Evaluation of Cedrela gum as a binder and bioadhesive component in ibuprofen tablet formulations

The compressional, mechanical and bioadhesive properties of tablet formulations incorporating a new gum obtained from the incised trunk of the Cedrela odorata tree were evaluated and compared with those containing hydroxypropylmethylcellulose (HPMC). Compressional properties were evaluated using Hausner's ratio, Carr's Index, the angle of repose, and Heckel, Kawakita and Gurnham plots. Ibuprofen tablets were prepared using the wet granulation method. Bioadhesive studies were carried out using the rotating cylinder method in either phosphate buffer pH 6.8 or 0.1 M hydrochloric acid media. The gum is a low viscosity polymer (48 cPs), and Fourier transform infrared spectroscopy revealed the presence of a hydroxyl group. Py and Pk values, which are measures of plasticity, showed the gum to be significantly (p<0.05) more plastic than HPMC, and plasticity increased with polymer concentration. All tablet formulations were non-friable (<1.0%), and the formulations containing the gum had a higher crushing strength (130.95 N) than those containing HPMC (117.85 N) at 2.0% w/w binder. Formulations incorporating the gum were non-disintegrating and had a significantly longer drug release time than those containing HPMC. At the highest binder concentration, Cedrela gum formulations adhered to incised pig ileum longer than those containing HPMC. Cedrela gum exhibited better compressive, flow and binding properties than HPMC and is suitable as a bioadhesive and for sustained release of drugs. Propriedades de compress o, mecanicas e de formula es de comprimidos bioadesivos, que incorporam nova goma de mascar obtidas a partir de incis o de tronco da árvore de Cedrela odorata, foram avaliadas e comparadas com aquelas contendo hidroxipropilmetilcelulose (HPMC). Propriedades de compress o foram avaliadas usando a raz o de Hausner, índice de Carr, angulo de repouso e os gráficos de Heckel, Kawakita e Gurnham. Prepararam-se comprimidos de ibuprofeno utilizando o método de granula o a úmido. Realizaram-se estudos de bioadesividade utilizando o método de cilindro rotativo em tamp o fosfato pH 6,8, ou meio ácido com 0,1 M de ácido clorídrico. A goma é um polímero de baixa viscosidade (48 cPs) e a espectroscopia no infravermelho por Transformada de Fourier (FTIR) revelou a presen a de um grupo hidroxila. Valores de Py e Pk, que s o medidas de plasticidade, mostraram que a goma é significativamente (p <0,05) mais plástica do que HPMC e que a plasticidade aumenta com a concentra o de polímero. Todas as formula es de comprimidos mostraram-se n o-friáveis (<1,0%) e aquelas contend