Alginate graft copolymers and alginate–co-excipient physical mixture in oral drug delivery

Abstract

Objectives Use of alginate graft copolymers in oral drug delivery reduces dosage form manufacture complexity with reference to mixing or coating processes. It is deemed to give constant or approximately steady weight ratio of alginate to covalently attached co-excipient in copolymers, thereby leading to controllable matrix processing and drug release. This review describes various grafting approaches and their outcome on oral drug release behaviour of alginate graft copolymeric matrices. It examines drug release modulation mechanism of alginate graft copolymers against that of co-excipients in non-grafted formulations. Key findings Drug release from alginate matrices can be modulated through using either co-excipients or graft copolymers via changing their swelling, erosion, hydrophobicity/ hydrophilicity, porosity and/or drug adsorption capacity. However, it is not known if the drug delivery performance of formulations prepared using alginate graft copolymers is superior to those incorporating graft-equivalent co-excipient physically in a dosage form without grafting but at the corresponding graft weight, owing to limited studies being available. Conclusions The value of alginate graft copolymers as the potential alternative to alginate-co-excipient physical mixture in oral drug delivery cannot be entirely defined by past and present research. Such an issue is complicated by the lack of green chemistry graft copolymer synthesis approach, high grafting process cost, complications and hazards, and the formed graft copolymers having unknown toxicity. Future research will need to address these matters to achieve a widespread commercialization and industrial application of alginate graft copolymers in oral drug delivery

Cytotoxicity and Oxidative Stress Evaluation of Alginate/Cockle Shell Powder Nanobiocomposite Bone Scaffold on Osteoblast

“…The fabrication of this nanobiocomposite scaffold is achieved with the use of alginate, a naturally occurring polymer that provides the underlying matrix for the scaffold. Alginate from the brown algae is a polysaccharide that dissolves in water and is generally regarded safe by Food and Drug Administration (FDA) (Wong 2011). Due to its non-toxic, non-immunogenic natures as well as its biocompatibility and biodegradation properties (Mooney & Lee 2012), alginate has found a wide range of applications in the medical field.…”

Oral calcium pectinate-insulin nanoparticles: influences of alginate, sodium chloride and Tween 80 on their blood glucose lowering performance

“…The viscosity of guluronic acid‐rich alginate liquid increased to a greater extent than that of mannuronic acid‐rich alginate liquid when calcium‐pectinate‐insulin nanoparticles were added into these dispersants (Figure ). The guluronic acid residues of alginate were known for its high reactivity to Ca 2+ in comparison with mannuronic acid units [25]. A greater reaction propensity between guluronic acid‐rich alginate liquid with Ca 2+ from calcium pectinate‐insulin nanoparticles was expected via Ca 2+ /Na + exchange between calcium pectinate and sodium alginate, thus raising the liquid viscosity.…”

Nanoparticulate Assembly of Mannuronic Acid-and Guluronic Acid-Rich Alginate: Oral Insulin Carrier and Glucose Binder

“…Alginate is a nontoxic, biodegradable, nonimmunogenic, and biocompatible polymer . It possesses several inherent biological effects such as anticholesterolaemic, antihypertensive, antidiabetic, antiobesity, antimicrobial, anticancer, antihepatotoxicity, wound healing, anticoagulation, and coagulation activities . The biological effects of alginate have been indicated to be attributed to its structural assembly and physicochemical features.…”

“…Low molecular weight alginate has been widely used as the matrix substance of oral insulin nanoparticles . Though low molecular weight alginate inherently possesses antidiabetic activity, the matrix made of such polymer releases drugs at a fast rate . Alginate's uronic acid composition can critically affect drug release characteristics of a matrix as a function of matrix pore, crack, lamination, and diffusion barrier formation .…”

“…Though low molecular weight alginate inherently possesses antidiabetic activity, the matrix made of such polymer releases drugs at a fast rate . Alginate's uronic acid composition can critically affect drug release characteristics of a matrix as a function of matrix pore, crack, lamination, and diffusion barrier formation . The construction of oral insulin nanoparticles has nonetheless yet to consider from the viewpoint of uronic acid composition of alginate.…”