RESUMO
PURPOSE: 3D printing (3DP) makes it possible to obtain systems that are not achievable with current conventional methods, one of them, sustained release floating systems. Floating systems using ricobendazole (RBZ) as a model drug and a combination of polymers were designed and obtained by melt solidification printing technique (MESO-PP). METHODS: Four different MESO-PP inks were formulated based on combinations of the polymers Gelucire 43/01 and Gelucire 50/13 in different ratios. For each of the formulated inks, physicochemical characterization was performed by thermal analysis (thermogravimetric analysis [TGA] and differential scanning calorimetry [DSC]), fourier transform infrared spectrophotometer (FTIR) and X-ray diffraction (XRD). Pharmaceutical characterization was performed by in vitro assays to determine pharmaceutically relevant parameters. These parameters were calculated by applying mathematical models developed to evaluate in vitro drug release profiles. On the other hand, a physiologically based pharmacokinetic (PBPK) model was developed to predict the in vivo performance of RBZ loaded in the different inks by determining the Cmax, and the AUC0-∞. RESULTS: By increasing the proportion of Gelucire 50/13 co-surfactant in the mixtures (the proportion in Ink 1 was 33%, while the proportion in Ink 4 was 80%), the dissolution capacity of RBZ increases substantially, decreasing flotation times. CONCLUSION: MESO-PP produced ink 1 (50% Gelucire 43/01, 25% Gelucire 50/13 and 25% RBZ), which has a zero-order release (RR = 0.180%/min) and the longest flotation time (545 ± 23 min), and in turn would produce a significant increase in oral absorption of the drug, with an AUC0-∞ 2.16-fold higher than that obtained in animals treated with RBZ loaded in conventional tablets.
Assuntos
Excipientes , Tinta , Albendazol/análogos & derivados , Animais , Preparações de Ação Retardada/química , Excipientes/química , Polímeros , Impressão Tridimensional , Tensoativos , ComprimidosRESUMO
This paper describes a melting solidification printing process (MESO-PP) capable of obtaining printed oral solid dosage forms in a safe, versatile, and robust manner avoiding the use of solvents and high temperatures. MESO-PP and Gelucire® 50/13 (fatty polyethylene glycol esters) as ink can be used to obtain a floating sustained-release system with the aim of improving the dissolution and absorption of drugs, such as ricobendazole (RBZ), which have a low and erratic bioavailability. Gelucire 50/13 can be considered a good material to formulate inks using MESO-PP. As a model, the RBZ allowed us to assess that there were no changes in crystallinity and the API-ink interactions were ruled out using TGA, DSC, XRD and FT-IR assays. A batch of printlets, obtained using MESO-PP, fulfilled USP requirements regarding uniformity of mass (827 ± 9 mg) and drug content (211 ± 5 mg). Hardness and friability were 39.23 ± 9.65 N and 1.07 ± 0.5% respectively, just above the 1% USP tablet-friability limit. It was possible to obtain tablets of different sizes with high precision (r2 = 0.995). In vitro dissolution test showed that the printlet had a sustained-release of RBZ (only 7% after 15 min), that erosion was the predominant mechanism for drug release (n-value of Korsmeyer-Peppas equation = 0.991; r2 = 0.99) and that changes in the internal structures modify the release. Consequently, MESO-PP can be considered an excellent alternative to obtain solid pharmaceutical dosage forms with variable geometries for different pharmaceutical applications.
Assuntos
Impressão Tridimensional , Tecnologia Farmacêutica , Albendazol/análogos & derivados , Liberação Controlada de Fármacos , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos , TemperaturaRESUMO
Helminthic infections are produced by different types of worms and affect millions of people worldwide. Benzimidazole compounds such as ricobendazole (RBZ) are widely used to treat helminthiasis. However, their low aqueous solubility leads to poor gastrointestinal dissolution, absorption and potential lack of efficacy. The formulation of nanocrystals (NCs) have become the strategy of preference for hydrophobic drugs. In this work, we prepared RBZ NCs (RBZ-NCs) by an optimized combination of bead milling and spray-drying. Following the physicochemical characterization, a comparative pharmacokinetic evaluation of RBZ-NCs was performed in dogs using as controls a micronized powdered form of RBZ (mRBZ) and a physical mixture of drug and stabilizer 1:1 (PM). The particle size of the redispersed RBZ-NCs was 181.30 ± 5.93 nm, whereas DSC, PXRD and FTIR analyses demonstrated that the active ingredient RBZ remained physicochemically unchanged after the manufacture process. RBZ-NCs exhibited improved in vitro biopharmaceutical behaviour when compared to mRBZ. Consequently, the pharmacokinetic trial demonstrated a significant increase in the drug oral absorption, with an AUC0-∞ 1.9-fold higher in comparison to that obtained in animals treated with mRBZ. This novel formulation holds substantial potential for the development of new/alternative treatments for helminth infections both in human and veterinary medicine.
Assuntos
Albendazol/análogos & derivados , Nanopartículas/química , Tamanho da Partícula , Secagem por Atomização , Albendazol/síntese química , Albendazol/farmacocinética , Animais , Anti-Helmínticos/síntese química , Anti-Helmínticos/farmacocinética , Estudos Cross-Over , Cães , Feminino , MasculinoRESUMO
ABSTRACTAims: The main goal of the current study was to evaluate, on a commercial beef cattle farm, the impact of infection with gastrointestinal nematodes resistant to both ivermectin (IVM) and moxidectin (MXD) on the productivity of calves.Methods: Male Aberdeen Angus calves, aged 9-11 months, with faecal nematode egg counts (FEC) ≥200 epg and body weight ≥190â kg, were allocated to two herds. Herd A (n = 90) grazed a maize-winter forage crop rotation and Herd B (n = 90) grazed a 2-year-old Agropyrum pasture. On Day 0 in each herd, calves were randomly allocated into five groups (n = 18), which were treated with 0.2â mg/kg IVM; 0.2â mg/kg MXD; 3.75â mg/kg ricobendazole (RBZ), both IVM and RBZ, or remained untreated. Faecal samples collected on Days -1 and 19 were used to determine the percentage reduction in FEC, and genera of the nematodes were determined by the identification of the third-stage larvae recovered from faecal cultures. Total weight gain was determined from body weights recorded on Days -1 and 91.Results: Overall mean reduction in FEC was 42% for IVM, 67% for MXD, 97% for RBZ and 99% for IVM + RBZ. The reduction in FEC for Cooperia spp. was ≤78% for IVM and MXD, and for Haemonchus spp. was 0 and 36% for IVM and MXD, respectively, confirming the presence of parasites resistant to both anthelmintics. Only IVM + RBZ treatment resulted in 100% efficacy against Haemonchus spp. The overall estimated mean total weight gain for calves treated with IVM was 15.7 (95% CI = 11.9-19.7) kg and for calves treated with IVM + RBZ was 28.8 (95% CI = 25-32.5) kg (p < 0.001). Mean total weight gain for calves treated with MXD was 23.5 (95% CI = 19.7-27.2) kg.Conclusions and clinical relevance: In calves naturally infected with resistant nematodes, under the production system assessed here, weight gains were lower in calves treated with anthelmintics that were moderately or highly ineffective compared to those treated with highly effective anthelmintics. These results demonstrate to farmers and veterinarians the importance of a sustainable and effective nematode control under field conditions.
Assuntos
Albendazol/análogos & derivados , Antiparasitários/farmacologia , Doenças dos Bovinos/tratamento farmacológico , Ivermectina/farmacologia , Macrolídeos/farmacologia , Infecções por Nematoides/veterinária , Albendazol/farmacologia , Animais , Anti-Helmínticos/farmacologia , Antinematódeos/farmacologia , Argentina , Peso Corporal/efeitos dos fármacos , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/fisiopatologia , Resistência a Múltiplos Medicamentos , Quimioterapia Combinada/veterinária , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/fisiopatologia , Contagem de Ovos de Parasitas/veterinária , Carne VermelhaRESUMO
Nitazoxanide (NTZ) is a broad-spectrum drug used in intestinal infections, but still poorly explored in the treatment of parasitic tissular infections. This study aimed to evaluate the in vitro responses of the energetic metabolism of T. crassiceps cysticerci induced by NTZ. The organic acids of the tricarboxylic acid cycle, products derived from fatty acids oxidation and protein catabolism were analyzed. These acids were quantified after 24â¯h of in vitro exposure to different NTZ concentrations. A positive control group was performed with albendazole sulfoxide (ABZSO). The significant alterations in citrate, fumarate and malate concentrations showed the NTZ influence in the tricarboxylic acid (TCA) cycle. The non-detection of acetate confirmed that the main mode of action of NTZ is effective against T. crassiceps cysticerci. The statistical differences in fumarate, urea and beta-hydroxybutyrate concentrations showed the NTZ effect on protein catabolism and fatty acid oxidation. Therefore, the main energetic pathways such as the TCA cycle, protein catabolism and fatty acids oxidation were altered after in vitro NTZ exposure. In conclusion, NTZ induced a significant metabolic stress in the parasite indicating that it may be used as an alternative therapeutic choice for cysticercosis treatment. The use of metabolic approaches to establish comparisons between anti parasitic drugs mode of actions is proposed.
Assuntos
Antiparasitários/farmacologia , Taenia/efeitos dos fármacos , Tiazóis/farmacologia , Albendazol/análogos & derivados , Albendazol/farmacologia , Análise de Variância , Animais , Anti-Helmínticos/farmacologia , Citratos/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Meios de Cultura/química , Cysticercus/efeitos dos fármacos , Cysticercus/metabolismo , Metabolismo Energético/efeitos dos fármacos , Fumaratos/metabolismo , Ácidos Cetoglutáricos/metabolismo , Malatos/metabolismo , Neurocisticercose/tratamento farmacológico , Nitrocompostos , Ácido Oxaloacético/metabolismo , Ácido Succínico/metabolismo , Taenia/metabolismoRESUMO
Drug repositioning refers to the identification of new therapeutic indications for drugs already approved. Albendazole and ricobendazole have been used as anti-parasitic drugs for many years; their therapeutic action is based on the inhibition of microtubule formation. Therefore, the study of their properties as antitumor compounds and the design of an appropriate formulation for cancer therapy is an interesting issue to investigate. The selected compounds are poorly soluble in water, and consequently, they have low and erratic bioavailability. In order to improve their biopharmaceutics properties, several formulations employing cyclodextrin inclusion complexes were developed. To carefully evaluate the in vitro and in vivo antitumor activity of these drugs and their complexes, several studies were performed on a breast cancer cell line (4T1) and BALB/c mice. In vitro studies showed that albendazole presented improved antitumor activity compared with ricobendazole. Furthermore, albendazole:citrate-ß-cyclodextrin complex decreased significantly 4T1 cell growth both in in vitro and in vivo experiments. Thus, new formulations for anti-parasitic drugs could help to reposition them for new therapeutic indications, offering safer and more effective treatments by using a well-known drug.
Assuntos
Antiparasitários/administração & dosagem , Ciclodextrinas/administração & dosagem , Reposicionamento de Medicamentos/métodos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Albendazol/administração & dosagem , Albendazol/análogos & derivados , Albendazol/química , Animais , Antiparasitários/química , Disponibilidade Biológica , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Ciclodextrinas/química , Feminino , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Aleatória , Resultado do Tratamento , Neoplasias de Mama Triplo Negativas/patologia , Difração de Raios X , beta-Ciclodextrinas/administração & dosagem , beta-Ciclodextrinas/químicaRESUMO
Albendazole (ABZ) and ricobendazole (RBZ) are referred to as class II compounds in the Biopharmaceutical Classification System. These drugs exhibit poor solubility, which profoundly affects their oral bioavailability. Micellar systems are excellent pharmaceutical tools to enhance solubilization and absorption of poorly soluble compounds. Polysorbate 80 (P80), poloxamer 407 (P407), sodium cholate (Na-C), and sodium deoxycholate (Na-DC) have been selected as surfactants to study the solubilization process of these drugs. Fluorescence emission was applied in order to obtain surfactant/fluorophore (S/F) ratio, critical micellar concentration, protection efficiency of micelles, and thermodynamic parameters. Systems were characterized by their size and zeta potential. A blue shift from 350 to 345 nm was observed when ABZ was included in P80, Na-DC, and Na-C micelles, while RBZ showed a slight change in the fluorescence band. P80 showed a significant solubilization capacity: S/F values were 688 for ABZ at pH 4 and 656 for RBZ at pH 6. Additionally, P80 micellar systems presented the smallest size (10 nm) and their size was not affected by pH change. S/F ratio for bile salts was tenfold higher than for the other surfactants. Quenching plots were linear and their constant values (2.17/M for ABZ and 2.29/M for RBZ) decreased with the addition of the surfactants, indicating a protective effect of the micelles. Na-DC showed better protective efficacy for ABZ and RBZ than the other surfactants (constant values 0.54 and 1.57/M, respectively), showing the drug inclusion into the micelles. Entropic parameters were negative in agreement with micelle formation.
Assuntos
Albendazol/análogos & derivados , Albendazol/química , Ácido Desoxicólico/química , Fluorescência , Micelas , Poloxâmero/química , Polissorbatos/química , Colato de Sódio/química , Solubilidade , Espectrometria de Fluorescência , Tensoativos/química , TermodinâmicaRESUMO
The goals of the current study were to evaluate the potential pharmacokinetic (PK) interactions and the clinical efficacy occurring after the subcutaneous (s.c.) administration of ricobendazole (RBZ) and levamisole (LEV) given both separately and co-administered to calves naturally infected with susceptible gastrointestinal nematodes. The clinical efficacy was shown in two seasons, winter and spring, with predominance of different nematode populations. Groups of 15 calves were treated with RBZ alone, LEV alone and RBZ + LEV combination, and an untreated group was kept as a Control. RBZ and LEV plasma concentrations were quantified by HPLC. The clinical efficacy was determined by the faecal egg count reduction test. RBZ and LEV have similar plasma persistence, being detected in plasma over 24 hr post-treatment. No PK interactions were observed after the combined treatment, with similar PK parameters (p > .05) obtained for the single-drug and the combination-based strategy. In winter, the observed clinical efficacies were 96%, 99% and 100% for groups treated with RBZ, LEV and RBZ + LEV, respectively; however, in spring, the efficacies were 95%, 93% and 96% for the same groups. Remarkably, the combination was the only treatment that achieved 100% clinical efficacy against both Haemonchus spp and Ostertagia spp in winter; but the increased presence of Ostertagia spp. in spring (28% in untreated group) determined a tendency to reduced efficacies compared to winter time (only 10% of Ostertagia spp. in untreated group), even for the combined treatment. Overall, in a scenario where the nematode population is susceptible, the RBZ + LEV treatment may be a valid combination in cattle to delay the development of resistance, especially in winter when this combination achieved 100% of efficacy. Thus, selection of anthelmintic resistance will never occur. In fact, this is one of the greatest challenges for the whole cattle production system: to be one step ahead of anthelmintic resistance.
Assuntos
Albendazol/análogos & derivados , Antinematódeos/uso terapêutico , Levamisol/uso terapêutico , Albendazol/administração & dosagem , Albendazol/sangue , Albendazol/uso terapêutico , Animais , Antinematódeos/administração & dosagem , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Quimioterapia Combinada/veterinária , Hemoncose/tratamento farmacológico , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Injeções Subcutâneas/veterinária , Levamisol/administração & dosagem , Levamisol/sangue , Masculino , Ostertagia/efeitos dos fármacos , Ostertagíase , Contagem de Ovos de Parasitas/veterinária , Estações do AnoRESUMO
This paper describes the development of analytical methods for the quantification of albendazole (ABZ) in fish feed and ABZ and its main known metabolites (albendazole sulfoxide, albendazole sulfone and albendazole aminosulfone) in fish fillet employing LC-MS/MS. In order to assess the reliability of the analytical methods, evaluation was undertaken as recommended by related guides proposed by the Brazilian Ministry of Agriculture for analytical method validation. The calibration curve for ABZ quantification in feed showed adequate linearity (r > 0.99), precision (CV < 1.03%) and trueness ranging from 99% to 101%. The method for ABZ residues in fish fillet involving the QuEChERS technique for sample extraction had adequate linearity (r > 0.99) for all analytes, precision (CV < 13%) and trueness around 100%, with CCα < 122 ng g-1 and CCß < 145 ng g-1. Besides, by aiming to avoid the risk of ABZ leaching from feed into the aquatic environment during fish medication via the oral route, a promising procedure for drug incorporation in the feed involving coating feed pellets with ethyl cellulose polymer containing ABZ was also evaluated. The medicated feed had good homogeneity (CV < 3%) and a lower release of ABZ (< 0.2%) from feed to water when the medicated feed stayed in the water for up to 15 min.
Assuntos
Albendazol/análogos & derivados , Albendazol/análise , Ração Animal/análise , Anti-Helmínticos/análise , Resíduos de Drogas/análise , Carne/análise , Albendazol/administração & dosagem , Albendazol/metabolismo , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/metabolismo , Biotransformação , Brasil , Celulose/análogos & derivados , Celulose/química , Caraciformes , Cromatografia Líquida , Materiais Revestidos Biocompatíveis/química , Liberação Controlada de Fármacos , Resíduos de Drogas/metabolismo , Guias como Assunto , Humanos , Cinética , Limite de Detecção , Extração Líquido-Líquido/métodos , Espectrometria de Massas em TandemRESUMO
1. Precision-cut liver slices (PCLS) from food-producing animals have not been extensively used to study xenobiotic metabolism, and thus information on this field of research is sparse. 2. The aims of the present work were to further validate the technique of production and culture of bovine PCLS and to characterize the metabolic interaction between the anthelmintic albendazole (ABZ) and the flavin-monooxygenase (FMO) inhibitor methimazole (MTZ). 3. Nine steers were used as donors. PCLS were produced and incubated under two methods: a dynamic organ culture (DOC) incubator and a well-plate (WP) system. 4. Tissue viability, assessed through both structural and functional markers, was preserved throughout 12 h of incubation. ABZ was metabolized to its (+) and (-) albendazole sulfoxide stereoisomers (ABZSO) in bovine PCLS. The interaction between ABZ and MTZ resulted in a reduction (p < 0.001) in the rates of appearance of (+) ABZSO. Conversely, in presence of MTZ, the rates of appearance of (-) ABZSO increased under both systems (p < 0.05). 5. Both culture systems were suitable for assessing the interaction between ABZ and MTZ. 6. Overall, the results presented herein show that PCLS are a useful and reliable tool for short-term studies on metabolic drug-drug interactions in the bovine species.
Assuntos
Interações Medicamentosas , Fígado/metabolismo , Administração Oral , Albendazol/análogos & derivados , Albendazol/metabolismo , Animais , Anti-Helmínticos/metabolismo , Bovinos , Metimazol/metabolismo , Microssomos Hepáticos/metabolismo , EstereoisomerismoRESUMO
Nitazoxanide (NTZ) is a broad-spectrum anti-parasitic drug used against a wide variety of protozoans and helminthes. Albendazole, its active metabolite albendazole sulfoxide (ABZSO), is one of the drugs of choice to treat both intestinal and tissue helminth and protozoan infections. However little is known regarding their impact on the metabolism of parasites. The aim of this study was to compare the in vitro effect of NTZ and ABZSO in the glycolysis of Taenia crassiceps cysticerci. The cysticerci were treated with 1.2; 0.6; 0.3 or 0.15 µg/mL of NTZ or ABZSO. Chromatographic and spectrophotometric analyses were performed in the culture medium and in the cysticerci extract. Regarding the glucose concentrations was possible to observe two responses: impair of the uptake and gluconeogenesis. The pyruvate concentrations were increased in the ABZSO treated group. Lactate concentrations were increased in the culture medium of NTZ treated groups. Therefore it was possible to infer that the metabolic acidosis was greater in the group treated with NTZ than in the ABZSO treated group indicating that this is one of the modes of action used by this drug to induce the parasite death.
Assuntos
Albendazol/análogos & derivados , Antiparasitários/farmacologia , Taenia/efeitos dos fármacos , Tiazóis/farmacologia , Albendazol/farmacologia , Animais , Anticestoides/farmacologia , Feminino , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Ácido Láctico/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nitrocompostos , Ácido Pirúvico/metabolismo , Taenia/crescimento & desenvolvimento , Taenia/metabolismoRESUMO
1. To optimise the use of albendazole (ABZ) as an anthelmintic in hens, the effects of fasting and type of diet on the plasma kinetics of ABZ and its metabolites were evaluated. 2. Twenty-four hens were distributed into 4 groups: In experiment I the Fed group were fed ad libitum, while the Fasted group was fasted over a 12-h period. In experiment II the Pelleted group was fed with pelleted commercial food, while the Grain group was fed with cereal grains. All the groups were treated with ABZ by oral route. Blood samples were taken and plasma analysed by HPLC. 3. ABZ and its metabolites albendazole-sulphoxide (ABZSO) and albendazole-sulphone (ABZSO2) were recovered in plasma in all the groups. The 12-h fasting period did not modify the disposition kinetics of ABZ in hens. The type of feed affected ABZ kinetics. ABZSO concentration profile was higher and detected for longer in the Grain group compared to the Pelleted group. Statistical differences were not found for AUC0-∞ values, whereas the T1/2for and T1/2el were different between groups. 4. Factors affecting ABZ kinetic behaviour should be taken into account to optimise its use to ensure the sustainability of the limited available anthelmintic therapeutic tools in avian parasite control.
Assuntos
Albendazol/farmacocinética , Anti-Helmínticos/farmacocinética , Galinhas/metabolismo , Albendazol/análogos & derivados , Albendazol/sangue , Animais , Anti-Helmínticos/sangue , Galinhas/sangue , Galinhas/fisiologia , Dieta/veterinária , Feminino , Privação de Alimentos/fisiologiaRESUMO
Cystic echinococcosis is a chronic, complex, and still neglected disease. Although albendazole has demonstrated efficacy, only about one-third of patients experience complete remission or cure and 30-50% of treated patients develop some evidence of a therapeutic response. Different strategies have been developed in order to improve the albendazole water solubility and dissolution rate. The aim of the current work was to investigate the chemoprophylactic and clinical efficacy of an albendazole:poloxamer 188 solid dispersion formulation on mice infected with Echinococcus granulosus metacestodes. Albendazole formulated as solid dispersion had greater chemoprophylactic and clinical efficacy than albendazole alone. The improved in therapeutic efficacy could be a consequence of the increase in the systemic availability of albendazole sulfoxide. The work reported here demonstrates that in vivo treatment with albendazole:poloxamer 188 impairs the development of the hydatid cysts. This new pharmacotechnically based strategy could be a suitable alternative for treating cystic echinococcosis in humans.
Assuntos
Albendazol/análogos & derivados , Quimioprevenção , Equinococose/tratamento farmacológico , Echinococcus granulosus , Poloxâmero/química , Albendazol/química , Albendazol/farmacologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Equinococose/prevenção & controle , Echinococcus granulosus/efeitos dos fármacos , Echinococcus granulosus/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Resultado do TratamentoRESUMO
The goals of the current trial were (a) to characterize the plasma disposition kinetics of levamisole (LEV), albendazole (ABZ) and ivermectin (IVM), each administered either alone (single active ingredient) or as a combined formulation to lambs; (b) to compare the clinical anthelmintic efficacy of the same drugs given either separately or co-administered to lambs infected with resistant nematodes. Fifty Corriedale lambs naturally infected with multiple resistant gastrointestinal nematodes were involved in the following experimental trials: (a) "Pharmacokinetic trial": the animals were allocated into five groups (n=10 each) and intraruminally treated with either LEV (8 mg/kg), ABZ (5mg/kg), IVM (0.2mg/kg), or with a LEV+ABZ+IVM combined formulation, where each active ingredient was administered at the same dose. Blood samples were collected over 15 days post-treatment and drug plasma concentrations measured by HPLC. (b) "Efficacy trial": the same treated groups plus an untreated control group were used to assess the comparative anthelmintic efficacy by the faecal egg count reduction test (FECRT). Although the overall LEV disposition kinetics was unaffected, significantly lower (61%) ABZ-sulphoxide and higher (71%) IVM systemic availabilities were obtained after administration of the combined formulation in comparison to those obtained after treatment with each drug alone. A multiple drug resistance situation was observed for Haemonchus spp. The observed efficacies were 52% (LEV), 72% (ABZ), 80% (IVM) and 87% (triple combined formulation). The results reported here contribute to the pharmaco-therapeutic knowledge on drug combinations. This type of research is crucial before further development of combined anthelmintic preparations reaches the market to deal with resistant nematode control. The co-administration of LEV+ABZ+IVM did not result in a significant advantageous anthelmintic effect compared to the treatment with IVM alone. The simultaneous/combined administration of LEV, ABZ and IVM may account for a drug-drug pharmacological interaction in infected lambs. The pharmacokinetic interaction accounted for a reduced ABZ-sulphoxide and enhanced IVM systemic exposure following the combined treatment.
Assuntos
Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/farmacocinética , Infecções por Nematoides/veterinária , Doenças dos Ovinos/tratamento farmacológico , Albendazol/administração & dosagem , Albendazol/análogos & derivados , Albendazol/sangue , Albendazol/farmacocinética , Animais , Anti-Helmínticos/sangue , Anti-Helmínticos/farmacologia , Área Sob a Curva , Interações Medicamentosas , Resistência a Medicamentos/efeitos dos fármacos , Fezes/parasitologia , Feminino , Ivermectina/administração & dosagem , Ivermectina/sangue , Ivermectina/farmacologia , Levamisol/administração & dosagem , Levamisol/sangue , Levamisol/farmacocinética , Masculino , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Contagem de Ovos de Parasitas/veterinária , Ovinos , TempoRESUMO
Microsporidia comprise a large group of obligate intracellular parasites. The microsporidian Encephalitozoon cuniculi causes disseminated infection in immunosuppressed patients with HIV, cancer, or transplants and in the elderly. In vivo and in vitro studies on the effectiveness of drugs are controversial. Currently, there is no effective treatment. We tested albendazole, albendazole sulfoxide, metronidazole, and cyclosporine in mice immunosuppressed with cyclophosphamide and inoculated by the intraperitoneal route with 10(7) E. cuniculi spores. One week after experimental inoculation, the mice were treated with albendazole, albendazole sulfoxide, metronidazole, and cyclosporine. Histological and morphometric analyses were performed to compare the treated groups. The state of immunosuppression was evaluated by phenotyping CD4(+) and CD8(+) T cells by flow cytometry. Nontreated mice showed acute disseminated and fatal encephalitozoonosis. The treatment with benzimidazoles significantly reduced infection until 30 days posttreatment (p.t.), but at 60 days p.t., the infection had recurred. Metronidazole decreased infection by a short time, and cyclosporine was not effective. All animals were immunosuppressed by all the experiments, as demonstrated by the low number of CD4(+) and CD8(+) T cells. We conclude that no drug was effective against E. cuniculi, but the benzimidazoles controlled the infection transiently.
Assuntos
Albendazol/análogos & derivados , Albendazol/uso terapêutico , Ciclosporina/uso terapêutico , Encefalitozoonose/tratamento farmacológico , Metronidazol/uso terapêutico , Albendazol/farmacologia , Animais , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Ciclofosfamida/farmacologia , Ciclofosfamida/uso terapêutico , Ciclosporina/farmacologia , Encephalitozoon cuniculi/efeitos dos fármacos , Hospedeiro Imunocomprometido , Intestinos/microbiologia , Intestinos/patologia , Rim/microbiologia , Rim/patologia , Fígado/microbiologia , Fígado/patologia , Pulmão/microbiologia , Pulmão/patologia , Masculino , Metronidazol/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Baço/microbiologia , Baço/patologiaRESUMO
Helminth ß-tubulins are the targets of benzimidazole (BZM) carbamate compounds. The specificity of the interactions between such compounds and their in vivo targets depends on the presence of specific amino acid residues in the target molecules. To discover new and effective anthelmintic drugs, we used a medicinal chemistry approach to synthesize a series of BZM derivatives that exploited the BZM moiety as a template. We have previously found that one compound, 2-(trifluoromethyl)-1H-benzimidazole (RCB20), has better in vitro and in vivo activity than albendazole sulfoxide (ABZSO). In the present study, the effect of RCB20 and ABZSO treatment on expression of Taenia crassiceps cysticerci cytoskeletal proteins such as actin, myosin II, and tubulin isoforms was examined. The effects of RCB20 and ABZSO after 11 days treatment of the parasites was evaluated by light, confocal, and electron microscopy, and by immunochemistry and immunohistochemistry. The RCB20-induced effects were more rapid than the ABZSO-induced effects on the parasites. In the RCB20-treated parasites, we observed gross-structural damage at the whole parasite level, particularly in the inner tissues and flame cells. Changes in the expression patterns of the cytoskeletal proteins, as assessed by immunohistochemistry and immunoblotting, revealed that the most important drug-induced effect on the parasites was a reduction in the expression level of tyrosinated α-tubulins. Our research findings suggest that RCB20 treatment affected posttranslational modification of parasite α-tubulin molecules, which involved removal of the α-tubulin carboxy-terminal tyrosine.
Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Expressão Gênica/efeitos dos fármacos , Taenia/efeitos dos fármacos , Tubulina (Proteína)/biossíntese , Actinas/biossíntese , Albendazol/análogos & derivados , Albendazol/farmacologia , Animais , Cysticercus/anatomia & histologia , Cysticercus/efeitos dos fármacos , Imunoquímica , Microscopia , Miosina Tipo II/biossíntese , Taenia/anatomia & histologiaRESUMO
Analytical and semipreparative high performance liquid chromatography methods using polysaccharide-based chiral stationary phases were developed for the enantiomeric resolution of albendazol sulfoxide. The enantioseparation of this compound was evaluated with four chiral stationary phases: cellulose and amylose tris(3,5-dimethylphenylcarbamate), amylose tris[(S)-1-phenylethylcarbamate] and amylose tris(3,5-dimethoxyphenylcarbamate), under three elution conditions: normal, reversed-phase and polar organic mode. The influences of the mobile phase and of the structure of the chiral stationary phase on the enantiomeric separation are discussed. The best chiral performances were achieved on an amylose tris(3,5-dimethylphenylcarbamate) phase under normal (R(s)=4.96) and polar organic mode (R(s)=2.60 and 3.09). A polar organic condition using methanol as mobile phase offered shorter retention factors (k(1)=0.34) and was scaled up to semipreparative HPLC to obtain milligram quantities of both albendazole sulfoxide enantiomers for further in vitro studies. Optical rotation and circular dichroism of both enantiomers of albendazole sulfoxide was determined. The compounds ABZ, ABZ-SO, (R)-(+)-ABZ-SO and (S)-(-)-ABZ-SO were all evaluated regarding their capacity to inhibit the in vitro growth of three human tumor cell lines: MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and A375-C5 (melanoma). In addition, the effect of the (R)-(+)-ABZ-SO compound in the cell cycle profile and apoptosis of MCF-7 cells were also studied. Results indicated that compound ABZ was the most potent regarding cell growth inhibition and that the (+)-(R)-ABZ was a more potent inhibitor of cell growth than the (S)-(-)-ABZ-SO, particularly in the MCF-7 cell line. In addition, the (R)-(+)-ABZ-SO significantly increased the levels of apoptosis of the MCF-7 cells.
Assuntos
Albendazol/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Neoplasias/tratamento farmacológico , Albendazol/química , Albendazol/farmacologia , Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dicroísmo Circular/métodos , Humanos , Neoplasias/patologia , Rotação Ocular , EstereoisomerismoRESUMO
The enantiomeric separation of albendazole sulfoxide was carried out by simulated moving bed chromatography with variable zones (VARICOL). An overall recovery of 97% was achieved and enantiomeric ratios of 99.5% for raffinate and 99.0% for extract were attained. A total of 880 mg of (+)-albendazol sulfoxide and 930 mg of its antipode were collected after 55 cycles or 11 h of process, resulting in a mass rate of 2 g/day. Furthermore the absolute configuration of the enantiopure compounds was determined for the first time by vibrational circular dichroism (VCD) with the aid of theoretical calculations as (-)-(S) and (+)-(R)-albendazole sulfoxide.
Assuntos
Albendazol/análogos & derivados , Cromatografia/métodos , Albendazol/química , Albendazol/isolamento & purificação , Dicroísmo Circular , Conformação Molecular , EstereoisomerismoRESUMO
A high-performance liquid chromatographic method using polar organic mode was developed to analyze albendazole (ABZ), albendazole sulfone (ABZSO(2)) and the chiral and active metabolite albendazole sulfoxide (ABZSOX, ricobendazole) that was further applied in stereoselective fungal biotransformation studies. The chromatographic separation was performed on a Chiralpak AS column using acetonitrile:ethanol (97:3, v/v) plus 0.2% triethylamine and 0.2% acetic acid as the mobile phase at a flow rate of 0.5 mL min(-1). The present study employed hollow fiber liquid-phase microextraction as sample preparation. The method showed to be linear over the concentration range of 25-5000 ng mL(-1) for each ABZSOX enantiomer, 200-10,000 ng mL(-1) for ABZ and 50-1000 ng mL(-1) for ABZSO(2) metabolite with correlation coefficient (r)>0.9934. The mean recoveries for ABZ, rac-ABZSOX and ABZSO(2) were, respectively, 9%, 33% and 20% with relative standard deviation below 10%. Within-day and between-day precision and accuracy assays for these analytes were studied at three concentration levels and were lower than 15%. This study opens the door regarding the possibility of using fungi in obtaining of the active metabolite ricobendazole. Nigrospora sphaerica (Sacc.) E. W. Mason (SS67), Pestalotiopsis foedans (VR8), Papulaspora immersa Hotson (SS13) and Mucor rouxii were able to stereoselectively metabolize ABZ into its chiral metabolite. Among them, the fungus Mucor rouxii was the most efficient in the production of (+)-ABZSOX.
Assuntos
Albendazol/análogos & derivados , Albendazol/metabolismo , Ascomicetos/metabolismo , Albendazol/química , Ascomicetos/química , Biotransformação/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , EstereoisomerismoRESUMO
The gastrointestinal absorption of most drugs follows a first-order kinetics, whereby a constant fraction of the total drug is absorbed in each equal time interval. Although this related absorption principle is applicable to the most of the therapeutically used drugs, it remains unclear for poorly water-soluble compounds such as the benzimidazole anthelmintics in ruminants. The goal of the current work was to characterize the albendazole (ABZ) metabolites plasma disposition kinetics after ABZ administration at different dosages to nematode-infected lambs. Eighteen Corriedale lambs artificially infected with a resistant Haemonchus contortus strain were allocated into three groups and intraruminally treated with ABZ at either 5 (ABZ(5)), 15 (ABZ(15)) or 45 (ABZ(45)) mg/kg. Blood samples were collected up to 120 h post-treatment, and the collected plasma was analysed by high-performance liquid chromatography. The estimated pharmacokinetic parameters were statistically compared using parametric and nonparametric tests. None of the animals involved in the current trial showed any adverse events during the study. While ABZ parent drug was not recovered in the bloodstream, the area under the concentration vs time curve (AUC) of the active ABZ-sulphoxide (ABZSO) metabolite increased significantly (P<0.05) from 21.0 (ABZ(5)) up to 158.6 (ABZ(15)) and 389.7 µg·h/mL (ABZ(45)), which indicates some type of nonproportionality in the relationship between dose level and drug systemic exposure. The overall kinetic disposition of the inactive sulphone metabolite did not change after treatment at threefold the therapeutic ABZ dosage. However, significantly (P<0.05) higher AUC, C(max) and mean residence time values were observed after the administration of the highest dosage level. The higher dosages accounted for a significantly (P<0.05) enhancement of the ABZSO peak plasma concentration, which were obtained at delayed times post-treatment. High correlations between AUC(0-LOQ) and C(max) and nematode counts were observed, with Spearman's coefficients of -0.83 and -0.84, respectively. The results obtained in the current experiment show that increasing the dose of ABZ in sheep is clearly associated with enhanced plasma ABZ metabolites exposure. The data showed a nonproportionality on the gastrointestinal absorption of ABZ in nematode-infected lambs.