RESUMO
Six esterase inhibitors, namely EDTA·2Na(+), NaF, phenylmethanesulfonyl fluoride, dichlorvos, bis-nitrophenyl phosphate (BNPP) and thenoyltrifluoroacetone, and the mixture of NaF and BNPP, were evaluated for the stabilization of labile benzoate containing zeylenone in rat plasma. The mixture appeared to exhibit the most effectively stabilizing effect with the degraded content of zeylenone decreasing from >60% (in the absence of inhibitors) to <6%. Following the stabilization by the addition of NaF (5 mM) and BNPP (5 mM), the analytes in rat plasma were acidified by formic acid and extracted into ethyl acetate at 0°C. After chromatographic separation, the detection of zeylenone was performed on a 3200 Q-Trap with positive ion electrospray mode, monitoring the ion transition m/z 383.2 â 105.0. The method was validated over the range from 2.68 to 1340 ng/mL with inter- and intra-run precision for the quality control samples being less than 6.8%. The assay accuracy was within 100 ± 7.0%. The validated method was successfully applied to a pharmacokinetic study in rats after the intratracheal administration of zeylenone in free drug or polymeric micellar solutions. The results showed that the pulmonary absorption of zeylenone loaded in micelles was significantly retarded compared with that of free drug solutions.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cicloexanos/sangue , Dioxanos/sangue , Inibidores Enzimáticos/farmacologia , Esterases/antagonistas & inibidores , Espectrometria de Massas em Tandem/métodos , Administração por Inalação , Animais , Benzoatos/química , Cicloexanos/administração & dosagem , Cicloexanos/química , Cicloexanos/farmacocinética , Dioxanos/administração & dosagem , Dioxanos/química , Dioxanos/farmacocinética , Estabilidade de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Masculino , Nitrofenóis/química , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fluoreto de Sódio/química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
The objectives of this study were to investigate the effects of mucoadhesive excipients on systemic bioavailability of an inhaled drug and to evaluate the feasibility of using the pulmonary route for non-invasive systemic delivery of scutellarin, a poorly orally absorbed flavonoid glucuronide. Following intratracheal spray of the scutellarin solution, the bioavailability was found to be approximately 77% in rats, which was >30-fold higher than that via the peroral route. In addition, the pulmonary absorption of scutellarin appeared to avoid the intestinal first-pass metabolism accompanied by peroral administration. Spray-dried scutellarin particles with the presence of mucoadhesive excipients were found to affect the corresponding mucociliary transport rate (MTR) as evaluated by a frog palate model. The pharmacokinetic results indicated that the magnitude of AUC(0-480) of intrapulmonary delivered drug particles was not correlated to the fine particle fraction (FPF) but inversely related to the MTR. Incorporating mucoadhesive polymeric mixtures into the scutellarin particles, the MTR decreased by sixfold, and the absolute bioavailability of the drug was found to increase from 70.1% to 97.9% despite a decrease in the FPF. Moreover, in vitro results evaluated using Calu-3 and A549 cell lines showed that scutellarin and spray-dried particles with or without the presence of mucoadhesives exhibited no local cell cytotoxic effects in the tested concentration range. In conclusion, the conducting airway is well permeable to scutellarin, and scutellarin may be effectively delivered systemically through inhalation of respirable droplets or particles.
Assuntos
Apigenina/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , Excipientes/química , Glucuronatos/administração & dosagem , Adesividade , Administração por Inalação , Administração Oral , Aerossóis , Animais , Apigenina/química , Apigenina/farmacocinética , Apigenina/toxicidade , Disponibilidade Biológica , Bufonidae , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacocinética , Medicamentos de Ervas Chinesas/toxicidade , Excipientes/toxicidade , Estudos de Viabilidade , Glucuronatos/química , Glucuronatos/farmacocinética , Glucuronatos/toxicidade , Humanos , Ácido Hialurônico/química , Injeções Intravenosas , Masculino , Teste de Materiais , Depuração Mucociliar , Tamanho da Partícula , Permeabilidade , Álcool de Polivinil/química , Povidona/química , Ratos , Ratos Wistar , Mucosa Respiratória/metabolismo , Propriedades de SuperfícieRESUMO
The objective of this study was to prepare solid lipid nanoparticles (SLNs) for sustained pulmonary delivery of Yuxingcao essential oil (YEO). Three YEO loaded SLNs (SLN-200, SLN-400 and SLN-800) with different particle size were prepared and separated following a high-shear homogenization technique using Compritol 888 ATO as lipid and polyvinyl alcohol as an emulsifier. The particle size, zeta potential, drug encapsulation efficiency and drug loading of the SLNs were determined to be between 171 and 812nm, -17.1 and -19.3mV, between 76.6 and 90.2% and between 2.34 and 3.12%, respectively whereas the in vitro release data showed that the SLNs led to sustained drug release up to 48h. In addition, the SLN suspensions after nebulization conferred the fine particle fractions (<5.4µm) of 67.4-75.8%. Following intratracheal administration to rats, YEO loaded SLNs not only prolonged pulmonary retention up to 24h, but also increased AUC values (15.4, 18.2 and 26.3µg/gh for SLN-200, SLN-400 and SLN-800, respectively) by 4.5-7.7 folds compared to the intratracheally dosed YEO solution and by 257-438 folds to the intravenously dosed YEO solution, respectively. The present results were the first to show that YEO loaded SLNs may sustain YEO inhalation delivery and improve local bioavailability, representing a promising inhalable carrier to attain once daily application.
Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Lipídeos/química , Nanopartículas , Óleos Voláteis/administração & dosagem , Animais , Área Sob a Curva , Disponibilidade Biológica , Química Farmacêutica/métodos , Preparações de Ação Retardada , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Medicamentos de Ervas Chinesas/farmacocinética , Ácidos Graxos/química , Pulmão/metabolismo , Masculino , Óleos Voláteis/farmacocinética , Tamanho da Partícula , Álcool de Polivinil/química , Ratos , Ratos Wistar , Fatores de Tempo , Distribuição TecidualRESUMO
Polymeric micelles are considered promising carriers for pulmonary drug delivery. Their interaction with the respiratory epithelium, however, is mostly unknown. In the present study, methoxypoly (ethylene glycol) (mPEG)-poly (lactic-co-glycolic acid) (PLGA) micelles containing curcumin acetate (CA) or a mixture of CA and Nile Red (NR) were prepared using the solvent evaporation method. Calu-3 and NCI-H441 human respiratory epithelial cell monolayers were used as in vitro models of upper and lower respiratory tract epithelium barrier, respectively, to study the cellular uptake and transport of the vesicles. The results show that Calu-3 and NCI-H441 cells internalized micellar particles and that micelles were able to translocate across the cell monolayers. Micelles were more readily internalized into and permeated across Calu-3 cell monolayers when compared to NCI-H441 cells. Furthermore, the presence of inhibitors of endocytic processes, such as methyl-ß-cyclodextrin, NaN3 and hypertonic sucrose attenuated the cellular uptake and trafficking of micelles. In conclusion, this study demonstrated that mPEG-PLGA micelles translocate human respiratory epithelium in vitro through clathrin-, energy- and cholesterol-mediated endocytosis.
Assuntos
Células Epiteliais/metabolismo , Poliésteres/farmacocinética , Polietilenoglicóis/farmacocinética , Mucosa Respiratória/metabolismo , Transporte Biológico Ativo , Linhagem Celular , Curcumina/administração & dosagem , Curcumina/farmacocinética , Endocitose/efeitos dos fármacos , Humanos , Micelas , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacosRESUMO
The objective of the present study was to investigate the physical stability of spray-dried proteins within surfactant-free hydrofluoroalkane (HFA) pressurised metered dose inhalers (pMDIs) during prolonged storage. Two model proteins (lysozyme and catalase) were spray-dried and stabilised in the presence of excipients, and subsequently suspended within HFA 134a. The pMDIs were stored valve-up for 6 months at room temperature (ca. 25 degrees C). Activities of the proteins were determined using biological assays and the fine particle fraction of the pMDIs was measured using a twin-stage impinger. The biological activities of catalase and lysozyme were found to be preserved in the presence of sugars and/or 80% hydrolysed polyvinyl alcohol (PVA) during spray drying. In addition, suspending the stabilised proteins within HFA for up to 6 months had little effect on their activity. The aerosolisation performance of lysozyme or catalase formulations containing either sucrose or trehalose as stabilisers appeared to deteriorate as a function of storage time. However, those formulations containing PVA were found to generate the greatest fine particle fraction, which in some cases was up to 50%, and to possess excellent physical stability during storage. The results indicated that the presence of PVA in the spray-dried stabilised protein particles could enhance the physical stability of particles, when suspended in the surfactant-free HFA MDI formulations, without affecting the protein stability upon prolonged storage.
Assuntos
Propelentes de Aerossol/química , Excipientes/química , Hidrocarbonetos Fluorados/química , Inaladores Dosimetrados , Álcool de Polivinil/química , Proteínas/química , Catalase/química , Catalase/ultraestrutura , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Microscopia Eletrônica de Varredura , Muramidase/química , Muramidase/ultraestrutura , Tamanho da Partícula , Proteínas/ultraestrutura , Propriedades de SuperfícieRESUMO
Hyaluronic acid (HA), is a polyanionic polysaccharide that consists of N-acetyl-D-glucosamine and beta-glucoronic acid. It is most frequently referred to as hyaluronan because it exists in vivo as a polyanion and not in the protonated acid form. HA is distributed widely in vertebrates and presents as a component of the cell coat of many strains of bacteria. Initially the main functions of HA were believed to be mechanical as it has a protective, structure stabilizing and shock-absorbing role in the body. However, more recently the role of HA in the mediation of physiological functions via interaction with binding proteins and cell surface receptors including morphogenesis, regeneration, wound healing, and tumor invasion, as well as in the dynamic regulation of such interactions on cell signaling and behavior has been documented. The unique viscoelastic nature of hyaluronan along with its biocompatibility and nonimmunogenicity has led to its use in a number of cosmetic, medical, and pharmaceutical applications. More recently, HA has been investigated as a drug delivery agent for ophthalmic, nasal, pulmonary, parenteral, and dermal routes. The purpose of our review is to describe the physical, chemical, and biological properties of native HA together with how it can be produced and assayed along with a detailed analysis of its medical and pharmaceutical applications.
Assuntos
Sistemas de Liberação de Medicamentos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Animais , Sequência de Carboidratos , Implantes de Medicamento/administração & dosagem , Implantação do Embrião/efeitos dos fármacos , Terapia Genética , Humanos , Ácido Hialurônico/administração & dosagem , Ácido Hialurônico/metabolismo , Lipossomos , Dados de Sequência Molecular , Soluções Oftálmicas/administração & dosagem , Osteoartrite/tratamento farmacológico , Veículos Farmacêuticos/administração & dosagem , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismo , Cicatrização/efeitos dos fármacosRESUMO
Polymeric micelles represent interesting delivery systems for pulmonary sustained release. However, little is known about their in vivo release and translocation profile after delivery to the lungs. In the present study, curcumin acetate (CA), which is an ester prodrug of curcumin, or the mixture of CA and Nile red was encapsulated into PEGPLGA micelles by a solvent evaporation method. The micellar formulation increased the stability of CA in water and physiologically relevant fluids and led to a sustained drug release in vitro. Following intratracheal (IT) administration to rats, CA loaded micelles achieved not only prolonged pulmonary retention with AUC values almost 400-fold higher than by IV route, but also local sustained release up to 24 h. In addition, IT delivery of micelles appeared to facilitate the uptake into the pulmonary vascular endothelium and efficiently translocate across the airblood barrier and penetrate into the brain. Co-localization of CA and Nile red confirmed that micelles in lung and brain tissue were still intact. This study is the first to demonstrate that aerosolized PEGPLGA micelles are a promising carrier for both pulmonary and non-invasive systemic sustained release of labile drugs.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Micelas , Polímeros/administração & dosagem , Polímeros/farmacocinética , Animais , Disponibilidade Biológica , Avaliação Pré-Clínica de Medicamentos/métodos , Masculino , Ratos , Ratos WistarRESUMO
Use of soft drugs has resulted in mixed success with the applicability to chemotherapeutics yet being confirmed. We hypothesize that incorporation of a soft cytotoxic agent into polymeric micelles, which confer to stabilizing and sustained release effect, will improve and prolong the local antitumor efficacy, thus achieving the therapeutic potential of soft cytotoxic agents. We incorporated a model soft cytotoxic agent, zeylenone, into mPEG-PLGA micelles by solvent evaporation method. The drug loaded micelles were characterized in terms of drug encapsulation, dynamic size, zeta potential, drug stability and in vitro and in vivo release. The in vivo antitumor efficacy was evaluated in A549 tumor-bearing mice. Zeylenone-loaded micelles exhibited core-shell morphology with dynamic size of about 36 nm and offered efficient solubilizing and stabilizing effects. In vitro release and in vivo pharmacokinetic results indicated sustained release of zeylenone in micelles. In addition, local delivered zeylenone-loaded micelles showed improved and sustained antitumor effect in vivo, compared with intravenous administration or local delivery of free drug solution. This study demonstrates the feasibility of soft cytotoxic agent to achieve local antitumor efficacy after the drug was stabilized and sustained the release within polymeric micelles.