Tri Susanti, Syahnur Haqiqoh, Pratiwi Pudjiastuti, Siti Wafiroh, Esti Hendradi, Oktavia Eka Puspita, Nashriq Jailani
This study aims to enhance the mechanical properties, disintegration, and dissolution rates of crosslinked carrageenan (CRG) capsule shells by shortening the long chains of CRG through a hydrolysis reaction with citric acid (CA). The hydrolysis of CRG was carried out using varying concentrations of CA, resulting in hydrolyzed CRG (HCRG). This was followed by cross-linking with xanthan gum (XG) and the addition of sorbitol (SOR) as a plasticizer. The results indicated that the optimal swelling capacity of HCRG-XG/SOR hard-shell capsules occurred at a CA concentration of 0.5%, achieving a maximum swelling rate of 445.39% after 15 min. Additionally, the best capsule hardness was also measured at this CA concentration, reaching a hardness level of 480.157 g (F = 4.67 N). FTIR analysis demonstrated that the presence of the acid group from CA altered the composition of the CRG chains. Furthermore, SEM-EDX mapping analysis revealed that the surface morphology of the synthesized capsules exhibited a relatively smooth texture with a limited number and size of pores, resulting in good capsule stability for drug delivery. The in vitro disintegration and dissolution rates of the HCRG-XG/SOR capsules were observed to be the fastest and highest at pH 1.2, respectively. The disintegration time was recorded at 20 min and 46 s, while the dissolution test indicated a drug release of 78.08% after 5 min and 100% after 120 min. The drug delivery kinetics of HCRG-XG/SOR followed the Ritger-Peppas model, indicating a complex release mechanism that involved swelling, diffusion, erosion, and capsule disintegration. Copyright © 2025 The Authors.
Halal Research Center, Airlangga University, Surabaya, 60286, Indonesia; Departement of Chemistry, Faculty of Science dan Technology, Airlangga University, Surabaya, 60115, Indonesia; Department of Pharmaceutical Sciences, Faculty of Pharmacy, Airlangga University, Surabaya, 60115, Indonesia; Departement Pharmacy, Faculty of Medicine, Brawijaya University, Malang, 65145, Indonesia; Department of Bioprocess & Polymer Engineering, Faculty of Chemical & Energy Engineering, Universiti Teknologi Malaysia, Johor, Skudai, 81310, Malaysia
