A novel hydrogel plug ofSterculia urensfor pulsatile delivery:in vitroandin vivoevaluation

Abstract

The objective of this study was to investigate a novel hydrogel plug using isolated root mucilage of Sterculia urens to obtain a desired lag time for an oral chronotherapeutic colon-specific pulsatile drug delivery of indomethacin. Pulsatile drug delivery was developed using chemically treated hard gelatin capsule bodies filled with eudragit multiparticulates of indomethacin, and sealed with different hydrogel plugs (root mucilage of S. urens, xanthan gum, guar gum, HPMC K4M and combination of maltodextrin with guar gum). Indomethacin multiparticulates were prepared using extrusion spheronization, spray drying and solvent evaporation techniques with Eudragit® L-100 and S-100 (1:2) by varying drug-to-polymer ratio. After oral administration, the water-soluble cap of capsule dissolved in the intestinal fluid and the hydrogel plug swells. After a controlled time, the swollen plug subsequently ejected from the dosage form, releases the contents of the capsule. The formulation factors affecting the drug release were concentration and types of hydrogel plug used. In vivo gamma scintigraphy study in healthy rabbits proved the capability of the system to release drug in lower parts of the gastrointestinal tract after a programmed lag time. This study demonstrates that the indomethacin multiparticulates could be successfully colon-targeted by the design of time and pH-dependent modified chronopharmaceutical formulation. In conclusion, the investigated novel hydrogel plug could be a valuable tool for achieving desired lag time.

Sterculia and Brachychiton: a comprehensive overview on their ethnopharmacology, biological activities, phytochemistry and the role of their gummy exudates in drug delivery

“…The study was conducted both in vitro and in vivo using healthy rabbits, and the formulation ensures pulsatile drug delivery of the drug in the colon. [117] The gum enhanced the repair of gastric mucosa, so it was used in the formulation of gastroretentive drug-delivery system containing pantoprazole which is used for the treatment of peptic ulcer. [118] A hydrogel for the treatment of diarrhoea was formulated using S. urens gum and ornidazole; both of them proved to possess antidiarrhoeal properties.…”