Influência do processo de secagem e condição de armazenamento de extratos secos de Bauhinia forficata e Passiflora alata sobre seu perfil de dissolução / Influence of the drying process and storage condition on the dissolution behavior of dried extracts of Bauhinia forficata and Passiflora alata

No Brasil, os produtos fitoterápicos são considerados medicamentos, sendo necessário o estabelecimento de estudos que assegurem a manutenção dos requisitos de qualidade durante o processamento e o armazenamento. Testes de dissolução podem ser empregados para se estimar a biodisponibilidade de um fármaco, sendo uma análise rotineira no desenvolvimento e controle de qualidade de medicamentos alopáticos. A determinação do perfil de dissolução de fitoterápicos também pode ser um importante critério para avaliação da sua qualidade lote-a-lote, bem como para os estudos de desenvolvimento e de estabilidade. O objetivo deste trabalho foi investigar a influência dos métodos de secagem e da condição de armazenagem sobre os perfis de dissolução dos flavonoides totais de extratos secos de duas plantas medicinais bastante difundidas no Brasil, a Bauhinia forficata e a Passiflora alata. Os extratos secos foram produzidos pelo processo de secagem em leito de jorro e em spray drying, sendo submetidos a condições de armazenagem aceleradas (temperatura de 40 ± 2ºC e umidade relativa de 75 ± 5%, por um período de 90 dias). Os perfis de dissolução foram obtidos para amostras de extratos secos antes e após o período de armazenamento. O teor de flavonoides totais foi quantificado por espectrofotometria. Os extratos secos de B. forficata e P. alata apresentaram adequada liberação de flavonoides nos ensaios de dissolução. Os extratos secos de Passiflora alata apresentaram completa dissolução dos flavonoides, 92% e 98% dos teores originais após 60 minutos de ensaio, respectivamente para o extrato seco em leito de jorro e em spray drying.

In Brazil, most of the herbal medicinal products are considered as medicine. Therefore, it is necessary the establishment of tests to guarantee the maintenance of quality requirements during their processing and storage. The dissolution test is used to estimate the bioavailability of drugs and is routinely used in the development and the quality control of allopathic medicines. The determination of the dissolution profile of herbal products can also be an important criterion for assessing the batch-to-batch quality as well as for studies of product development and stability. This work aimed to investigate the dissolution profiles of dried extracts of two medicinal plants widely used in Brazil, the Bauhinia forficata and Passiflora alata, by assessing the effect of the drying methods and storage condition on the release of the total flavonoid contents. Spouted bed and spray drying were the processes used for the production of the dried extracts. The products were subjected to accelerated storage conditions (temperature of 40 ± 2ºC and relative humidity of 75 ± 5%, for 90 days). The dissolution profiles of the dried extracts, before and after storage, were determined. The concentration of total flavonoids was quantified by spectrophotometry. Adequate dissolution profiles of flavonoids from B. forficata and P. alata were obtained for all the dried extracts produced. The dried extracts of Passiflora alata showed the complete dissolution of flavonoids in the dissolution media investigated, respectively 92% and 98% of flavonoids present in the dried extracts in spouted bed and spray drying after 60 minutes of the dissolution testing.

Assessment of antioxidant activity of spray dried extracts of Psidium guajava leaves by DPPH and chemiluminescence inhibition in human neutrophils.

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and ß -cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH(•) method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells.

In vitro dissolution studies of sodium diclofenac granules coated with Eudragit L-30D-55 by fluidized-bed system.

The objective of this work was to study the dissolution process of sodium diclofenac granules coated with a polymeric suspension of Eudragit L-30D-55 by fluidized bed. Methacrylic acid-methylmetacrylate copolymer, also known as Eudragit, has been used as a pH sensitive coating material to protect drug substances prior to delivery to the human intestines. The sodium diclofenac granules were prepared by wet granulation technology using microcrystalline cellulose (MICROCEL), sodium diclofenac, and polivinilpirrolidone K-30. The granules coating operation was carried out in a fluidized bed with top spraying by a double-fluid nozzle. The dissolutions studies of the coated granules were performed in triplicate in a dissolution test station according to USP XXIII (1995) "in vitro testing requirements" Method A (paddle method, rotation of 100 RPM and temperature fixed at 37 degrees C). The dissolution mediums were 0.1N HCl solution and a pH 6.8 phosphate buffer solution, following the pH change dissolution procedure specified in USP for enteric-coated articles: 2 h of exposure to 750 mL of 0.1N HCl followed by testing in 1000 mL of pH 6.8 phosphate buffer, the pH being adjusted with 250 mL of 0.2 M tribasic sodium phosphate solution. The released amount of sodium diclofenac was periodically determined by UV spectrophotometry at wavelength of 276 nm, using a spectrophotometer UV-VIS HP 8453. The coated product showed gastric resistance properties confirming the feasibility of the fluidized bed for applying enteric coating in granules and pharmaceutical powders.