validated in vitro release and permeation tests represents a remarkable breakthrough regarding TDDS.

Introducción: los sistemas de administración de fármacos transdérmicos (TDDS) podrían sortear los inconvenientes de la administración por vía oral, aumentando la adherencia al tratamiento. Mientras tanto, a pesar de ser sistemas muy extendidos, existen discrepancias entre las metodologías de desempeño y control de calidad recomendadas por las principales agencias reguladoras, lo cual es un problema para la industria farmacéutica. Objetivo: identificar y comparar los requisitos para la aprobación regulatoria de TDDS por parte de las principales agencias reguladoras, enfocándose en los estudios de liberación in vitro y premiación de fármacos. Métodos: se analizaron los documentos que regulan el alcance de la TDDS en la FDA, EMA y Anvisa, así como los aportes de la OCDE. Además, se realizó un planteamiento sobre los requisitos de las farmacopeas de los Estados Unidos, Europa y Brasil. Resultados y conclusión: la FDA está revisando los aspectos de aprobación regulatoria porque la guía actual no es específica para los sistemas transdérmicos. Por otro lado, la EMA presenta una guía única que incluye requisitos específicos para TDDS. Las farmacopeas de los Estados Unidos e Europa tienen menciones específicas al rendimiento y control de calidad de TDDS, mientras que la Farmacopea brasileña no menciona esta forma de dosificación. Recientemente, Anvisa publicó una guía que ayuda a los fabricantes brasileños en cuanto a las pruebas requeridas para la aprobación regulatoria de un nuevo TDDS. El lanzamiento de este estatuto nacional estandarizado asociado con el uso de pruebas validadas de liberación y premiación in vitro representa un avance notable con respecto a TDDS.

Introdução: os sistemas de liberação transdérmica (SLT) são capazes de contornar as desvantagens da administração oral de medicamentos, aumentando a adesão ao tratamento. Entretanto, apesar de serem sistemas difundidos, existem discrepâncias entre as metodologias de desempenho e controle de qualidade recomendadas pelas agências regulatórias, dificultando o desenvolvimento destes pela indústria farmacêutica. Objetivo: identificar e comparar os requisitos para aprovação regulatória de SLT por importantes agências regulatórias, com foco nos estudos de liberação e permeação de fármacos in vitro, testes fundamentais para avaliação da segurança, eficácia e desempenho desses sistemas. Métodos: foram analisados os documentos que regulam o escopo dos SLT publicados pela FDA, EMA e Anvisa e as contribuições da OCDE. Além disso, foi realizada a abordagem sobre os requisitos farmacopeicos nos Estados Unidos, Europa e Brasil. Resultados e conclusão: FDA está revisando os aspectos de aprovação regulatória, pois os documentos atuais não são específicos para os SLT. Em contraponto, a EMA apresenta uma diretriz única que inclui requisitos específicos para estes sistemas. Em relação às farmacopeias, enquanto EUA e Europa apresentam recomendações específicas para desempenho e controle de qualidade dos SLT, a Farmacopeia brasileira não menciona esta forma farmacêutica. Recentemente, a Anvisa publicou um guia com os testes necessários para o registro destes sistemas. O lançamento de tal publicação, associado a ensaios devidamente validados representam um avanço notável no escopo regulatório dos SLT.

Use of biorelevant dissolution media in dissolution tests as a predictive method of oral bioavailability

Abstract Dissolution is a key step in the uptake of oral drugs. In order to compare the behaviour of the dissolution of two formulations, the dissolution profile test was used. This assay must be discriminative and should mimic in vivo conditions. Many dissolution media described in pharmacopoeias are not predictive of bioavailability. Due to this, biorelevant media are used as an alternative to solve this problem. The objective of this work is to evaluate the relevance of biorelevant dissolution media to predict in vivo drug dissolution. For this, a bibliographic search was carried out in scientific databases. The search was first performed for articles verifying the physicochemical properties of human gastrointestinal fluids. Subsequently, a comparison was made between the properties of gastrointestinal fluids and those of biorelevant and pharmacopoeial media. Finally, the results of bioequivalence studies and dissolution profile tests in biorelevant media described in the literature were compared. The results revealed that there are a few publications that have analysed some physicochemical properties of gastrointestinal fluids. In addition, high variability was observed for some properties. Regarding the comparison of these properties with pharmacopoeial media and biorelevant media, the analysis showed that the biorelevant media are more similar to gastrointestinal fluids than the pharmacopoeial media. Finally, the in vitro dissolution profile results were similar to the results obtained in vivo. Thus, biorelevant media may be useful for analysing dissolution profiles.

Efavirenz dissolution enhancement V - A combined top down/bottom up approach on nanocrystals formulation

Abstract Efavirenz is one of the most commonly used drugs in HIV therapy. However the low water solubility tends to result in low bioavailability. Drug nanocrystals, should enhance the dissolution and consequently bioavailability. The aim of the present study was to obtain EFV nanocrystals prepared by an antisolvent technique and to further observe possible effect, on the resulting material, due to altering crystallization parameters. A solution containing EFV and a suitable solvent was added to an aqueous solution of particle stabilizers, under high shear agitation. Experimental conditions such as solvent/antisolvent ratio; drug load; solvent supersaturation; change of stabilizer; addition of milling step and solvents of different polarities were evaluated. Suspensions were characterized by particle size and zeta potential. After freeze- dried and the resulting powder was characterized by PXRD, infrared spectroscopy and SEM. Also dissolution profiles were obtained. Many alterations were not effective for enhancing EFV dissolution; some changes did not even produced nanosuspensions while other generated a different solid phase from the polymorph of raw material. Nevertheless reducing EFV load produced enhancement on dissolution profile. The most important modification was adding a milling step after precipitation. The resulting suspension was more uniform and the powder presented grater enhancement of dissolution efficacy.

Comparison of in vitro, in vivo, and in silico bioavailability results of different prednisone tablet formulations to assess the feasibility of possible biowaiver / Comparación de los resultados de biodisponibilidad in vitro, in vivo e in silico de diferentes formulaciones de comprimidos de prednisona para evaluar la viabilidad de una posible bioexención

Introducción: Los productos orales sólidos de liberación inmediata que contienen fármacos muy solubles y perme-ables son candidatos para el proceso de bioexención. Este trabajo tiene como objetivo comparar datos in vitro, in silico e in vivo para establecer si las formulaciones de comprimidos orales de prednisona publicadas anteriormente son candidatas a la bioexención. Método: Para lograr este objetivo se realizaron estudios de permeación en células Caco-2. Se aplicó un estudio de bioequivalencia previo entre la formulación de prueba y el medicamento de referencia en una evaluación in silicoutilizando Gastroplus® para evaluar la bioequivalencia de otras dos formulaciones propuestas anteriormente. Resultados: El coeficiente de permeabilidad aparente para prednisona presentó un valor de 3,69 x 10-5 cm/s en 180 minutos. El estudio de bioequivalencia muestra que el producto probado y de referencia era equivalente. Las simulaciones in silicopredijeron con éxito la farmacocinética de las formulaciones probadas y las otras dos, ya que fueron validadas con el estudioin vivo. Ambos exhiben los mismos perfiles de concentración plasmática frente a tiempo. Conclusiones: A través de los resultadosin silico, es posible inferir que las otras dos formulaciones ensayadas pueden ser bioequivalentes respecto al producto de referencia. Este resultado puede ser útil en la solicitud de bio-exenciones. Para reducir los costos y el uso de seres humanos en los estudios de bioequivalencia, este enfoque podría ser una forma esencial de trabajar en la industria farmacéutica. (AU)

Introduction: The immediate-release solid oral products containing very soluble and permeable drugs are candidates for the biowaiver process. This work aims to compare in vitro, in silico, and in vivo data to establish if previously published prednisone oral tablet formulations are biowaiver candidates. Method: To achieve this goal, permeation studies were conducted on Caco-2 cells. A previous bioequivalence study between the test and the reference drug product was applied on an in silico evaluation using Gastroplus® to assess the bioequivalence of two other previously proposed formulations. Results: The apparent permeability coefficient for prednisone presented a value of 3.69 x 10-5 cm/s in 180 minutes. The bioequivalence study shows that the tested and reference product was equivalent. The in silico simulations successfully predicted the pharmacokinetics of the tested and the other two formulations since they were validated with the in vivo study. Both exhibit the same plasma concentration vs. time profiles. Conclusions: Through the in silico results, it is possible to infer that the other two formulations tested may be bioequivalent concerning the reference product. This result may be helpful in biowaiver requesting. Toward to reduce costs and the use of human beings in bioequivalence studies, this approach could be an essential way to work in the pharmaceutical industry. (AU)

In silico bioavailability for BCS class II efavirenz tablets using biorelevant dissolution media for IVIVR and simulation of formulation changes.

OBJECTIVE: This work aims to evaluate the ability of biorelevant dissolution media to simulate the bioavailability of efavirenz tablets, establish an in vitro-in vivo relationship (IVIVR) based on in vivo data using GastroPlus® and simulate formulation changes using DDDPlus™. METHODS: Solubility and drug release profiles were conducted in SLS 0.5% and biorelevant media, such as FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2. The efavirenz physicochemical properties were used to simulate the plasma concentration profile and compare the simulated pharmacokinetic parameters in fasted and fed states. An IVIVR was developed using Loo-Riegelman as the deconvolution method to estimate drug bioavailability. DDDPlus™ was used to perform virtual trials of formulations to evaluate whether formulations changes and the efavirenz particle size could influence the bioavailability. RESULTS: The drug dissolution displayed higher levels in the biorelevant media that simulated gut-fed state (FeSSIF and FeSSIF-V2). The absorption model successfully predicted the efavirenz pharmacokinetics, and FeSSIF-V2 was chosen as the predictive dissolution media, while an IVIVR was established using the Loo-Riegelman deconvolution method. CONCLUSIONS: The present work provides valuable information about efavirenz solubility and kinetics in the gastrointestinal tract, allowing an IVIVR to support future formulation changes. This understanding is essential for rational science-driven formulation development. At least, this study also showed the validity and applicability of in vitro and in silico tools in the regulatory scenario helping on drug development.

The pulmonary route as a way to drug repositioning in COVID-19 therapy.

INTRODUCTION: The outbreak of the disease caused by the new coronavirus (COVID-19) has been affecting society's routine and its patterns of interaction worldwide, in addition to the impact on the global economy. To date, there is still no clinically effective treatment for this comorbidity, and drug repositioning might be a good strategy considering the established clinical safety profile. In this context, since COVID-19 affects the respiratory tract, a promising approach would be the pulmonary drug delivery. OBJECTIVE: Identify repurposing drug candidates for the treatment of COVID-19 based on the data of ongoing clinical trials and in silico studies and also assess their potential to be applied in formulations for pulmonary administration. METHOD: A integrative literature review was conducted between June and July 2020, by extracting the results from Clinical Trials, PubMed, Web of Science and Science Direct databases. RESULTS: By crossing the results obtained from diverse sources, 21 common drugs were found, from which only 4 drugs presented studies of pulmonary release formulations, demonstrating the need for greater investment and incentive in this field. CONCLUSION: Even though the lung is a target that facilitates viral infection and replication, formulations for pulmonary delivery of suitable drugs are still lacking for COVID-19 treatment. However, it is indisputable that the pandemic constitutes a concrete demand, with a profound impact on public health, and that, with the appropriate investments, it will give the pharmaceutical industry an opportunity to reinforce the pulmonary delivery field.

Efavirenz Dissolution Enhancement IV-Antisolvent Nanocrystallization by Sonication, Physical Stability, and Dissolution.

Efavirenz is a fundamental drug in the HIV therapy; however, it has a low bioavailability due to low water solubility. Particle nanonization should enhance its dissolution and therefore its bioavailability. Nanocrystallization is a promising technique for preparing drug nanocrystals. A solution containing efavirenz (EFV) and methanol was added to an aqueous solution of particle stabilizers, under sonication. The adequate polymer stabilizer and its concentration and drug load were evaluated. Particle size and zeta potential of suspensions were measured. Nanosuspensions were freeze-dried and the resulting powder was characterized by some techniques, with special attention to dissolution. Particle size and zeta potential analysis showed that HMPC and PVP were the most suitable polymers. All samples prepared with these stabilizers had nanosized particles and proper zeta potential; however, sedimentation and particle growth were detected with Turbiscan™. Time-related destabilization occurred when the lowest polymer concentration of 20% was used. SEM analysis of the dried powder shows film formation for suspensions with 40% of polymer and particle aggregation in samples with less polymer. Dissolution profiles of samples were higher than EFV raw material, although the lower the polymer concentration, the higher the dissolution.

Prednisone raw material characterization and formulation development

ABSTRACT Solid dosage forms for oral use, particularly tablets, are the most highly used dosage forms in therapy because they are easily administered, have high productivity and relatively low cost and provide a more stable drug to form a semi-solid net. Numerous parameters influence the quality of the final dosage form. In this study, the dissolution profile of 20-mg prednisone tablets bioequivalent to the reference product and three test formulations were evaluated using stability testing. During the study, prednisone tablets and the active pharmaceutical ingredient (API) prednisone from two different manufacturers were characterized with respect to their physical and physicochemical properties. The results showed that the dissolution profiles of the test batches and the reference product did not retain pharmaceutical equivalence throughout all the stability study. Notably, both samples of API prednisone were of the same crystal form, and any phase transition that occurred during the study could not be attributed to dissolution variation during stability.

Evaluation and correlation of the physicochemical properties of carvedilol.

Carvedilol is an antihypertensive drug with non-selective blockade (moderate selectivity for ß1 and ß2 adrenoceptors) and vasodilating properties due to α receptor blockade. Its molecule has one chiral centre; therefore, the drug has two enantiomers. Furthermore, it presents different polymorphs depending on the synthesis route and crystallization procedure. Carvedilol is a weak base that is substantially insoluble in water, acidic solutions, and gastric and intestinal fluids; it is classified as a Class II drug in the Biopharmaceutical Classification System. The solubility of carvedilol varies according to the solvent pH. This study aimed to evaluate and correlate the physicochemical and processability properties of carvedilol. Samples of the active ingredient from three different manufacturers were characterized according to their flowability, particle size and apparent density and using microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, intrinsic dissolution and powder dissolution tests. It was determined that the tested samples presented the same polymorphic form, did not present good flowability, and presented different particle size distributions. The tests to evaluate flowability and compressibility were shown to be discriminative, and slight differences among the samples were noted.

Correlation between microstructure and bioequivalence in anti-HIV drug efavirenz.

Polymorphism and particle size distribution can impact the dissolution behaviour and, as a consequence, bioavailability and bioequivalence of poorly soluble drugs, such as Efavirenz (EFV). Nevertheless, these characteristics do not explain some failures occurring in in vitro assays and in in vivo studies. EFV belongs to Class II and the High Activity Antiretroviral Therapy (HAART) is considered the best choice in the treatment of adults and children. EFV is a drug that needs bioequivalence studies for generic compounds. In this work, six raw materials were analyzed and two of them were utilized with human volunteers (in vivo assays or bioequivalence). All the routine pharmaceutical controls of raw materials were approved; however, the reasons for the failure of the bioequivalence assay could not be explained with current knowledge. The aim of this work was to study microstructure, a solid-state property of current interest in the pharmaceutical area, in order to find an explanation for the dissolution and bioequivalence behaviour. The microstructure of EFV raw materials was studied by Whole Powder Pattern Modelling (WPPM) of X-ray powder diffraction data. Results for different EFV batches showed the biorelevance of the crystalline domain size, and a clear correlation with in vitro (dissolution tests) and in vivo assays (bioequivalence).

Galenic approaches in troubleshooting of glibenclamide tablet adhesion in compression machine punches.

This study aimed to examine the adhesion of glibenclamide 5 mg tablets to the tools of compression machines. This problem is not commonly reported in the literature, since it is considered as tacit knowledge. The starting point was the implementation of three technical alternatives: changing the parameters of compression, evaluating the humidity of the powder blend and the manufacturer of the lubricant magnesium stearate. The adhesion was directly related to the characteristics of magnesium stearate from different manufacturers, and the feasibility of evaluating powder flow characteristics by different techniques that are not routinely followed in various pharmaceutical companies. In vitro dissolution tests showed that the magnesium stearate manufacturer can influence on the dissolution profile of glibenclamide tablets. This study presented various aspects of tablet adhesion to compression machine punches. Troubleshooting approaches can be, most of times, conducted based on previous experience, or an experimental research needs to be implemented in order to have confident results.

Preparação e caracterização no estado sólido de polimorfos do mebendazol / Preparation and solid state characterization of mebendazole polymorphs

O polimorfismo é um fenômeno de grande importância no desenvolvimento de um medicamento. Os polimorfos de um fármaco podem apresentar propriedades físico-químicas diferentes. A pesquisa de polimorfos envolve a realização de experimentos e a caracterização por diferentes técnicas. Neste trabalho, o mebendazol foi escolhido para o estudo de polimorfos. Assim, experimentos de cristalização foram realizados. As amostras foram caracterizadas por diferentes técnicas. Três polimorfos foram obtidos. Os resultados evidenciaram características morfológicas e físico-químicas que permitiram diferenciar as formas cristalinas do mebendazol. Por fim, dez medicamentos comerciais foram avaliados por difração de raios X. Verificou-se a presença, em alguns casos, da forma A, ineficaz, do mebendazol. Este trabalho demonstra que variando-se as condições experimentais é possível obter polimorfos diferentes do mebendazol, inclusive a forma A, não desejada nas formulações. Os métodos analíticos utilizados possibilitam a diferenciação dos polimorfos do mebendazol.

In vitro-in vivo correlation of efavirenz tablets using GastroPlus®.

The aim of the present work was to use GastroPlus™ software for the prediction of pharmacokinetic profiles and in vitro-in vivo correlation (IVIVC) as tools to optimize the development of new generic medications. GastroPlus™ was used to simulate the gastrointestinal compartment and was based on the advanced compartmental absorption and transit model. Powder dissolution and efavirenz tablet dissolution studies were carried out to generate data from which correlation was established. The simulated plasma profile, based on the physicochemical properties of efavirenz, was almost identical to that observed in vivo for biobatches A and B. A level A IVIVC was established for the dissolution method obtained for the generic candidate using the Wagner-Nelson (r (2) = 0.85) and for Loo-Riegelman models (r(2) = 0.92). The percentage of fraction absorbed indicated that 0.5% sodium lauryl sulfate may be considered a biorelevant dissolution medium for efavirenz tablets. The simulation of gastrointestinal bioavailability and IVIVC obtained from immediate-release tablet formulations suggests that GastroPlus™ is a valuable in silico method for IVIVC and for studies directed at developing formulations of class II drugs.