Amorphous nanodrugs prepared by complexation with polysaccharides: Carrageenan versus dextran sulfate

Mitigating the adverse effect of spray drying on the supersaturation generation capability of amorphous nanopharmaceutical powders

“…The CIP solution was added slowly to the dextran sulfate solution under gentle stirring after which the mixture was let sit for 3 h. The amorphous CIP nanoparticles produced was recovered by centrifugation at 13,000×g for 5 min, followed by three cycles of washing before they were resuspended in deionized water. Physical characterizations of the amorphous CIP nanoparticles (i.e., size, shape, zeta potential, drug loading) were presented in Cheow, Kiew, and Hadinoto [15]; thus, they were not repeated here.…”

“…The amorphous CIP nanoparticles were prepared by self-assembly electrostatic complexation between ionized CIP molecules and oppositely charged polysaccharides as described in Cheow, Kiew, and Hadinoto [15]. Briefly, 10 mg CIP was dissolved in 1 mL 0.2% (v/v) aqueous acetic acid solution, while 4.5 mg dextran sulfate was dissolved in 1 mL deionized water containing 2.0 mg Pluronic F68.…”

“…The amorphous NP powders, which were made up of microscale aggregated nanoparticles, were found to be unable to generate the "spring and parachute" supersaturation profile. This was believed due to poor disassociation of the nanoparticle aggregates upon dissolution [13][14][15], which resulted in reduced surface areas available for dissolution, hence a slow dissolution velocity. The slow dissolution velocity in turn increased the crystallization propensity of the remaining solid phase undergoing dissolution, thus significantly lower supersaturation levels were generated after drying.…”

“…The supersaturation generation capability of the amorphous NP, however, has been demonstrated in several studies to be greatly diminished upon drying [13][14][15], which is a mandatory step in the oral solid dosage form preparation of any pharmaceuticals. The amorphous NP powders, which were made up of microscale aggregated nanoparticles, were found to be unable to generate the "spring and parachute" supersaturation profile.…”

Liquigroud technique: a new concept for enhancing dissolution rate of glibenclamide by combination of liquisolid and co-grinding technologies

“…7 Chemical modifications consist of pH change, 8 use of buffer, 9 derivatization, and salt formation. 10 Physical modifications include particle size reduction, 11 crystal engineering, 12 cryogenic techniques, 13 complex formation-based techniques, 14 drug dispersion in carriers, 15 and liquisolid techniques. 16-18 Regarding the dissolution enhancement of glibenclamide, some methods such as solid dispersion method, 6 co-administration of water-soluble polymers like HPMC 19 using self-microemulsifying drug delivery system, 20 and complexation with cyclodextrins 21 have been employed in recent years.…”