H.N. Imtihani, N.I. Azkiya, Y. Nailufa
Biochitosan derived from marine biomass has attracted wide interest in pharmaceutical and biomedical applications due to its biocompatibility and functional amino groups. This study aimed to isolate and characterise chitosan from mangrove crab (Scylla paramamosain) shell waste and to evaluate the physicochemical differences between high molecular weight chitosan (HMWC) and low molecular weight chitosan (LMWC) for their potential use in cocrystal formulations. Chitosan was isolated through demineralisation, deproteinization, deacetylation, and decalcification, followed by depolymerisation to obtain LMWC. Physicochemical evaluations included moisture content, ash value, degree of deacetylation (DD), ninhydrin test, SEM morphology, SEM-EDX elemental analysis, FTIR spectroscopy, XRD, and Gel Permeation Chromatography (GPC). The results showed that LMWC exhibited superior quality, with lower moisture (3.09%) and ash content (7.41%), and the highest DD (77.76%) compared to HMWC. SEM images confirmed that LMWC had a finer and more porous morphology, while SEM-EDX revealed the dominance of carbon and oxygen with undetected nitrogen due to instrumental limitations. FTIR confirmed the presence of –NH₂ and – OH groups, and XRD patterns indicated that LMWC exhibited crystallinity more consistent with standard chitosan than HMWC. GPC further demonstrated a significant reduction in molecular weight from 73,000 Da (HMWC) to 19,000 Da (LMWC), improving solubility and reactivity. Collectively, these findings indicate that LMWC more closely resembles commercial chitosan in structural and functional properties, making it more suitable for pharmaceutical cocrystal formulation. © 2026, Rasayan Journal of Chemistry, c/o Dr. Pratima Sharma. All rights reserved.
Department of Technology Pharmacy, University of Hang Tuah, Surabaya, 60111, Indonesia; Department of Chemical Engineering, Politeknik Negeri Malang, Malang, 65141, Indonesia