RESUMO
CONTEXT: Dry powder inhaler (DPI) formulations have been developed to deliver large amounts of drugs to the lungs. OBJECTIVE: Fine particles of a poorly water-soluble drug, the model drug ONO-2921, were prepared by the emulsion solvent diffusion (ESD) method for use in a DPI. METHODS: The effects of additives on the fine particle formation of ONO-2921 were estimated when droplets of an ethanolic drug solution were dispersed into aqueous media containing various additives. Subsequently, the suspensions were freeze-dried to create powdered samples to estimate the inhalation properties using a twin impinger and an Andersen cascade impactor. RESULTS: This simple ESD method produced submicron-sized ONO-2921 particles (approximately 600 nm) in combination with suitable additives. In addition, the freeze-dried powder produced using additives exhibited superior in vitro inhalation properties. Among these methods, the freeze-dried powder produced with 0.50% weight/volume one type of polyvinyl alcohol (PVA-205) displayed the most efficient features in the fine particle fraction (FPF). These results could be explained by the stabilization of the ONO-2921 suspension by PVA-205, indicating that PVA-205 acts as an aggregation inhibitor of fine particles. CONCLUSIONS: The ESD method, in combination with appropriate types and amounts of additives, may be useful for preparing a DPI suitable for delivering drugs directly to the lungs without the assistance of carrier particles.
Assuntos
Química Farmacêutica/métodos , Portadores de Fármacos/síntese química , Inaladores de Pó Seco/métodos , Emulsões/síntese química , Administração por Inalação , Difusão , Portadores de Fármacos/administração & dosagem , Emulsões/administração & dosagem , Tamanho da Partícula , Difração de Raios XRESUMO
Although the level of prostaglandin (PG) D(2) in cerebrospinal fluid (CSF) affects the action of D-type prostanoid receptors that promote physiological sleep, the regulatory system of PGD(2) clearance from the CSF is not fully understood. The purpose of this study was to investigate PGD(2) elimination from the CSF via the blood-CSF barrier (BCSFB). The in vivo PGD(2) elimination clearance from the CSF was 16-fold greater than that of inulin, which is considered to reflect CSF bulk flow. This process was inhibited by the simultaneous injection of unlabeled PGD(2). The characteristics of PGD(2) uptake by isolated choroid plexus were, at least partially, consistent with those of PG transporter (PGT) and organic anion transporter 3 (OAT3). Studies using an oocyte expression system showed that PGT and OAT3 were able to mediate PGD(2) transport with a Michaelis-Menten constant of 1.07 and 7.32 µM, respectively. Reverse transcription-polymerase chain reaction and immunohistochemical analyses revealed that PGT was localized on the brush-border membrane of the choroid plexus epithelial cells. These findings indicate that the system regulating the PGD(2) level in the CSF involves PGT- and OAT3-mediated PGD(2) uptake by the choroid plexus epithelial cells, acting as a pathway for PGD(2) clearance from the CSF via the BCSFB.
Assuntos
Barreira Hematoencefálica/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/líquido cefalorraquidiano , Transportadores de Ânions Orgânicos/líquido cefalorraquidiano , Prostaglandina D2/líquido cefalorraquidiano , Sono/fisiologia , Animais , Transporte Biológico , Plexo Corióideo/metabolismo , Cromatografia Líquida de Alta Pressão , Células Epiteliais/metabolismo , Feminino , Imuno-Histoquímica , Injeções Intraventriculares , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos , Oócitos/metabolismo , Transportadores de Ânions Orgânicos/sangue , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/sangue , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Prostaglandina D2/administração & dosagem , Prostaglandina D2/genética , Prostaglandina D2/farmacocinética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Distribuição Tecidual , Xenopus laevisRESUMO
To identify potent EP2/EP4 dual agonists with excellent subtype selectivity, a series of γ-lactam prostaglandin E analogs bearing a 16-phenyl ω-chain were synthesized and evaluated. Structural hybridization of 1 and 2, followed by more detailed chemical modification of the benzoic acid moiety, led us to the discovery of a 2-mercaptothiazole-4-carboxylic acid analog 3 as the optimal compound in the series. An isomer of this compound, the 2-mercaptothiazole-5-carboxylic acid analog 13, showed 34-fold and 13-fold less potent EP2 and EP4 receptor affinities, respectively. Structure activity relationship data from an in vitro mouse receptor binding assay are presented. Continued evaluation in an in vivo rat model of another 2-mercaptothiazole-4-carboxylic acid analog 17, optimized for sustained compound release from PLGA microspheres, demonstrated its effectiveness in a rat bone fracture-healing model following topical administration.
Assuntos
Prostaglandinas Sintéticas/química , Receptores de Prostaglandina E Subtipo EP2/agonistas , Receptores de Prostaglandina E Subtipo EP4/agonistas , Tiazolidinas/química , Administração Tópica , Animais , Células CHO , Cricetinae , Cricetulus , Avaliação Pré-Clínica de Medicamentos , Fraturas Ósseas/tratamento farmacológico , Isomerismo , Camundongos , Prostaglandinas Sintéticas/síntese química , Prostaglandinas Sintéticas/uso terapêutico , Ratos , Receptores de Prostaglandina E Subtipo EP2/genética , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Receptores de Prostaglandina E Subtipo EP4/genética , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Relação Estrutura-Atividade , Tiazolidinas/síntese química , Tiazolidinas/uso terapêuticoRESUMO
To identify topically effective EP4 agonists and EP2/EP4 dual agonists with excellent subtype selectivity, further optimization of the 16-phenyl ω-chain moiety of the γ-lactam 5-thia prostaglandin E analog and the 2-mercaptothiazole-4-carboxylic acid analog were undertaken. Rat in vivo evaluation of these newly identified compounds as their poly (lactide-co-glycolide) microsphere formulation, from which sustained release of the test compound is possible, led us to discover compounds that showed efficacy in a rat bone fracture healing model after its topical administration without serious influence on blood pressure and heart rate. A structure-activity relationship study is also presented.
Assuntos
Lactamas/síntese química , Lactamas/farmacologia , Prostaglandinas E Sintéticas/síntese química , Prostaglandinas E Sintéticas/farmacologia , Receptores de Prostaglandina E Subtipo EP2/agonistas , Receptores de Prostaglandina E Subtipo EP4/agonistas , Administração Tópica , Animais , Pressão Sanguínea/efeitos dos fármacos , Células CHO , Cricetinae , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Dinoprostona/química , Avaliação Pré-Clínica de Medicamentos/métodos , Consolidação da Fratura/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Lactamas/administração & dosagem , Masculino , Camundongos , Microesferas , Estrutura Molecular , Poliglactina 910/administração & dosagem , Poliglactina 910/química , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tiazolidinas/químicaRESUMO
Pranlukast hydrate was demonstrated in a human site-of-absorption study to have extremely poor absorption properties in the lower gastrointestinal tract. The ratios of AUC0-24 in the distal small bowel and colon compared to stomach delivery were approximately 1/7 and 1/70, respectively. As a consequence, a gastroretentive double-layered tablet formulation (gastric swelling system; GSS), consisting of a swelling layer and a drug release layer, was developed for once-daily dosing. To study the gastric retention of the optimized GSS, an in vivo gamma scintigraphic study was carried out in nine healthy volunteers. The transit profiles demonstrated that the GSS was retained in the stomach for more than 10h. The plasma profile was prolonged, especially following administration after an evening meal. The human data validated the design concept and suggest that GSS could be a promising approach for the development of sustained-release formulation for drugs with a limited absorption window in the upper small bowel.
Assuntos
Antiasmáticos/farmacocinética , Cromonas/farmacocinética , Sistemas de Liberação de Medicamentos , Mucosa Gástrica/metabolismo , Adolescente , Adulto , Antiasmáticos/sangue , Antiasmáticos/química , Cromonas/sangue , Cromonas/química , Estudos Cross-Over , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Trânsito Gastrointestinal , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Naturally occurring prostaglandin E2 (PGE2) plays a role in inflammatory responses through eicosanoid signaling pathways. PGE2 is impermeable to cell membranes at physiological pH and needs solute carrier across the membranes; however, it remains unclear how intercellular concentrations of PGE2 are regulated under the condition of inflammation. We aimed to clarify a role of organic anion-transporting polypeptide 2A1 (OATP2A1/SLCO2A1), also known as prostaglandin transporter (PGT), in PGE2 release from cells. Human bronchial epithelial BEAS-2B cells were treated with lipopolysaccharide (LPS), and PGT inhibitors were tested to evaluate contribution of PGT to PGE2 release by assessing its extracellular concentration and characterizing PGT-mediated PGE2 efflux in Xenopus laevis oocytes. As a result, LPS elevated mRNA expression of a pro-inflammatory cytokine IL6 and extracellular concentration of PGE2 in human bronchial epithelial BEAS-2B cells. PGT inhibitors tested (e.g. bromocresol green (BCG), bromosulfophthalein (BSP), and PGB1) significantly inhibited efflux of PGE2 from oocytes expressing PGT. Similarly, the amount of released PGE2 from the BEAS-2B cells decreased in the presence of BCG and BSP by 45 and 44% respectively while TGBz increased the concentration by 71%, suggesting that PGT mediates the release. In conclusion, these results imply a role of PGT in regulating intra- and extracellular concentrations of PGE2 in response to cells under inflammatory conditions.
Assuntos
Brônquios/metabolismo , Dinoprostona/metabolismo , Células Epiteliais/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Transdução de Sinais/fisiologia , Células 3T3-L1 , Animais , Brônquios/citologia , Brônquios/efeitos dos fármacos , Linhagem Celular , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Transportadores de Ânions Orgânicos/genética , Transdução de Sinais/efeitos dos fármacos , Xenopus laevisRESUMO
INTRODUCTION: Osteoarthritis (OA) is a common cause of disability in older adults. We have previously reported that an agonist for subtypes EP2 of the prostaglandin E2 receptor (an EP2 agonist) promotes the regeneration of chondral and osteochondral defects. The purpose of the current study is to analyze the effect of this agonist on articular cartilage in a model of traumatic degeneration. METHODS: The model of traumatic degeneration was established through transection of the anterior cruciate ligament and partial resection of the medial meniscus of the rabbits. Rabbits were divided into 5 groups; G-S (sham operation), G-C (no further treatment), G-0, G-80, and G-400 (single intra-articular administration of gelatin hydrogel containing 0, 80, and 400 µg of the specific EP2 agonist, ONO-8815Ly, respectively). Degeneration of the articular cartilage was evaluated at 2 or 12 weeks after the operation. RESULTS: ONO-8815Ly prevented cartilage degeneration at 2 weeks, which was associated with the inhibition of matrix metalloproteinase-13 (MMP-13) expression. The effect of ONO-8815Ly failed to last, and no effects were observed at 12 weeks after the operation. CONCLUSIONS: Stimulation of prostaglandin E2 (PGE2) via EP2 prevents degeneration of the articular cartilage during the early stages. With a system to deliver it long term, the EP2 agonist could be a new therapeutic tool for OA.
Assuntos
Cartilagem Articular/lesões , Cartilagem Articular/patologia , Traumatismos do Joelho/patologia , Traumatismos do Joelho/prevenção & controle , Prostaglandinas/administração & dosagem , Receptores de Prostaglandina E Subtipo EP2/agonistas , Animais , Cartilagem Articular/efeitos dos fármacos , Células Cultivadas , Feminino , Microesferas , Prostaglandinas/química , Coelhos , Distribuição Aleatória , Receptores de Prostaglandina E Subtipo EP2/fisiologiaRESUMO
We studied the effects of dextran, dextrin, and disintegrants on the chemical stability of Opalmon tablets containing Limaprost-alfadex (Limaprost/alpha-cyclodextrin complex) and found that the addition of dextran or dextrin significantly improved the chemical stability of Opalmon tablets under high humidity, compared to lactose. We also examined how dextran stabilizes Limaprost in Opalmon tablets and studied the formulation of Opalmon tablets in order to achieve higher chemical stability, rapid dissolution and reduced stickiness. The results suggested that dextran increases stabilization after moisture adsorption by decreasing the dissociation of Limaprost-alfadex to the free drug and alpha-cyclodextrin in the dextran matrix, when compared with the lactose matrix. The stickiness of Opalmon tablets containing dextran and dextrin was negligible when dextran and dextrin amounted to less than 20% of the formulation. By selecting a proper disintegrant, we obtained Opalmon tablets with higher chemical stability and rapid dissolution properties.