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Considering the importance of the evaluation of quality and performance attributes of herbal medicines, this work evaluated a gynecological gel containing aroeira (Schinus terebinthifolius Raddi), which was previously registered in 2001, and is still marketed in Brazil. Using the updated guides and legislation as a basis, the product was evaluated by checking the pH, spreadability, rheological behavior, in vitro release test, ex vivo permeation and retention study using porcine vaginal mucosa in Franz diffusion cells, and histological evaluation of the porcine vaginal mucosa before and after application of the product. After the permeation study, it was verified that gallic acid (chemical marker quantified) does not cross the mucosa, therefore, it is safe for local use. In addition, the pH of the formulation is within the range considered normal for use in healthy women. Finally, the histological evaluation of the mucosa showed changes compatible with the application of tannins (major compounds of the plant), and without changes indicative of loss of tissue integrity.

Brazil is the world’s largest consumer of pesticides and numerous studies have reported damage to both human health and the environment due to exposure and the toxicity of these agrochemicals. Sugarcane crops present the highest herbicide consumption, leaving the margins of large watersheds. In this study, we have investigated the occurrence of herbicides in the surface waters of three different catchment areas, the rivers: Tracunhaém, Três Bocas and Capibaribe Mirim, all located in Goiana, Pernambuco, in a region outstanding for its intense agroindustrial activity, coastal marine biome and areas of shrimp farming. These rivers supply the domestic, industrial and agricultural consumption of around 26 municipalities of the North region of the Zona da Mata in the state of Pernambuco, and has a population of 465,549. Twelve herbicides were investigated in the waters of the Goiana River using the ultra-efficient liquid chromatography technique coupled with triploquadrupole mass spectrometry (UPLC-MS/MS). The study was conducted from March to August 2019 and detected the presence of residues from the herbicides Ametryn, Atrazine, Diuron and Tebuthiuron during March, April and May, in concentrations ranging from 10 to 150 µg L-1. The results indicate the need to monitor surface water contamination, as current agricultural practices have an unprecedented impact on water quality and consequently on ecosystems and human health.

This survey describes the occurrence of Ethephon (ETH) and Fosetyl in fruits intended for export produced in the Sao Francisco Valley, Brazil. The determination of these compounds was carried out by the QuPPe-method (Quick Polar Pesticides Method), which was optimised and successfully validated according to the SANTE/11813/2017. From January 2016 to December 2018 a total of 1048 samples were analysed for ETH residues. In 547 (53%) of the samples, residues below the EU MRL of 1 mg kg-1 were present. In 17 samples (2%) ETH residues were above 1 mg kg-1. Overall, the mean ETH level decreased after 2016. Analyses of fosetyl showed that (18%) of 109 mango samples were positive for this compound. Phosphonic acid was found in concentrations ranging from 0.12 to 3.2 mg kg-1 and 5% of the measurements were above the EU MRL of 2 mg kg-1. The results emphasise the quality control of fruits produced in this region.

This work attempts to evaluate dermal exposure (DE) of farm workers to dimethoate after 4 h of routine application to a lemon plantation. Dimethoate was measured on the workers' clothes as well as in stratum corneum (SC) and in saliva. In vitro permeation tests (IVPT) were performed through rat, pig and human skin and pig buccal, esophageal and sublingual mucosas. The mean of dimethoate DE was 342.19 ± 487.14 mg/d, the percentage of toxic dose per hour was higher than the other pesticides, and the SC penetration factors ranged between 0.5 and 14.81 and 0.05-53.96 % for back of neck and arms respectively. In the supporting IVPT study, dimethoate absorption through human skin was 14.75 % and the default value in the absence of experimental data for this product is 70%. These results show that in family farming the deficiency of correct clothing during the application of pesticides leaves workers more vulnerable.

Two methods using LC-MS/MS were validated to quantify citalopram (CTP) racemate [(R/S)-CTP] and the enantiomers (R)-CTP and (S)-CTP in human plasma, respectively. Paroxetine hydrochloride was used as the internal standard, and samples were extracted by protein precipitation with acetonitrile. The non-enantioselective method was conducted using a C18 column, and the mobile phase consisted of water for solvent A and acetonitrile for solvent B, both with 0.1% formic acid. For the chiral method, an analytical column Lux Cellulose-1 was used. Mobile phase A was composed of water with 0.025% of formic acid and 0.05% of diethylamine, and mobile phase B consisted of acetonitrile:2-propanol (95:5, v/v). No significant matrix effects were observed at the retention times of analytes and internal standard. The mean recovery was 89%, and the assays were linear in the concentration range of 1-50 and 5-30 ng/mL for the non-enantioselective and enantioselective methods, respectively. The intra- and inter-day precisions of both methods were less than 12.30%, and the accuracies were less than 12.13%. The validated methods were successfully applied to a pharmacokinetic study in which 20-mg CTP tablets were administered to healthy volunteers, and their plasma levels were monitored over time in a bioequivalence study. HIGHLIGHTS: Simple and rapid LC-MS/MS method for the quantification of citalopram and its enantiomers in human plasma. Both methods were demonstrated to be selective, reliable, and sensitive. Both methods have sufficient sensitivity to quantify the steady state through concentrations already reported for citalopram and escitalopram. Validated method presented in this study can be suitably applied to pharmacokinetic studies involving citalopram and escitalopram. Bland-Altman analysis suggested that non-enantioselective and enantioselective methods can be applied in pharmacokinetic studies.

Objetivos: Avaliar o perfil de uso de antimicrobianos na unidade de terapia intensiva (UTI), após implementação do Antimicrobial Stewardship Program (ASP). Métodos: estudo do tipo antes e depois da implementação do programa, realizado de janeiro a dezembro de 2018, envolvendo pacientes com mais de 18 anos, que estiveram internados na UTI, com solicitação de análise microbiológica para apoio diagnóstico de infecção presumida ou confirmada e em uso de antimicrobianos. Foram comparados os resultados dos períodos anterior e posterior à implantação do ASP (1º semestre/2018 versus 2º semestre/2018). Os dados secundários foram obtidos por meio de prontuários e software da unidade de estudo. Foi feita a caracterização da distribuição dos pacientes e monitoradas as variáveis: DDD/1000 pacientes-dia, internados na UTI, número de solicitações de tratamento, média de uso de antimicrobianos por paciente e proporção do consumo de antibióticos, obedecendo à categorização AWaRe. Para análise estatística, foram utilizados os testes t-Student com variâncias desiguais, t-Student com variâncias iguais e teste Mann-Whitney. Resultados: No total, 461 pacientes foram incluídos no estudo. Observou-se que o meropenem foi o antimicrobiano com maior DDD/1000 pacientes-dia em ambos os semestres avaliados (696,67 ± 120,95 versus 481,08 ± 145,23), seguido da vancomicina (316,50 ± 59,89 versus 311,71 ± 89,52). No período pós-intervenção do ASP, houve redução significativa da DDD/1000 pacientes-dia para os antibióticos Meropenem (p = 0,020) e Polimixina B (p = 0,007) e aumento para Piperacilina/Tazobactam. Observou-se um total de 1.605 solicitações de tratamento antimicrobiano em 2018, com redução significativa após intervenção do ASP (147,50 ± 16,63 versus 120,00 ± 18,34, p = 0,022). Considerando a classificação AWaRe, os antibióticos mais utilizados em 2018, em ambos os semestres, corresponderam aos de “Vigilância” (64%), seguidos dos classificados como “Reserva” (21%) e por fim, os de “Acesso” (15%). Conclusões: os resultados apontaram a redução do uso de antimicrobianos, especialmente de antibióticos de amplo espectro, após a intervenção do ASP, o que era esperado, visto que esta é uma ferramenta importante no manejo da terapia antimicrobiana em pacientes acometidos por infecção em unidade de cuidados críticos.

To perform the solid-state characterization and theEFV is an effective anti-HIV drug. Due to the poor aqueous solubility, the rate and extent of EFV absorption deeply depend on its dissolution characteristics.Thermal analyses, x-ray diffraction, and particle size distribution were performed. The saturation solubility and dissolution profiles were assessed in 0.5% (w/v) sodium lauryl sulfate (SLS), fasted-state simulated intestinal fluid (FaSSIF), and fed-state simulated intestinal fluid (FeSSIF) using a flow-through cell. Each batch was orally administered to Wistar rats and the pharmacokinetic parameters were correlated with those obtained fromAll batches of EFV consisted polymorph I. EFV-A presented the lowest particle size distribution [The FaSSIF medium discriminated the dissolution profiles of EFV APIs. Small differences in particle size distribution had a significant impact on the biopharmaceutical parameters of EFV, suggesting that strict control of such parameter is an important aspect during API development and drug formulation.

Terconazole (TCZ) was the first triazole antifungal drug launched in the market and has been used in the treatment of vulvovaginal candidiasis. It is also indicated to treat dermatophytosis and fungal ocular infections. However, some of the degradation products from triazole drugs have been reported to be toxic, justifying the need of further investigations about the stability of TCZ. identification of its degradation products and evaluation of their toxicity considering the new possibilities of therapeutic indications. Therefore, in this work a systematic investigation regarding photostability of TCZ was conducted. The active pharmaceutical ingredient (API) and its methanolic solution (100 µg mL

BACKGROUND: The World Health Organization has declared that a pandemic situation exists in relation to the disease caused by the new coronavirus, COVID-19. So far, the absence of a vaccine against the new coronavirus has led people worldwide to seek various therapeutic alternatives, including use of cholecalciferol. DESIGN AND SETTING: Narrative review developed by a research group at a public university in Recife (PE), Brazil. METHODS: We searched the literature on the use of cholecalciferol for prevention or treatment of COVID-19, using the MEDLINE and LILACS databases, with the keywords “vitamin D”, “cholecalciferol”, “SARS-CoV-2”, “COVID-19” and “coronavirus”, from January 1, 2020, to June 10, 2020. Narrative reviews, cohort studies and ecological studies were selected. RESULTS: We retrieved 32 references, of which 8 were considered eligible for intensive review and critical analysis. These comprised five narrative reviews, two observational studies and one protocol proposal. Most of the studies selected reported positive effects from use of vitamin D for prevention or treatment of COVID-19. However, there was little quantitative data to assess the real impact of using this vitamin as an intervention against this disease. CONCLUSIONS: Current studies on vitamin D used for purposes other than bone health promotion cannot be taken as support to justify its use in a disease as recent as COVID-19. Studies of greater robustness, with higher levels of clinical evidence, need to be conducted. Rational use of this vitamin needs to be ensured, thereby minimizing the impacts on the patient and the public healthcare system.

To perform the solid-state characterization and the in vitro-in vivo correlation (IVIVC) of three batches of efavirenz (EFV) active pharmaceutical ingredients. EFV is an effective anti-HIV drug. Due to the poor aqueous solubility, the rate and extent of EFV absorption deeply depend on its dissolution characteristics. Thermal analyses, x-ray diffraction, and particle size distribution were performed. The saturation solubility and dissolution profiles were assessed in 0.5% (w/v) sodium lauryl sulfate (SLS), fasted-state simulated intestinal fluid (FaSSIF), and fed-state simulated intestinal fluid (FeSSIF) using a flow-through cell. Each batch was orally administered to Wistar rats and the pharmacokinetic parameters were correlated with those obtained from in vitro dissolution. All batches of EFV consisted polymorph I. EFV-A presented the lowest particle size distribution [d(v,0.5) = 197.8 µm; d(v,0.9) = 444.6 µm] followed by EFV-B [d(v,0.5) = 223.9 µm; d(v,0.9) = 481.1 µm], and EFV-C [d(v,0.5) = 240.8 µm; d(v,0.9) = 497.3 µm]. The saturated solubility in FaSSIF was 36% and 40% of that in FeSSIF and SLS, respectively. EFV-A presented the fastest rate and largest extension of dissolution than EFV-B and C (79.15%, 69.93% and 54.22%, respectively, as well as the highest maximum plasma concentration. Levels B, C, and multiple-C of IVIVC models were achieved. The FaSSIF medium discriminated the dissolution profiles of EFV APIs. Small differences in particle size distribution had a significant impact on the biopharmaceutical parameters of EFV, suggesting that strict control of such parameter is an important aspect during API development and drug formulation.

Pain is a phenomenon present in the majority of the population, affecting, among others, the elderly, overweight people, and especially recently operated patients, analgesia being necessary. In the specific case of relief of postoperative pain, different kinds of anesthetics are being used, among them bupivacaine, a widely used drug which promotes long-lasting analgesic effects. However, cardiotoxicity and neurotoxicity are related to its repetitive use. To overcome these shortcomings, Novabupi® (a racemic mixture) was developed and is marketed as an injectable solution. This formulation contains an enantiomeric excess of the levogyre isomer, which has reduced toxicity effects. Seeking to rationalize its use by extending the duration of effect and reducing the number of applications, the objectives of this work were to develop and evaluate liposomes containing Novabupi (LBPV), followed by incorporation into thermogel. Liposomes were prepared using the lipid hydration method, followed by size reduction using sonication, and the developed formulations were characterized by hydrodynamic diameter, polydispersity index (PDI), surface zeta potential, and encapsulation efficiency. The selected optimal liposomal formulation was successfully incorporated into a thermogel without loss of thermoresponsive properties, being suitable for administration as a subcutaneous injection. In the ex vivo permeation studies with fresh rodent skin, the thermogel with liposomes loaded with 0.5% LBPV (T-gel formulation 3) showed higher permeation rates compared to the starting formulation, thermogel with 0.5% LBPV (T-Gel 1), which will probably translate into better therapeutic benefits for treatment of postoperative analgesia, especially with regard to the number of doses applied.

Profissionais de saúde tem prescrito cada vez mais vitamina D, visto que sua deficiência representa um problema de saúde coletiva mundial. Adicionalmente, indivíduos têm utilizado esta substância para outros fins além daqueles ligados ao metabolismo mineral, apesar da escassez de dados científicos sobre seu papel na prevenção de outras doenças. Este trabalho analisou a prescrição, manipulação e uso do colecalciferol em apresentações magistrais e comerciais nacionais. Farmácias magistrais de Recife, PE informaram as formas farmacêuticas manipuladas contendo colecalciferol para administração oral; consultas eletrônicas ao site da Anvisa e ao software INTUITIVE®, utilizado pela Farmácia Escola Carlos Drummond de Andrade (FECDA), permitiram que as apresentações comerciais/manipuladas, no período do estudo, fossem elencadas e analisadas. Foram realizadas consultas a bases de dados visando estabelecer uma análise crítica e atual diante dos achados. Foi verificada uma ampla preocupação no estabelecimento dos níveis sanguíneos adequados desta vitamina na população por parte dos profissionais de saúde habilitados, visto que 29 diferentes especialistas prescreveram colecalciferol manipulado. Também foi constatada uma maior quantidade de dosagens e formas farmacêuticas magistrais quando comparadas com as apresentações comerciais do mercado nacional. No mais, garantir que estas prescrições estejam embasadas nas necessidades de cada paciente, requer exames sanguíneos e utilização de guias reconhecidos, o que, associado ao acompanhamento farmacoterapêutico, poderá contribuir para o sucesso terapêutico.

The adequate management of analgesia, by pharmacological methods or not, is a great challenge. Local anesthetics are used for pain relief, mainly by parenteral, intramuscular, catheter, and other routes of administration. The use of in situ forming systems becomes an alternative for the control of pain. The present research investigates development of thermogels containing poloxamer and levobupivacaine. All formulations were prepared by the cold method; the compatibilities of the excipients were evaluated by DSC, rheology and viscosities, transition temperature, syringeability, release kinetics, and permeation. The compatibility of the tested excipients with the drug was initially observed; all formulations had a viscosity increase at 37°C. Different delivery rates were observed in both the release and permeation studies. The developed systems maintained the in vitro release of the drug for a long period, likely decreasing side effects in vivo and avoiding the need for supplementary analgesia by other routes.

This project was carried out to investigate the feasibility of using microemulsions for transdermal delivery of lapachol. From the screening of surfactants and oils, a range of microemulsions were developed using oleic acid, a mixture of Cremophor EL and Tween 20 and water. The solubility of lapachol was determined in these ingredients and in the formulated microemulsions. The microemulsions were characterised using cross-polarising light microscopy, their electrical conductivity, pH, zeta potential and rheology were analysed, and they were also investigated using small-angle X-ray scattering and differential scanning calorimetry. Ex vivo studies were performed using porcine ear skin and Franz diffusion cells to investigate the permeation and retention of lapachol. Systems containing different concentrations of Cremophor EL (8.4-41.6%), Tween 20 (5.4-41.6%) and oleic acid (12-31.9%) are able to form microemulsions. Lapachol was delivered more effectively through the skin from all of the microemulsions tested than by the control (oleic acid). These studies indicated that microemulsions incorporating lapachol were formed successfully and that these enhanced drug delivery and retention in the skin. Microemulsion systems may, therefore, provide promising vehicles for percutaneous delivery of lapachol.

The aim of this study was to compare the biopharmaceutical characteristics and irritation potentials of microemulsions (MEs) and conventional systems (CSs) containing oil from Syagrus cearensis for topical delivery of Amphotericin B (AmB). Pseudo-ternary phase diagrams were constructed using a water titration method to develop the MEs, and the CSs were prepared according to the classical technique of phase inversion. In the skin permeation and retention study, dermatomed pig skin without stratum corneum was used as an alternative disturbed skin model. The irritation potential was evaluated using three different methods, chorioallantoic membrane assays (HET-CAM and CAM-TBS), and bovine corneal opacity and permeability (BCOP) test. The optimized formulation (ME1) consisting of 0.1% (w/w) Amphotericin B, 9.1% (w/w) catole oil, 81% (w/w) Smix (1:1, Tween 20 and Kolliphor EL) possessed droplet size of 31.02 ± 0.9 nm, zeta potential of −23.4 mV, and viscosity 0.63 ± 0.1 Pa.s. ME1 exhibited greater retention of AmB in to skin layers (84.79 ± 2.08 μg cm−2) than all the others formulations. In general, MEs showed higher drug release and retention than CSs and all of the formulations showed greater retentivity than permeability. Only MEs developed using Labrasol/Plurol Oleique (L/PO) as the surfactant and co-surfactant exhibited a moderate irritation potential; all other MEs and CSs were classified as non-irritants or slight irritants. The results indicate that formulations containing oil from S. cearensis are promising alternatives for the delivery of AmB targeting the treatment of cutaneous leishmaniasis.

Conventional pharmacokinetic profiles of drugs are described mainly by plotting drug plasma concentration versus time. However, topical drugs are designed to target local tissue and, as such, have limited systemic absorption. For these drugs, the pharmacokinetic measurements in the local tissue (skin) are of more importance than systemic measurements. In this context, this study aims to develop and discuss the appropriate bioanalytical methodology by high performance liquid chromatography (HPLC) and application to ex vivo DPK metronidazole (MTZ) study based on the resolution - RE no. 899/2003 and Collegiate Board Resolution – RDC no. 27/2012 guidelines from the National Health Surveillance Agency of Brazil (ANVISA) and the FDA Guidance for Industry Bioanalytical Method Validation (2013). The average of recovery was 98.71% in a linear range from 0.1 to 20 μg/mL. The intraday and interday precision and accuracy were within specified limits to bioanalytical methods. MTZ was not detected in the receptor solution after 6 h, demonstrating that during this time, the drug is not able to cross the skin at a flow, resulting in a concentration higher than 0.1 μg/mL, which is the lower limit of quantification of this method. The amount of MTZ found in the pig SC was 20.91±7.02 µg/cm2 (n=14). Based on these results, it can be concluded that the validation of the drug dosage methodology described here was sensitive, precise and accurate and was successfully applied to analyze ex vivo DPK samples and is an important step for ensuring the reliability of these analyses. Key words: Bioanalytical method, dermatopharmacokinetic (DPK), metronidazole, tape stripping.

This study aims to propose different ex vivo methodologies for pesticide evaluation when in contact with ocular mucosa. The first ex vivo study was performed using vertical Franz cells with fresh and refrigerated excised bovine corneas. The second evaluated the permeation through the cornea by using fresh, refrigerated and damaged whole bovine eyes. Both experiments were evaluated by applying 50 μl (of 5 mg/ml solution) of an emulsifiable pesticide formulation (Dimetoato 500 EC®). In the first study, dimethoate profiles and permeation fluxes showed no statistical differences (p .05) between fresh and refrigerated excised corneas, probably due to the excision procedure generating damage to the cornea by altering stromal structure, irrespective of the refrigeration procedure. In relation to the results obtained for developed ex vivo permeation method in whole eyes, there was a statistical difference (p .05) between experiments performed with fresh eyes and those performed with refrigerated/damaged eyes. Damage generated by both the refrigeration process and exposure to irritant products led to a five-fold reduction in the amount of corneal-permeated pesticide as well as a two-fold increase in retention. Thus, the ex vivo permeation approach with whole eyes seems to be a simple and reproducible method to evaluate pesticides. It is evident that further evaluations need to be performed using other pesticides with distinct physicochemical characteristics.

In order to evaluate dermal absorption during typical working conditions in family farming, the amount of dimethoate on clothing and in the stratum corneum (SC) was measured in three rural workers. This was achieved by using cotton patches on the worker’s clothes and SC quantification by the tape stripping approach. To mimic the above study, an in vitro approach was performed using Franz cells by applying dimethoate (0.4 and 1.8 μg) direct to pig skin or, on a section of cotton before contact with pig skin. The in vivo case results demonstrated the high levels and variability of agrochemicals to which these farmers are subjected, with the total potential dermal absorption between 0.87–2.85 mg/person/h and the estimated SC penetration factor (PF) between 0–54.0 and 0–28.9 % for the back of the neck and the arms respectively. This probably demonstrates the impact of correct protective clothing. For the in vitro study, the amount of pesticide retained in the SC was 52.63 ± 10.73and 135.15 ± 31.8 ng/cm2 after applying 0.4 and 1.8 μg of pesticide directly on SC, and demonstrated close agreement with the in vivo approach. Further studies performed with this and other pesticides with different characteristics will contribute to the understanding of their transport through the skin.

Chagas disease (CD) is recognized as one of the major neglected global tropical diseases. Benznidazole (BNZ) is the drug of choice for the treatment of adults, young infants, and newborns with CD., Chagas disease (CD) is recognized as one of the major neglected global tropical diseases. Benznidazole (BNZ) is the drug of choice for the treatment of adults, young infants, and newborns with CD. However, the pharmacokinetics (PK) of BNZ have been poorly evaluated in all age groups, with consequent gaps in knowledge about PK-pharmacodynamic relationships in CD. The purpose of this study was to develop and validate a bioanalytical method to quantify BNZ levels in small-volume whole-blood samples collected as dried blood spots (DBS). The analysis was performed using high-performance liquid chromatography-positive electrospray tandem mass spectrometry. PK evaluation in healthy male volunteers was conducted to verify the correlation between DBS and plasma BNZ concentrations. The calibration curve was linear from 50 to 20,000 ng · ml−1. Intra- and interday precision and bias values were less than 14.87% (n = 9) and 9.81% (n = 27), respectively. The recovery rates ranged from 94 to 100% with no matrix effect. There was no hematocrit level effect in a range of 20 to 70%. The PK results obtained from DBS and plasma were comparable (r2 = 0.8295) and equivalent to previously published information on BNZ. BNZ in DBS was stable at room temperature for more than one year. This article describes the first microsampling method for measuring BNZ levels in DBS that has the potential to facilitate broad implementation of PK in clinical trials involving adult and pediatric patients in remote areas and helps to address existing knowledge gaps in the treatment of CD.

One major challenge in quantifying drugs in biological matrices is to manage interfering compounds. A technique such liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS) is especially suitable for this application due to its high sensitivity and selectivity in detecting low concentrations of analytes in a complex system. Due to the complexity of LC-MS/MS systems, a number of experimental parameters must be optimized to provide an adequate separation and detection of the analyte. In the present work, a design of experiments approach was developed to optimize an LC-MS/MS-based bioanalytical method to extract olanzapine (OLZ) and quetiapine (QTP) from human plasma. Three steps for the optimization process were conducted: central composite face-centered design to optimize chromatographic parameters (Step 1), ionization in mass spectrometry (Step 2) and a full 32 factorial design to optimize analyte extraction conditions (Step 3). After the optimization process, resolutions and QTP and OLZ retention time (2.3 and 4, respectively) were optimum with pH of 4.7 and 85.5% of acetonitrile for the chromatographic step. Mass spectrometry optimization step provided an increase of (±50%) in the average peak area with high signal-to-noise relationship for the analytes studied. The proposed extraction method was 70% more efficient than the initial method for all drugs analyzed.

This study aimed to examine the influence of the combination of chemical enhancers and a microemulsion on the transdermal permeation of zidovudine (AZT). Ethanol, 1,8-cineole, and geraniol were incorporated in a microemulsion. The droplet size, zeta potential, rheology, and SAXS analysis were performed. The permeation enhancer effect was evaluated using pig ear skin. Snake skin (Boa constrictor) treated with the formulations was also used as a stratum corneum model and studied by attenuated total reflectance-infrared spectroscopy. As a result, it was observed that the incorporation of the chemical enhancers promoted a decrease of the droplet size and some rheological modifications. The 1,8-cineole associated with the microemulsion significantly increased the permeated amount of AZT. Conversely, ethanol significantly increased the quantity of the drug retained in the skin. The probable mechanism for the cineole and ethanol effects was respectively: fluidization and increasing of the diffusion coefficient, and increasing of the partition coefficient. Surprising, geraniol + microemulsion drastically decreased both the permeated and the retained amount of AZT into the skin. Thus, the adequate association of microemulsion and chemical enhancers showed to be a crucial step to enable the topical or transdermal use of drugs.

The topical bioavailabilities of metronidazole from a commercially available ‘reference’ product (Rozex®) and two extemporaneous test formulations were compared. With the reference drug product, a full skin pharmacokinetic profile, in vivo in human volunteers (following a 6-h uptake and clearance over the subsequent 22 h), was obtained using an improved stratum corneum (SC) sampling procedure. Then, a two-time point SC sampling method enabled the bio(in)equivalence of the test formulations to Rozex® to be evaluated. One test formulation was shown to be bioequivalent to Rozex®, both for uptake and clearance, whereas the other (more viscous and less spreadable) formulation was not. The delivery of metronidazole into the underlying viable epidermal tissue from Rozex® and from the equivalent test formulation was 2.5 to 3.5-fold higher than that from the inequivalent extemporaneous vehicle. The results highlight that the quantitative composition of a formulation, as well as its physical properties that influence events that take place at the vehicle-skin interface, can have a dramatic impact on the delivery of drug into the SC and subsequently to the viable skin layers below. The reproducible, sensitive and facile in vivo methodology employed may prove of particular value where regulatory approval of generic formulations lacks objective rigour.

The production of solid drugs generally consists of several steps, which are monitored using quality control assays. In this work, rapid and non-destructive methods, which conform to the principles of the process analytical technology (PAT) framework, were developed for monitoring the production of fixed-dose combination tablets of zidovudine (AZT) and lamivudine (3TC). NIR spectroscopy was employed to determine the content of AZT and 3TC at three different steps of production: in the granulate material, in the core and in the manufactured tablet. NIR chemical images (NIR-CI) were used as a complementary study to evaluate the chemical distribution on the uncoated tablet surfaces, and its internal correlation structures. NIR methods for monitoring the moisture content in the granulate material and the hardness of the tablets before the coating step were also developed. A comparison between two multivariate calibration techniques: PLS and MLR was carried out. The models showed accurate results and prediction errors below those allowed by the regulatory agencies. Through the concentration maps associated with multivariate analysis, the internal chemical structure of API distribution and the excipient increased the understanding of the mixing process, allowing for further improvements.

International audience; Efavirenz (EFV), a first-line anti-HIV drug largely used as part of antiretroviral therapies, is practically insoluble in water and belongs to BCS class II (low solubility/high permeability). The aim of this study was to improve the solubility and dissolution performances of EFV by formulating an amorphous solid dispersion of the drug in polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus (R)) using spray-drying technique. To this purpose, spray-dried dispersions of EFV in Soluplus VR at different mass ratios (1: 1.25, 1: 7, 1: 10) were prepared and characterized using particle size measurements, SEM, XRD, DSC, FTIR and Raman microscopy mapping. Solubility and dissolution were determined in different media. Stability was studied at accelerated conditions (40 degrees C/75% RH) and ambient conditions for 12 months. DSC and XRD analyses confirmed the EFV amorphous state. FTIR spectroscopy analyses revealed possible drug-polymer molecular interaction. Solubility and dissolution rate of EFV was enhanced remarkably in the developed spray-dried solid dispersions, as a function of the polymer concentration. Spray-drying was concluded to be a proper technique to formulate a physically stable dispersion of amorphous EFV in Soluplus VR, when protected from moisture.

The aim of this study was to determine the biopharmaceutical characteristics of oseltamivir carboxylate (OC) after pulmonary delivery. After OC bolus and intratracheal nebulization (NEB) in rats, blood was collected and bronchoalveolar lavages (BALs) were performed. Epithelial lining fluid (ELF) concentrations were estimated from BAL fluid. The area under the curve (AUC) ratio for ELF to plasma was 842 times higher after NEB than after intravenous (i.v.) administration, indicating that OC nebulization offers a biopharmaceutical advantage over i.v. administration.

This study proposed to investigate and to compare colloidal carrier systems containing Zidovudine (3'-azido-3'-deoxythymidine) (AZT) for transdermal administration and optimization of antiretroviral therapy. Microemulsion (ME) and lamellar phase (LP) liquid crystal were obtained and selected from pseudoternary diagrams previously developed. Small-angle X-ray scattering and rheology analysis confirmed the presence of typical ME and liquid crystalline structures with lamellar arrangement, respectively. Both colloidal carrier systems, ME, and LP remained stable, homogeneous, and isotropic after AZT addition. In vitro permeation study (using pig ear skin) showed that the amount of permeated drug was higher for ME compared to the control and LP, obtaining a permeation enhancing effect on the order of approximately 2-fold (p < 0.05). Microscopic examination after in vivo skin irritation studies using mice suggested few histological changes in the skin of animals treated with the ME compared to the control group (hydrogel). Thus, ME proved to be adequate and have promising effects, being able to promote the drug permeation without causing apparent skin irritation. On the order hand, LP functioned as a drug reservoir reducing AZT partitioning into the skin.

The simultaneous determination of two or more active components in pharmaceutical preparations, without previous chemical separation, is a common analytical problem. Published works describe the determination of AZT and 3TC separately, as raw material or in different pharmaceutical preparations. In this work, a method using UV spectroscopy and multivariate calibration is described for the simultaneous measurement of 3TC and AZT in fixed dose combinations. The methodology was validated and applied to determine the AZT+3TC contents in tablets from five different manufacturers, as well as their dissolution profile. The results obtained employing the proposed methodology was similar to methods using first derivative technique and HPLC.

An LC-MS/MS method has been developed for the determination of efavirenz (EFZ) in human plasma using hydrochlorothiazide as internal standard (I.S.). An ESI negative mode with multiple reaction-monitoring was used monitoring the transitions m/z 313.88→69.24 (EFZ) and 296.02→204.76 (I.S.). Samples were extracted using liquid-liquid extraction. The total run time was 2.0 min. The separation was achieved with HPLC-RP using a monolithic column. The assay was linear in the concentration range of 100 - 5000 ng mL-1. The mean recovery was 83%. Intra- and inter-day precision were < 9.5% and < 8.9%, respectively and accuracy was in the range ± 8.33%. The method was successfully applied to a bioequivalence study.

A microemulsion (ME) carrier system containing diclofenac diethylamine (DDA) was developed and physicochemically characterized. In addition, a methodology for analytical determination of DDA by UV-Vis spectrophotometry was validated. The methodology used to produce the ME was simple and reliable, producing a stable ME system with a high DDA entrapment efficiency of 89.6 ± 14.19%. The ME system presents a mean droplet size, conductivity, pH, refractive index and viscosity of around 50 nm, 300 µS cm−1, 7.0, 1.399, and 110 mPa, respectively. Furthermore, the analytical method developed to evaluate the DDA content was validated and used to quantify DDA in the ME formulations.

The goal of this study was to produce and characterize a new microemulsion gel-like carrier system (MEG) by using the pseudo-ternary phase-diagram concept. The diclofenac diethylamine (DDA) was incorporated in the MEG and its in vitro release and permeation profiles were performed using Franz-type diffusion cells. The results revealed that the commercial DDA emulgel provided significantly higher Kp of DDA (2.2-fold) as compared to the MEG. Similar data were obtained in the permeation studies in which DDA Kp 4.7-fold higher. Therefore, MEG presents higher potential as a topical delivery system for DDA when compared to the commercial DDA emulgel.

The analytical method developed to evaluate tamoxifen in dog plasma samples was precise, accurate, robust and linear in the range of 5-200 ng/mL. The limits of detection and quantification were 0.981 ng/mL and 2.97 ng/mL, respectively. Besides, the intra-day precision and accuracy variations were 8.78 and 10.16%, respectively. Tamoxifen concentrations were analyzed by combined reversed phase liquid chromatography and UV detection (lambda=280 nm). The study was conducted using an open randomized 2-period crossover balanced design with a 1-week washout period between the doses. This simple, rapid and selective method is suitable for pharmacokinetic, bioavailability and bioequivalence studies.

We report the development and validation of a new sensitive, accurate and precise HPLC method with ultraviolet detection for the determination of indinavir sulfate (IND) in human plasma and its application to a bioequivalence study of a new generic formulation. The extraction of IND from plasma samples was achieved by using liquid-liquid extraction with a mean recovery of 73.9%. The lower limit of quantification was 0.05 µg/mL. Bioequivalence between the products was determined by calculating 90% confidence intervals (CI) for the ratio of Cmax, AUC0-t and AUC0-inf values for the test and reference products, within the 0.80-1.25 interval proposed by ANVISA and FDA. Therefore the medications are bioequivalent and inter-exchangeable.Foi desenvolvido e validado um novo método, sensível, exato e preciso por Cromatografia a Líquido de Alta Eficiência com detecção em UV para a determinação do sulfato de indinavir (IND) em plasma humano. O fármaco foi extraído do plasma através de extração líquido-líquido obtendo recuperação média de 73.9%, com limite inferior de quantificação de 0.05 µg/mL. O método foi aplicado em estudo de farmacocinética para verificar a bioequivalência entre um novo medicamento genérico e seu produto de referência. A bioequivalência entre os produtos foi determinada calculando-se um intervalo de confiança (IC) de 90% para a razão das médias do produto teste e referência compreendidas entre o intervalo de 0.80-1.25 proposto pela ANVISA e O FDA. Os produtos estudados são bioequivalentes e, portanto, intercambiáveis.