Oxidised cellulose beads (anionic groups 0.1–1.85 mmol g−1) were loaded with ranitidine HCl. Polymorphic form and crystallinity of the drug was assessed by calorimetric and spectrometric techniques. Release profiles were obtained at physiological conditions and fitted to suitable mathematical models to gain an understanding on release mechanism. Solid‐state analysis showed that the drug was solidified in amorphous form. The amount of drug was uniform and increased with charge of the beads upto loading degree of 25.8%. Release profiles fitted well to the Baker‐Lonsdale’s model for non‐swelling system indicating open structure for freely soluble drug. The release was pH independent, providing fast release already at pH 1.2 in simulated gastrointestinal track.

Jani Trygg Emrah Yildir Ruzica Kolakovic Niklas Sandler Pedro Fardim
Macromolecular Materials and Engineering, 2014 https://doi.org/10.1002/mame.201400175