Hydrogels of Dextran Containing Nonsteroidal Anti-Inflammatory Drugs as Pendant Agents

Figures & data

TABLE 1 Yield (%) of the hydrogels obtained after 60 min of irradiation (λ_max = 313 nm) of 7% (w/v) solutions of dextran-methacrylate (derivatization degree = 14) in different solvents

Solvent	Yield (%)
H2O	85.3 ± 1.5
DMF	90.5 ± 1.0
DMF/H2O (1:1)	84.2 ± 1.6
DMSO/H2O (1:1)	87.4 ± 1.3

Values are means ± SD, n = 3.

TABLE 2 Yields (%) of the hydrogels obtained in N,N-dimethylformamide from irradiation (λ_max = 313 nm) of solutions of dextran-methacrylate at different derivatization degree and concentration (w/v%) in the presence of methacryloyloxyethyl 2-phenylpropionate (2.5% w/v)

Derivatization	Polymer	Irradiation	Hydrogel
degree (DD)	concentration (w/v%)	time (hours)	yield (%)
20	5	3	97.0 ± 1.0
20	7	1	96.5 ± 1.5
20	9	1	94.5 ± 1.5
14	5	3	93.5 ± 1.0
14	7	1	95.5 ± 1.3
14	9	1	96.2 ± 1.6
8	5	3	82.8 ± 1.8
8	7	1	88.2 ± 1.0
8	9	1	93.5 ± 1.8

Values are means ± SD, n = 3.

FIG. 1 Schematic representation of the formation of the hydrogel having the functionalized drug chemically bound.

FIG. 2 FT-IR spectra of the functionalized drug (A), of DEX-MA (B), and of the corresponding gel (C).

FIG. 3 Release profiles [(M_t/M_∞) × 100] of 2-phenyl propionic acid from the hydrogels obtained by irradiation of solutions at different concentrations of DEX-MA (DD = 14), maintained at 37.0 ± 0.1°C at pH 6.0 in the presence of dextranases and esterases.

FIG. 4 Release profiles [(M_t/M_∞) × 100] of 2-phenyl propionic acid from the hydrogels obtained by irradiation of 5% solutions of DEX-MA with different derivatization degree, maintained at 37.0 ± 0.1°C at pH 6.0 in the presence of dextranases and esterases.

FIG. 5 Release profiles [(M_t/M_∞) × 100] of 2-phenyl propionic acid from the hydrogels having the drug bound to the matrix (▪ and physically entrapped (♦, maintained at 37.0 ± 0.1°C in HCl solution (pH 1.0) for 2 hr and at pH 6.0 in the presence of dextranases and esterases for further 6 hr.

FIG. 6 Release profiles [(M_t/M_∞) × 100] of ibuprofen from the hydrogels maintained at 37.0 ± 0.1°C in HCl solution (pH = 1.0) for 2 hr and at pH 6.0 in the presence of dextranases and esterases for further 6 hr.

FIG. 7 Release profiles [(M_t/M_∞) × 100] of acid (expressed as sum of O-acetylsalicylic and salicylic acid) from the hydrogels maintained at 37.0 ± 0.1°C in HCl solution (pH 1.0) for 2 hr and at pH 6.0 in the presence of dextranases and esterases for further 6 hr.