Preparation of Novel Hard Capsule Using Water-Soluble Polysaccharides and Cellulose Nanocrystals for Drug Delivery

Purpose To synthesize water-soluble polysaccharides and incorporate cellulose nanocrystals into hard capsule shells. Methods Water-soluble polysaccharides were extracted from 60 g of powder E. prolifera green algae and soaked for 3 h at 60 degrees C in 95% EtOH (in a 1:10). Enteromorpha prolifera green seaweed was chosen as the cellulose source, which had previously been bleached. A standard method of acid hydrolysis was used to make cellulose nanocrystals (CNCs). The extracted cellulose was dispersed in a 45%, 50% and 60% (w/w) H2SO4 solution (ratio of 1:10) for 45 min with constant stirring at 45 degrees C. Polysaccharide nanocomposite films were created using solution casting and evaporation techniques. Hard capsules were made by dipping a stainless-steel mould into polysaccharide solutions (cylindrical, 6 mm and 6.20 mm) and drying it at 40 degrees C for 3 h. Results CNC-formatted polysaccharide films exhibited 95% transparency and good mechanical, thermal, swelling and long-term viscosity measurements. It was demonstrated using FTIR, SEM, UV-vis spectroscopy and rheological behaviour analysis. Polysaccharide hard capsules were successfully prepared without air bubbles and with a disintegration time of about 4-5 min. An experiment revealed that 80% of the salicylic acid was released in 45-50 min. Drug release did not differ significantly between commercial gelatin and polysaccharide hard capsules. Conclusion Natural water-soluble polysaccharides have been used successfully as hard capsule materials.