ABSTRACT
Nanocrystal formulations have been explored to deliver poorly water-soluble drug molecules. Despite various studies of nanocrystal formulation and delivery, much more understanding needs to be gained into absorption mechanisms and kinetics of drug nanocrystals at various levels, ranging from cells to tissues and to the whole body. In this study, nanocrystals of tetrakis (4-hydroxyphenyl) ethylene (THPE) with an aggregation-induced emission (AIE) property was used as a model to explore intracellular absorption mechanism and dissolution kinetics of nanocrystals. Cellular uptake studies were conducted with KB cells and characterized by confocal microscopy, flow cytometry, and quantitative analyses. The results suggested that THPE nanocrystals could be taken up by KB cells directly, as well as in the form of dissolved molecules. The cellular uptake was found to be concentration- and time-dependent. In addition, the intracellular THPE also could be exocytosed from cells in forms of dissolved molecules and nanocrystals. Kinetic modeling was conducted to further understand the cellular mechanism of THPE nanocrystals based on first-order ordinary differential equations (ODEs). By fitting the kinetic model against experimental measurements, it was found that the initial nanocrystal concentration had a great influence on the dynamic process of dissolution, cellular uptake, and exocytosis of THPE nanocrystals. As the nanocrystal concentration increased in the culture media, dissolution of endocytosed nanocrystals became enhanced, subsequently driving the efflux of THPE molecules from cells.
ABSTRACT
Objective: Establishing the model of cell bioelectrical sensing effect of Compound Danshen Tablets to study its dissolution kinetics. Methods: By means of real-time cell-based assay, the in vitro dissolution of Compound Danshen Tablets can be investigated, and then the dissolution kinetics model can also be established. In addition, the result was compared and verified by UV-Vis. Results: The cell line with specific dependence on Compound Danshen Tablets was screened by CCK-8 experiment and RTCA experiment. The dissolution kinetics model of Compound Danshen Tablets based on RTCA technology was established, and the best fitting model was obtained: Weibull model ln{ln[1/(1-Q)] =1.071 4 lnt-3.736 7; Establish a dissolution kinetic model of Compound Danshen Tablets based on UV spectrophotometry to obtain the best fitting model, Weibull model ln{ln[1/(1-Q)]}=1.080 4 lnt-3.723 4; Comparing the two Weibull models, the RTCA fitted model worked better. Conclusion: The application of RTCA in the dissolution kinetics of traditional Chinese medicine compound solid preparations is feasible, Which provides new ideas for traditional Chinese medicines and the quality evaluation of traditional Chinese medicine compunds.
ABSTRACT
En las décadas pasadas se incrementó los casos de malaria en los países de la cuenca amazónica, inclu-yendo la aparición de P. falciparum y la resistencia a los medicamentos de primera línea; Cloroquina y Sulfadoxina / Pirimetamina, adicionalmente en estudios recientes se reportaron deficiencias en la calidad de los medicamentos antimalaricos43. Por lo que Perú cambió su esquema de tratamiento para P. falcipa-rum no complicada: con Mefloquina más Artesunato en la selva y Sulfadoxina / Pirimetamina en la costa norte. En el esquema de tratamiento de Perú, se utiliza un medicamento genérico nacional (multifuente) que no ha demostrado ser intercambiable con el medicamento original, debido a que la regulación actual no ha implementado este requisito; aunque en la Ley 29459, ya se señale como parte de los requisitos del Registro Sanitario y que se espere entre en vigencia gradualmente. Objetivo: comparar las disponibilida-des in vitro de las tabletas de Artesunato usadas por la estrategia sanitaria de malaria en Perú, con las tabletas de Artesunato fabricadas en empresas precalificadas por la Organización Mundial de la Salud (OMS) en Brasil y Ghana. Metodología: para los ensayos de control de calidad y pruebas de cinética de disolución se utilizó la Farmacopea Non Standard de Los Estados Unidos, las guías de FDA y OMS...
Malaria cases have increased in the countries of the Amazon basin in the past decades, including the ap-pearance of P. falciparum and resistance to first-line drugs; Chloroquine and Sulfadoxine / Pyrimethamine. In recent studies were reported deficiencies in the quality of antimalarial drugs, because of that Peru changed the treatment scheme for uncomplicated P. falciparum, and begin to use Mefloquine plus Arte-sunate for Amazon Area and Sulfadoxine / Pyrimethamine on the North coast. In Peruvian treatment scheme, is used a national generic drug (multisource), which one did not demonstrate to be interchangea-ble with the innovator, because, this is not yet a requirement to get the Sanitary Register, according to Law 29459, and hopefully it will be implemented gradually. Objective: compare the in vitro availability of Artesunate tablets used by the health strategy against malaria in Peru, with Artesunate tablets manufac-tured by WHO prequalified manufactures from Brazil and Ghana. Methodology: testing and dissolution kinetics tests were performed with Non Standard Pharmacopoeia of the United States, FDA and WHO guidelines...
Subject(s)
Humans , Antimalarials , Artemisinins/therapeutic use , Malaria , PharmacokineticsABSTRACT
Meloxicam is a broadly used drug in the therapeutics for the osteoarthritis and rheumatoid arthritis treatments in adults, and it is available in the Brazilian market, as tablet and capsule pharmaceutical forms. The present work aimed to establish conditions for accomplishment of the dissolution test of 15 mg meloxicam tablets (A and B test products), compared with the reference product, since there is no monograph about dissolution assays for meloxicam in official summaries. To optimize the conditions several parameters were tested and, according to obtained results, the use of pH 7.5 phosphate buffer (900mL, at 37 ± 0.5ºC) as dissolution medium, paddle method (apparatus 2), stirring speed of the dissolution medium at 100 rpm and collect time of 60 minutes were considered satisfactory. The samples were quantified by UV spectrophotometric method at 362 nm. The products presented kinetics of first-order. Dissolution efficiency values were of 83.25, 83.73 and 88.10 percent for the A, B and reference products, respectively. Factors f1 and f2 were calculated and similarity of the tested medicines was demonstrated. The dissolution test was validated presenting selectivity, linearity, precision and accuracy within of the acceptance criteria.
O meloxicam é fármaco amplamente utilizado na terapêutica para o tratamento de osteoartrite e artrite reumatóide em adultos, e encontra-se disponível no mercado brasileiro, sob as formas farmacêuticas comprimido e cápsula. O presente trabalho objetivou estabelecer condições para realização do teste de dissolução de meloxicam 15 mg na forma farmacêutica comprimido (medicamentos-teste A e B), comparado com o medicamento de referência, visto que não há monografia para o ensaio de dissolução com meloxicam em compêndios oficiais. Para otimização das condições, diversos parâmetros foram testados e de acordo com os resultados obtidos, a utilização de tampão fosfato pH 7,5 (900mL, a 37 ± 0,5 ºC) como meio de dissolução, aparato 2 (pá), velocidade de agitação do meio de dissolução de 100 rpm e tempo de coleta em 60 minutos, foram considerados satisfatórios. As amostras foram quantificadas por espectrofotometria na região do ultravioleta, a 362 nm. Os produtos apresentaram cinética de primeira ordem. Para a eficiência de dissolução encontraram-se valores de 83,25, 83,73 e 88,10 por cento para os medicamentos-teste A e B e referência, respectivamente. Os fatores f1 e f2 foram calculados, demonstrando haver similaridade entre os medicamentos avaliados. O ensaio de dissolução foi validado apresentando seletividade, linearidade, precisão e exatidão dentro dos critérios de aceitação.
Subject(s)
Humans , Adult , Antirheumatic Agents , Tablets/pharmacokinetics , Dissolution/methods , Spectrophotometry , Osteoarthritis , Rheumatic DiseasesABSTRACT
A Síndrome da Imunodeficiência adquirida (AIDS) é uma doença de amplo espectro de manifestações, sendo razão de preocupação para qualquer autoridade sanitária. A terapêutica da AIDS é complexa sendo utilizados vários medicamentos, diversas vezes ao dia. Deste modo, objetivou-se o desenvolvimento de formas farmacêuticas sólidas como comprimidos tamponados mastigáveis (CTM), comprimidos com revestimento gastro-resistentes (CRGR) e pellets (PEL) para a veiculação de didanosina (ddl). Seis especialidades farmacêuticas na forma de CTM forma estudadas quanto ao perfil de dissolução, pH do meio e capacidade neutralizante ácida (CNA). Formulações teste de CTM foram propostas visando obter CNAs e perfis de dissolução adequados. Também foram testadas formulações de comprimidos e de pellets para posterior revestimento com filme gastro-resistente derivado do ácido metacrílico. Os ensaios de dissolução das amostras de CTM revelaram diferenças nas características de liberação do fármaco. Também foram observadas diferenças relacionadas a CNA. As formulações de CTM propostas apresentaram, na maioria dos casos, adequados perfis de dissolução e CNA. As formulações CRGR que receberam revestimento gastro-resistente apresentaram perfis de dissolução de ddl adequados, entretanto os comprimidos testados intumesceram em meio ácido, indicando descontinuidade do filme polimérico sobre os comprimidos. Testes para a produção de pellets veiculando ddl mostraram-se adequados quanto à morfologia e dissolução do fármaco, o mesmo sendo observado após o revestimento com filme gastro-resistente
The Acquired Immune Deficiency Syndrome (AIDS) is a disease that manifests itself in a myriad of ways. Because of this, the condition has been subject of concern to all sanitary authorities. The treatment of AIDS is complex and many types of medicine are used, many times a day. The objective of the present study was to develop solid pharmaceutical dosage forms such as buffered chewable tablets (CTM), gastro-resistant coating tablets (CRGR) and pellets (PEL) for the loading of didanosine (ddl). Six pharmaceutical specialties in the form of CTM were studied so as to identify the profile of the dissolution, the pH of the environment, and the neutralizing acid capacity (CNA). The use of CTM tests formulations was proposed with the objective of obtaining adequate CNA and dissolution profiles. Different compositions of tablets and pellets were tested for a later addition of gastro-resistant film derived from the methacrylic acid. The experiments on the dissolution of the sample of CTM showed differences in the characteristic of the release of the substance. Differences related to the CNA were also observed. The formulations of the CTM proposed showed to have, in the most number of the cases, both adequate dissolution behavior and CNA. The formulations of the CRGR that had received the gastro-resistant coating showed adequate profile of ddl dissolution; the tested tablets, however, swelled in the acid environment, therefore indicating a lack of continuity of the polymeric film over the tablets. The tests for the production of pellets showed adequate results as to its morphology and dissolution of ddl. The same was observed after coating the pellets with gastro-resistant film.