Hydrophobically modified alginate for extended release of pharmaceuticals

Abstract

Hydrophobically modified alginate hydrogels have great potential in drug delivery as they are biologically compatible and cost efficient. While previous works have shown successful protein, and hydrophobic and hydrophilic drug delivery, little information regarding the relationship between crosslinker density and drug release rate is known. This paper investigates the impact of crosslinker density and hydrophobic degree of substitution within modified alginate gels and solutions on the release kinetics using model hydrophobic drug, sulindac. Near zero-order release was obtained for an extended period of 5 days. Drug release rates decreased as the crosslinker density within both modified alginate hydrogels and solutions increased. Release data fit well to a simplified Fickian relationship, suggesting that the release mechanism is diffusion-limited. These release characteristics also correlate with bulk rheological measurements, indicating a strong interrelationship between the mechanical properties and the drug release characteristics of the hydrogels.

Alginate-Based Encapsulation Fabrication Technique for Drug Delivery: An Updated Review of Particle Type, Formulation Technique, Pharmaceutical Ingredient, and Targeted Delivery System

“…Propylene glycol alginate displays lower viscosity due to disrupted polymer–solvent interactions. Hydrophobically modified alginates demonstrate shear-thinning viscosity desirable for controlled drug release [ 29 ].…”

Amphiphilic Graft Copolymers of Quaternized Alginate-g-Polytetrahydrofuran for Anti-protein Surfaces, Curcumin Carriers, and Antibacterial Materials

“…Natural polysaccharides have been widely used in various fields involving cosmetics, textiles, , food additives, and medical areas. − Sodium alginate (SA) is a water-soluble linear biopolymer consisting of 1-4-linked α- l -guluronic (G) and β- d -mannuronic (M) acid residues with wide availability, well-documented biocompatibility, and biodegradability. − However, the insolubility in common solvents, lack of antibacterial activity, and burst release behavior while acting as drug carriers impede its large-scale application in the complicated human body environment . Many research studies have been devoted to ameliorate the solubility, antibacterial properties, and drug encapsulation ability of alginates such as graft copolymerization. , To combine the properties of various polymers, a series of alginate-based graft copolymers, for example, with poly­( N -isopropylacrylamide), − polyethylene glycol (PEG), polyacrylamide, − poly­(acrylic acid), , polymethyl methacrylate, , polycaprolactone, and gum arabic branches have been synthesized for extensive applications including drug carriers, − , absorbents, ,, food packaging, wound dressing, , injectable hydrogels, and antibacterial materials . The above SA- g -PEG-based drug delivery system exhibits enhanced mucoadhesion and prolonged drug retention time .…”

“…11 Many research studies have been devoted to ameliorate the solubility, antibacterial properties, and drug encapsulation ability of alginates such as graft copolymerization. 12,13 To combine the properties of various polymers, a series of alginate-based graft copolymers, for example, with poly(N-isopropylacrylamide), 14−16 polyethylene glycol (PEG), 17 polyacrylamide, 18−20 poly(acrylic acid), 21,22 polymethyl methacrylate, 23,24 polycaprolactone, 25 and gum arabic 26 branches have been synthesized for extensive applications including drug carriers, [15][16][17]20 absorbents, 18,21,22 food packaging, 24 wound dressing, 19,26 injectable hydrogels, 15 and antibacterial materials. 19 The above SA-g-PEG-based drug delivery system exhibits enhanced mucoadhesion and prolonged drug retention time.…”

Nonleaching antimicrobial poly(vinyl alcohol)/polyhexamethylene guanidine hydrochloride hydrogels reinforced by hydrogen bond

“…Hydrogels with 3D networks have excellent properties such as biocompatibility, 1 flexibility, high water content, tunable mechanical properties, 2‐5 and stimuli responsive 6‐9 . They have broad applications in the biomedical field, such as drug delivery, 10,11 controlled release of drugs, 12‐14 cartilage reconstruction, 15,16 cell therapy carrier, 17 wound dressing, 18 and so on. Poly(vinyl alcohol) (PVA) with hydrophilic, nontoxic, biocompatible, and biodegradable characteristics, is a common matrix for hydrogels.…”