Preparation and ex vivo investigation of an injectable microparticulate formulation for gastrointestinal mucosa polyp resection Moles Aranda, Cristina Pérez González, Noelia Calpena-Campmany, Ana Martín Villena, María José Otero-Espinar, Francisco Javier Severino, Patricia Souto, Eliana B. Morales-Molina, José Antonio Clares Naveros, Beatriz Endoscopic submucosal dissection (ESD) Endoscopic submucosal resection (ESR) Injectable polymeric solution The authors acknowledge the local Regional Government of Andalusia (Junta de Andalucía), Spain [grant number PIN-0479-2016] and the Andalusian Foundation of Hospital Pharmacy, Spain‘ [grant number 2022]. Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection (EMR) are non-invasive endoscopic techniques. They allow an early excised gastrointestinal (GI) mucosal precancerous lessions. For their application is necessary use of a submucosal injection that lift area to excise. The main objective of this study was the preparation of microparticulate-based fluid for injection in the GI submucosa. Alginate microparticles (MPs) were developed by the solvent displacement technique and characterized by particle size, surface electrical properties, swelling, degradation, rheology, adhesion and leakage, syringeablity and stability. Furthermore, their potential to form a submucosal cushion was assayed in porcine stomach mucosa and porcine colon mucosa. Results showed MPs sizes below 160 μm, negative surface charge around -50 mV at pH=6, high rates of swelling and good adhesion. The microparticulate-based fluid exhibited pseudoplastic behavior following the Ostwald-de Waele rheological model. A brief force is sufficient for its injection through a syringe. Finally, formulations were able to provide a submucosa elevation of 1.70 cm for more than 90 min and 120 min in the porcine stomach and colon, respectively. 2025-09-17T07:16:54Z 2025-09-17T07:16:54Z 2022 journal article Published version: Cristina Moles-Aranda et al. Preparation and ex vivo investigation of an injectable microparticulate formulation for gastrointestinal mucosa polyp resection, European Journal of Pharmaceutics and Biopharmaceutics, Volume 178, 2022, Pages 25-34. https://doi.org/10.1016/j.ejpb.2022.07.012 https://hdl.handle.net/10481/106361 10.1016/j.ejpb.2022.07.012 eng open access Elsevier