Intraperitoneal Administration of 17-DMAG as an Effective Treatment against Leishmania braziliensis Infection in BALB/c Mice: A Preclinical Study.

BACKGROUND: Leishmaniasis is a significant global public health issue that is caused by parasites from Leishmania genus. With limited treatment options and rising drug resistance, there is a pressing need for new therapeutic approaches. Molecular chaperones, particularly Hsp90, play a crucial role in parasite biology and are emerging as promising targets for drug development. OBJECTIVE: This study evaluates the efficacy of 17-DMAG in treating BALB/c mice from cutaneous leishmaniasis through in vitro and in vivo approaches. MATERIALS AND METHODS: We assessed 17-DMAG's cytotoxic effect on bone marrow-derived macrophages (BMMΦ) and its effects against L. braziliensis promastigotes and intracellular amastigotes. Additionally, we tested the compound's efficacy in BALB/c mice infected with L. braziliensis via intraperitoneal administration to evaluate the reduction in lesion size and the decrease in parasite load in the ears and lymph nodes of infected animals. RESULTS: 17-DMAG showed selective toxicity [selective index = 432) towards Leishmania amastigotes, causing minimal damage to host cells. The treatment significantly reduced lesion sizes in mice and resulted in parasite clearance from ears and lymph nodes. It also diminished inflammatory responses and reduced the release of pro-inflammatory cytokines (IL-6, IFN-γ, TNF) and the regulatory cytokine IL-10, underscoring its dual leishmanicidal and anti-inflammatory properties. CONCLUSIONS: Our findings confirm the potential of 17-DMAG as a viable treatment for cutaneous leishmaniasis and support further research into its mechanisms and potential applications against other infectious diseases.

Early and sustained increase in time in range 1 year after initiation of hybrid close loop therapy via telemedicine in type 1 diabetes patients.

BACKGROUND AND AIMS: Evidence supports the efficacy and safety of the Hybrid Close loop (HCL) system in patients with type 1 diabetes (T1D). However, limited data are available on the long-term outcomes of patients on HCL with telemedicine follow-up. METHODS: A prospective observational cohort study including T1D patients, who were upgrading to HCL system. Virtual training and follow-up were done through telemedicine. CGM data were analyzed to compare the baseline time in range (TIR), time below range (TBR), glycemic variability and auto mode (AM), with measurements performed at 3, 6 and 12 months. RESULTS: 134 patients were included with baseline A1c 7.6% ± 1.1. 40.5% had a severe hypoglycemia event in the last year. Baseline TIR, measured two weeks after starting AM was 78.6 ± 9.94%. No changes were evident at three (Mean difference - 0.15;CI-2.47,2.17;p = 0.96), six (MD-1.09;CI-3.42,1.24;p = 0.12) and 12 months (MD-1.30;CI-3.64,1.04;p = 0.08). No significant changes were found in TBR or glycemic variability throughout the follow-up. Use of AM was 85.6 ± 17.5% and percentage of use of sensor was 88.75 ± 9.5% at 12 months. No severe hypoglycemic (SH) events were reported. CONCLUSIONS: HCL systems allow to improve TIR, TBR and glycemic variability safely, early and sustained up to 1 year of follow-up in patients with T1D and high risk of hypoglycemia followed through telemedicine.

Development of metformin HCl granules using brown flaxseed mucilage as a retardant polymer: effects of polymer and drug ratio

Abstract Flaxseed (Linum usitatissimum L.) is the seed of a multipurpose plant of pharmaceutical interest, as its mucilage can be used as a natural matrix to develop extended-release dosage forms and potentially replace synthetic polymers. In this study, a 3² factorial design with two replicates of the central point was applied to optimize the development of extended-release granules of metformin HCl. The total fiber content of the mucilage as well as the friability and dissolution of the formulations were evaluated. The lyophilized mucilage presented a high total fiber content (42.63%), which suggests a high efficiency extraction process. Higher concentrations of the mucilage and metformin HCl yielded less friable granules. In addition, lower concentrations of metformin HCl and higher concentrations of the mucilage resulted in slower drug release during the dissolution assays. The release kinetics for most formulations were better represented by the Hixson-Crowell model, while formulations containing a higher concentration of the mucilage were represented by the Korsmeyer-Peppas model. Nonetheless, five formulations showed a longer release than the reference HPMC formulation. More desirable results were obtained with a higher concentration of the mucilage (13-18%) and a lower concentration of metformin (40%).

Investigation on formulation parameters of donepezil HCl loaded solid lipid nanoparticles

Abstract Donepezil-HCl is a member of the acetylcholinesterase inhibitors that is indicated for the symptomatic treatment of Alzheimer's disease (AD) and has many side effects. In this study, to reduce the side effects of Donepezil-HCl and increase the penetration of the drug through the blood-brain barrier, we aimed to design a solid lipid nanoparticle (SLN) formulation. The effects of the different formulation parameters, such as homogenization speed, sonication time, lipid and drug concentration, surfactant type and concentration, and volume of the aqueous phase, were assessed for optimization. The particle size and PDI increased with increasing lipid concentration but decreased with increasing amounts of surfactant (Tween 80) and co-surfactant (lecithin). When the homogenization rate and sonication time increased, the particle size decreased and the encapsulation efficiency increased. The optimized formulation exhibited particle size, PDI, encapsulation efficiency, and zeta potential of 87.2±0.11 nm; 0.22±0.02; 93.84±0.01 %; -17.0±0.12 mV respectively. The in vitro release investigation revealed that approximately 70% of Donepezil-HCl was cumulatively released after 24 hours. TEM analysis proved that spherical and smooth particles were obtained and formulations had no toxic effect on cells. The final optimized formulation could be a candidate for Donepezil-HCl application in Alzheimer's treatment with reduced side effects and doses for patients

Treatment of Bovine Leptospirosis with Enrofloxacin HCl 2H2O (Enro-C): A Clinical Trial.

Pharmacokinetics/pharmacodynamics ratios of enrofloxacin HCl-2H2O (enro-C) in cows to treat bovine leptospirosis prompted this clinical trial in the highlands (HL) and the tropics (TL) in Mexico. In the HL, 111 Holstein-Friesian cows were included and 38 F1 Zebu-Holstein/Friesians in the TL. Affected cows were randomly divided into two treatment groups, both in the HL and TL. PCR and MAT tests were performed before and after treatment. Treatments in both groups were administered for 5 d with either IM injections of enro-C or streptomycin/penicillin-G. Reproductive performance data were gathered for 90 d. The cows treated with enro-C became PCR negative: 87.5% and 78.94% on day 5, 92.85% and 94.73% on day 28 (in the HL and TL, respectively). For streptomycin/penicillin-G, the same values were 65.45% and 70.90% on day 5, and 73.68% twice on day 28 in the HL and TL, respectively. In both groups and geographical settings, the MAT titers dropped on day 28 but remained above reference values usually considered negative. The gestation rates were: 86.53% and 79.06% and 88.88% and 87.5% for the HL and TL, either with enro-C or streptomycin/penicillin-G, respectively. This is the first report of successful treatment with a fluoroquinolone derivative in treating bovine leptospirosis with a high bacteriological cure rate.

Edible pectin film added with peptides from jackfruit leaves obtained by high-hydrostatic pressure and pepsin hydrolysis.

Jackfruit (Artocarpus heterophyllus Lam.) is an evergreen tree that produces a high waste of leaves. This study evaluated the obtention of peptides from jackfruit leaves using pancreatin and pepsin, their antifungal activity, and their effect on pectin films. The protein content was 7.64 ± 0.12 g/100 g of jackfruit fresh leaves. Pancreatin produced a higher yield than pepsin in the obtention of peptides (p ≤ 0.05). However, peptides obtained after 2 h by pepsin hydrolysis (Pep-P) had six essential amino acids and inhibited > 99% of mycelial growth and spore germination of Colletotrichum gloeosporioides. Pectin films with Pep-P showed a slight brown color, lower thickness, water vapor permeability, and moisture content, as well as higher thermal stability and better inhibition properties against C. gloeosporioides than pectin films without Pep-P (p ≤ 0.05). Pectin films added with Pep-P from jackfruit leaf could be a green alternative to anthracnose control in tropical fruits.

Virtual training on the hybrid close loop system in people with type 1 diabetes (T1D) during the COVID-19 pandemic.

BACKGROUND AND AIMS: In Colombia, the government established mandatory isolation after the first case of COVID-19 was reported. As a diabetes care center specialized in technology, we developed a virtual training program for patients with type 1 diabetes (T1D) who were upgrading to hybrid closed loop (HCL) system. The aim of this study is to describe the efficacy and safety outcomes of the virtual training program. METHOD: ology: A prospective observational cohort study was performed, including patients with diagnosis of T1D previously treated with multiple doses of insulin (MDI) or sensor augmented pump therapy (SAP) who were updating to HCL system, from March to July 2020. Virtual training and follow-up were done through the Zoom video conferencing application and Medtronic Carelink System version 3.1 software. CGM data were analyzed to compare the time in range (TIR), time below range (TBR) and glycemic variability, during the first two weeks corresponding to manual mode with the final two weeks of follow-up in automatic mode. RESULTS: 91 patients were included. Mean TIR achieved with manual mode was 77.3 ± 11.3, increasing to 81.6% ± 7.6 (p < 0.001) after two weeks of auto mode use. A significant reduction in TBR <70 mg/dL (2,7% ± 2,28 vs 1,83% ± 1,67, p < 0,001) and in glycemic variability (% coefficient of variation 32.4 vs 29.7, p < 0.001) was evident, independently of baseline therapy. CONCLUSION: HCL systems allows T1D patients to improve TIR, TBR and glycemic variability independently of previous treatment. Virtual training can be used during situations that limit the access of patients to follow-up centers.

Contents of tannins of cultivars of sorghum cultivated in Brazil, as determined by four quantification methods.

High tannin content in sorghum grains is an undesirable characteristic for poultry and pig feeding and represents a challenge for breeding programs. On the other hand, moderate content of tannins in sorghum may be beneficial in human diets because they exert anti-cancer, anti-inflammatory and reduced carbohydrate uptake effects, among others. The aim of this study was to compare tannin contents of twenty sorghum cultivars available in Brazil, as well as to compare results obtained with four methods of tannin quantification: butanol/HCl, vanillin/HCl, BSA/FeCl3 and PVPP/Folin-Ciocalteu. The results obtained with butanol/HCl and vanillin/HCl were higher than with BSA/FeCl3 and PVPP/Folin-Ciocalteu. A known amount of purified quebracho tannin was used to test the validation of methods of tannin quantification and vanillin/HCl stood out for its high accuracy degree. The sampling used reveals wide genetic diversity regarding tannin contents. The expectation of predicting tannin contents on basis of grain color seems unfeasible.

Silicon application induces changes C:N:P stoichiometry and enhances stoichiometric homeostasis of sorghum and sunflower plants under salt stress.

Beneficial effects of silicon (Si) on growth have been observed in some plant species, reportedly due to stoichiometric changes of C, N, and P. However, little is known about the effects on the stoichiometric relationships between C, N, and P when silicon is supplied via different modes in sorghum and sunflower plants under salt stress conditions. Therefore, the current study was performed to investigate the impact of differing modes of Si supply on shoot biomass production and C:N:P stoichiometry in sorghum and sunflower plants under salt stress. Two experiments were performed in a glass greenhouse using the strong Si-accumulator plant sorghum, as well as the intermediate type Si-accumulator sunflower, both of which were grown in pots filled with washed sand. Plant species were cultivated for 30 days in the absence or presence of salt stress (0 or 100 mM) and supplemented with one of four Si treatments: control plants (without Si), 28.6 mmol Si L-1 via foliar application, 2.0 mmol Si L-1 via nutrient solution, and combined application of foliar and nutrient solution, each group with five replications. The results revealed that supplied Si modified the C, N, and P concentrations, thereby enhancing the C:N:P stoichiometry and shoot dry matter of sorghum and sunflower plants under salt stress. Both application of Si via nutrient solution, as well as combined application via foliar and nutrient solution, increased the C:N ratio in both plant species under salt stress, but in sorghum plants decreased the C:P and N:P ratios and increased the shoot biomass production by 39%, while in sunflower plants increased the C:P and N:P ratios and increased the shoot biomass production by 24%. Our findings suggest that salt stress alleviation by Si impacts C:N:P stoichiometric relationships in a variable manner depending on the ability of the species to accumulate Si, as well as the route of Si administration.

Logic of Selecting Suitable Dissolution Parameters in New Drug Formulations Based on A BCS Approach.

Since the biopharmaceutical quality of generic drug formulations depends on the quality of the reference products and also information about the in-vitro release performance of drugs under different conditions is scarce in the literature, a dissolution study of four reference tablets was performed. Each drug was representative of one Class of the Biopharmaceutical Classification System. The in-vitro release performance of propranolol-HCl, carbamazepine, ranitidine-HCl, and metronidazole was evaluated using a USP basket and paddle apparatus at different agitation rates (50, 75, and 100 rpm) with two doses of each drug. In all experiments, pharmacopeial dissolution media was used and the samples were taken with automatic equipment at specific times up to 60 min, except for propranolol-HCl, for which the samples were taken up to 30 min. The dissolution profiles were compared by model-independent, model-dependent, and ANOVA-based comparisons. The three methods of data comparison showed that low vs. high doses were significantly different (P < 0.05), which may influence cases in which biowaivers of propranolol-HCl and ranitidine-HCl are requested. Additionally, the results showed that despite different hydrodynamic environments produced by the basket and paddle apparatus, under certain conditions, both types of equipment generated comparable in-vitro results. Variables such as the dose, agitation rate, and type of dissolution apparatus are important factors to consider in designing dissolution tests for drug products. This information can be used to test a new dosage when there is no pharmacopeial method available to perform a dissolution study. Further researches on the in-vitro release performance of reference drug products are required.

In vitro irradiation of doxorubicin with 18F-FDG Cerenkov radiation and its potential application as a theragnostic system.

Doxorubicin (DOX), an effective chemotherapeutic agent, has a wide excitation band centred at 480 nm. Cerenkov radiation (CR) is considered an internal light source in photodynamic therapy (PDT). DOX could be photoactivated by CR and thus, enhancing its cytotoxicity. In this work, 18F-FDG was used to evaluate the effect of Cerenkov radiation on DOX, in comparison to irradiation with a 450-nm laser beam, in terms of ROS production. The production of 1O2 and O2⁎- reactive species during DOX irradiation was detected indirectly by ABMA and DCPIP bleaching, respectively. The cytotoxic effect of the DOX / 18F-FDG CR system was evaluated in the T47D breast cancer cell line. The irradiation of DOX produced 1O2 and O2⁎- species using both 18F-FDG CR and a 450-nm laser beam. The majority reactive species produced in both cases was 1O2; a favourable result, given the greater cytotoxicity of this species. The viability of T47D cells in presence of DOX (5 nM), 18F-FDG (37.5 µCi) and DOX (5 nM)/18F-FDG (37.5 µCi) was (86 ± 9)%, (84 ± 8)% and (64 ± 5)%, respectively; these results suggest a synergistic cytotoxic effect derived from the cytotoxic activity of DOX and its photoactivation by 18F-FDG CR. It is worth noting that the system could be optimized in terms of DOX concentration and 18F-FDG activity for better results. Due to the fact that 18F-FDG is widely used in nuclear imaging, the DOX/18F-FDG system also possesses theragnostic characteristics. Thus, in this work, it is demonstrated that DOX can be used in a dual therapy system based on chemotherapy-PDT when 18F-FDG CR is used as a DOX excitation source.

Impact of Oxycodone HCl Extended-release Formulary Restrictions on Extended-release Opioid Market Share, Healthcare Resource Utilization and Costs in Commercial and Medicare Plans.

Background: Previous research demonstrated that utilization management (UM) such as prior authorization (PA) or non-formulary (NF) restrictions may reduce pharmacy costs when designed and applied appropriately to certain drug classes. However, such access barriers may also have unintended consequences. Few studies systemically analyzed the impact of major UM strategies to extended-release (ER) opioids on different types of health plans. Objective: This study evaluated, from payer perspective, the impact of formulary restrictions (PA, NF, or step therapy [ST]) for branded oxycodone HCl extended release (OER) on market share, and healthcare resource utilization/costs in ER opioids patients for multiple types of health plans in the United States. Methods: This retrospective, longitudinal case-control study analyzed prescription and outpatient medical claims data (2012 to 2015) for adult ER opioid patients from US plans (commercial,/Medicare, national/regional) that instituted OER PA, NF, or ST. Patients from each restricted plan (cases) were matched to patients in an unrestricted plan (controls) on key patient characteristics. ER opioid market share and healthcare resource utilization/costs for both cases and controls were evaluated for the 6-month period before and after the formulary restriction dates. A difference-in-differences (DiD) approach was utilized to evaluate change in the total per patient per month (PPPM) healthcare utilization and costs. Results: The study comprised 1622 (national commercial PA), 2020 (regional commercial PA), 34 703 (national commercial ST), and 4372 (national Medicare NF) cases and equivalent number of controls. OER market share decreased after the formulary restrictions, with the national Medicare NF plan showing the greatest decrease (9.2%). DiD analyses indicated that PPPM office visit change in the PA and NF plans were non-significant (decreased by 0.1 and 0.2, P>0.05), but significant in the ST plan (increased by 0.1, P=0.0001). For most plans, no significant total monthly cost change was observed; PPPM costs decreased by $48.74 and $59.87 in ST and regional PA plans and increased by $37.90 in national NF plans (all P>0.05). Conclusions: This study observed that despite reducing the market share of OER, OER formulary restrictions had negligible impact on overall ER opioid utilization, and did not result in substantial pharmacy/medical cost savings.

Inclusion complex of amiodarone hydrochloride with cyclodextrins: preparation, characterization and dissolution rate evaluation

ABSTRACT This study aimed to improve the water solubility of amiodarone hydrochloride (AMH) via inclusion complexes with β-cyclodextrin, methyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. Inclusion complexes were developed by physical mixture, coevaporation, spray-drying and freeze-drying. Solid state analysis was performed using X-ray powder diffraction, differential scanning calorimetry and scanning electronic microscopy. Thermodynamic studies demonstrate that the inclusion complexes of drug into different cyclodextrins were an exothermic process that occurred spontaneously. Water solubility and drug dissolution rates were significantly increased after the formation of inclusion complexes with the cyclodextrins evaluated in relation to the physical mixture and pure drug. The present study provides useful information for the potential application of complexation with amiodarone HCl. This may be a good strategy for the development of solid pharmaceutical dosage forms.

Formulation, characterization and in vivo evaluation of novel edible dosage form containing nebivolol HCl

ABSTRACT The objective of this investigation was to develop a novel oral edible gel dosage form for nebivolol hydrochloride, with suitable rheological characteristics that can provide a means of administering the drug to dysphagic and geriatric patients. Edible gels were prepared using low acetylated gellan gum and sodium citrate in different concentrations. The effect of concentration of the solution on gelation time, viscosity, and drug release was studied. Optimized formulation had "spoon thick" consistency that is considered suitable for dysphagic patients as suggested by National Dysphagia Diet Task Force. The optimized formulation containing gellan gum (0.4 % w/v) and sodium citrate (0.3 % w/v) showed more than 95% drug release in 20 minutes. This formulation also showed significantly better pharmacokinetic profile when compared to marketed conventional tablets in New Zealand white rabbits (n = 3). Optimized formulation was found stable for 6 months when stored at 25 °C ± 0.2 °C/60 ± 5% RH. From this study, it can be concluded that the novel edible gel dosage form containing nebivolol hydrochloride may prove to be more efficacious in the treatment of hypertension in dysphagic patients.

RESUMO O objetivo deste trabalho foi desenvolver um gel comestível para veiculação de cloridrato de nebivolol, com características reológicas adequadas, que podem fornecer meio de administrar o fármaco em casos de disfagia orofaríngea e pacientes geriátricos. Géis comestíveis foram preparados utilizando goma gelana de baixa acetilação e citrato de sódio, em diferentes concentrações. Estudou-se o efeito da concentração da solução no tempo de gelificação, a viscosidade e a liberação do fármaco. A formulação otimizada apresentava consistência de pudim, o que é considerado adequado para pacientes disfágicos como sugerido pela National Dysphagia Diet Task Force. A formulação otimizada contendo 0,4% (m/v) de goma gelana e 0,3% (m/v) de citrato de sódio mostrou que mais de 95% de fármaco foi liberado em 20 minutos. Esta formulação também mostrou, significativamente, melhor perfil farmacocinético, quando comparado com os comprimidos convencionais comercializados administrados a coelhos brancos neozelandeses (n = 3). A formulação otimizada manteve-se estável durante 6 meses, armazenada a 25 oC ± 0,2 °C/60 ± 5% de UR. A partir deste estudo, conclui-se que a nova forma de gel comestível contendo cloridrato de nebivolol pode ser mais eficaz no tratamento de hipertensão em pacientes portadores de disfagia.

An in vitro-in vivo correlation study of modified release formulations of Venlafaxine. HCl / An in vitro-in vivo correlation study of modified release formulations of Venlafaxine. HCl

A single dose, randomized, complete and four treatment cross over study was conducted in healthy human subjects for IVIVC of venlafaxine.HCl, Plasma concentrations were estimated by a simple, rapid, sensitive and validated LCMS method, Cetirizine was used as the internal standard (IS), The analytes and the IS were extracted from the human plasma by liquid?liquid extraction technique, The reconstituted samples were chromatographed on Kromasil C18 column using an isocratic solvent mixture [acetonitrile?water, 90:10 (v/v)] at a flow rate of 0.5 mL/min, Method validation was performed as per FDA guidelines and the results met the acceptance criteria, USP dissolution apparatus I (Basket) and pH 6.8 at 100 rpm was found to yield acceptable IVIVC for the drug, The developed dissolution method would discriminate bioinequivalent batches, A ?Level A? correlation was observed for the selected formulations at the in vitro dissolution conditions developed, The dissolution method predicted the best absorption rate for the selected modified release formulations, The validity of the correlation was assessed by determining how well the IVIVC model could predict the rate and the extent of absorption as characterized by Cmax and AUC, A percent prediction error of = 10 % for C max and AUC obtained establishes the predictability of the developed IVIVC model, It may, therefore, be concluded that the developed dissolution method can surrogate for human bioequivalence study.

Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo.

In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-ß superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica.

Formulation of gastroretentive floating drug delivery system using hydrophilic polymers and its in vitro characterization

The aim of the present research is to formulate and evaluate the gastroretentive floating drug delivery system of antihypertensive drug, propranolol HCl. Gastroretentive floating tablets (GRFT) were prepared by using a synthetic hydrophilic polymer polyethylene oxide of different grades such as PEO WSR N-12 K and PEO 18 NF as release retarding polymers and calcium carbonate as gas generating agent. The GRFT were compressed by direct compression strategy and the tablets were evaluated for physico-chemical properties, in vitro buoyancy, swelling studies, in vitro dissolution studies and release mechanism studies. From the dissolution and buoyancy studies, F 9 was selected as an optimized formulation. The optimized formulation followed zero order rate kinetics with non-Fickian diffusion mechanism. The optimized formulation was characterised with FTIR studies and observed no interaction between the drug and the polymers.

O objetivo da presente pesquisa é o de formular e avaliar o sistema de liberação de fármaco gastrorretentivo flutuante, contendo o anti-hipertensivo, cloridrato de propranolol. Comprimidos gastrorretentivo flutuantes (GRFT) foram preparados utilizando um polímero hidrofílico sintético, o óxido de polietileno, de diferentes graus, tais como GE WSR N-12 K e GE 18 NF, como polímeros de retardamento de liberação, e carbonato de cálcio, como agente gerador de gases. Os GRFT foram comprimidos por compressão direta e avaliados para determinação das propriedades físico-químicas, flutuabilidade in vitro, estudos de inchamento, de dissolução in vitro e de mecanismo de liberação. Dos testes de dissolução e de flutuabilidade, selecionou-se F 9 como formulação otimizada. A formulação otimizada seguiu cinética de ordem zero, com mecanismo de difusão não-Fickiano. Essa formulação foi caracterizada por estudos de FTIR, não se observando interação entre o fármaco e os polímeros.

Design and evaluation of a gastroretentive drug delivery system for metformin HCl using synthetic and semi-synthetic polymers / Diseño y evaluación de un sistema gastro-retentivo de administración de metformina HCl, utilizando polímeros sintéticos y semisintéticos

The aim of the present research was to prepare and evaluate a gastroretentive drug delivery system for metformin HCl, using synthetic and semi-synthetic polymers. The floating approach was applied for preparing gastroretentive tablets (GRT) and these tablets were manufactured by the direct compression method. The drug delivery system comprises of synthetic and semi-synthetic polymers such as polyethylene oxide and Carboxymethyl ethyl cellulose (CMEC) as release-retarding polymers. GRT were evaluated for physico-chemical properties like weight variation, hardness, assay friability, in vitro floating behaviour, swelling studies, in vitro dissolution studies and rate order kinetics. Based upon the drug release and floating properties, two formulations (MP04 & MC03) were selected as optimized formulations. The optimized formulations MP04 and MC03 followed zero order rate kinetics, with non-Fickian diffusion and first order rate kinetics with erosion mechanism, respectively. The optimized formulation was characterised with FTIR studies and it was observed that there was no interaction between the drug and polymers.

El objetivo del presente trabajo consistió en preparar y evaluar un sistema de administración gastro-retentivo de metformina HCl, utilizando polímeros sintéticos y semisintéticos. Se aplicó el método de flotación para la elaboración de los comprimidos de retención gástrica (CRG) y éstos se prepararon mediante el método de compresión directa. El sistema de suministro del fármaco estaba constituido por polímeros sintéticos y semisintéticos, tales como el óxido de polietileno y la carboximetil etil celulosa, como agentes retardadores de la liberación del fármaco. Se evaluaron las propiedades físico-químicas de los CRG, tales como: variación de peso, dureza, friabilidad, comportamiento flotante in vitro, capacidad de inflación, estudios de disolución in vitro y su tasa de orden cinético. Se seleccionaron dos fórmulas (MP04 y MC03), sobre la base de la liberación del fármaco y las propiedades de flotabilidad, como fórmulas óptimas. Estas fórmulas MP04 y MC03 optimizadas siguieron cinéticas de velocidad de orden cero, con difusión no-Fickian y tasa cinética de primer orden con mecanismo de erosión, respectivamente. Las fórmulas óptimas se caracterizaron con estudios FTIR y se observó que no hubo interacción entre el fármaco y los polímeros.

Evaluation of antioxidant and mutagenic activities of honey-sweetened cashew apple nectar.

In vitro chemical properties and antioxidant potential and in vivo mutagenic activity of honey-sweetened cashew apple nectar (HSCAN), a beverage produced from the cashew pseudo-fruit (Anacardium occidentale L.) and of its constituents were assessed. Analytical procedures were carried out to investigate the honey used in the HSCAN preparation, and the results observed are in accordance with Brazilian legal regulations, except for diastase number. HSCAN and pulp were investigated for ascorbic acid, carotenoid, anthocyanin and total phenolic contents, and both showed high acid ascorbic concentrations. Antioxidant capacity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and/or ß-carotene/linoleic acid systems were applied and demonstrated a weak antioxidant capacity of honey and HSCAN, but cashew apple pulp demonstrated high antioxidant capacity. A weakly positive mutagenic effect of cashew pulp 20% was observed using the somatic mutation and recombination test (SMART) in Drosophila melanogaster only in the high-bioactivation (HB) cross. On the contrary, HSCAN was not mutagenic in both standard and high bioactivation crosses. HSCAN exhibited slight antioxidant activity, which could be associated with the high amount of ascorbic acid found in the samples evaluated. The beverage prepared did not induce DNA damage in somatic cells of D. melanogaster, which means that it is neither mutagenic nor recombinagenic in this test system.

Hydrogen peroxide production regulates the mitochondrial function in insulin resistant muscle cells: effect of catalase overexpression.

The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1α transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500µM) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with ß-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1α transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and ß-oxidation of fatty acids.