Mechanical and release behaviour of theophylline from matrix tablets containing psyllium powder in combination with grewia polysaccharides

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 188; p. 110809
• Main Authors: Nep, E.I., Kaur, N., Shaboun, S., Adebisi, A.O., Smith, A.M., Conway, B.R., Asare-Addo, K.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2020
• Subjects: buffers; compressibility; Grewia; Grewia polysaccharides; hardness; hydrochloric acid; Matrices; phosphates; porosity; powders; Psyllium gum; Release behaviour; strength (mechanics); Theophylline; Grewia polysaccharides; Matrices; Psyllium gum; Theophylline; Release behaviour
• ISSN: 0927-7765; 1873-4367; 1873-4367
• DOI: 10.1016/j.colsurfb.2020.110809

[Display omitted] •Softer compacts and burst release of theophylline from psyllium matrices.•Addition of GG and GDS imparts mechanical strength to psyllium matrices.•GG and GDS addition to psyllium eliminates burst drug release effect.•Synergistic effect of grewia and psyllium gives options in the formulation process. This study was aimed at investigating the effect of grewia polysaccharides on the mechanical and release properties of tablet matrices containing binary mixtures of the polysaccharide with psyllium. Two grades of grewia polysaccharides (GG and GDS) were extracted and binary mixtures of the polysaccharides with psyllium were formulated into tablet matrices containing theophylline as the model drug. The true, bulk and tapped densities, Carr’s compressibility index of the powders and binary composites were determined before tablet compression. Tablet properties (hardness, porosity, and drug release from the matrices) were investigated. The dissolution test was carried out in 0.1 M HCl (pH 1.2) and phosphate buffer (pH 6.8). The results show that GG and GDS produced tablets with good mechanical strength (108.33 N and 95.70 N, respectively) while psyllium produced softer tablets (7.13 N). The combination of psyllium and grewia polysaccharides in the matrices resulted in a significant increase in the mechanical strength of the matrices when compared to matrices containing psyllium alone as the matrix former. The results also showed that GG and GDS reduced the dissolution rate and effectively eliminated the burst release of theophylline from the psyllium matrices at both pHs. The matrices of GG or GDS and the binary mixtures conform to non-Fickian anomalous diffusion with n > 0.45. When overcoming the burst release of drug from matrices such as psyllium, grewia polysaccharides may provide an effective reduction and a more sustained drug release from such matrices.