Controlled release of aminophylline from poly (N‐isopropylacrylamide‐co‐itaconic acid) hydrogels

N‐Isopropylacrylamide (NIPA) has been copolymerized with itaconic acid (IA) in the presence of N,N‐methylenebisacrylamide (BIS) as crosslinker. The swelling capacity and the release rate of aminophylline at 37 °C are reported. Maximum equilibrium swelling increases as the itaconic acid content in the hydrogel increases. The experimental data suggest clearly that the swelling process obeys second‐order kinetics. According to this, the kinetic constant, k, and the maximum equilibrium swelling, W_∞, have been calculated. Drug release from fully swollen hydrogels follows Fick's law closely, but deviates from it for xerogels. © 2001 Society of Chemical Industry     

Release of vitamin B12 from poly(N‐vinyl‐2‐pyrrolidone)‐crosslinked polyacrylamide hydrogels: A kinetic study

Hydrogels, composed of poly(N‐vinyl‐2‐pyrrolidone) and crosslinked polyacrylamide, were synthesized and the release of vitamin B₁₂ from these hydrogels was studied as a function of the degree of crosslinking and pH of the external swelling media. The three drug‐loaded hydrogel samples synthesized with different crosslinking ratios of 0.3, 0.7, and 1.2 (in mol %) follow different drug‐release mechanisms, that is, chain relaxation with zero‐order, non‐Fickian and Fickian, or diffusion‐controlled mechanisms. To establish a correlation between their swelling behavior and drug‐release mechanism, the former was studied by the weight‐gain method and, at the same time, the concentration of the drug released was studied colorimetrically. Various swelling parameters such as the swelling exponent n, gel‐characteristic constant k, penetration velocity v, and diffusion coefficient D were evaluated to reflect the quantitative aspect of the swelling behavior of these hydrogels. Finally, the drug‐release behavior of the hydrogels was explained by proposing the swelling‐dependent mechanism. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1706–1714, 2000     

pH‐sensitive swelling and release behaviors of anionic hydrogels for intelligent drug delivery system

The pH‐sensitive swelling and release behaviors of the anionic P(MAA‐co‐EGMA) hydrogels were investigated as a biological on–off switch for the design of an intelligent drug delivery system triggered by external pH changes. There was a drastic change of the equilibrium weight swelling ratio of P(MAA‐co‐EGMA) hydrogels at a pH of around 5, which is the pK_a of poly (methacrylic acid) (PMAA). At a pH below 5, the hydrogels were in a relatively collapsed state but at a pH higher than 5, the hydrogels swelled to a high degree. When the molecular weight of the pendent poly(ethylene glycol) (PEG) of the P(MAA‐co‐EGMA) increased, the swelling ratio decreased at a pH higher than 5. The pK_a values of the P(MAA‐co‐EGMA) hydrogels moved to a higher pH range as the pendent PEG molecular weight increased. When the feed concentration of the crosslinker of the hydrogel increased the swelling ratio of the P(MAA‐co‐EGMA) hydrogels decreased at a pH higher than 5. In release experiments using Rhodamine B (Rh‐B) as a model solute, the P(MAA‐co‐EGMA) hydrogels showed a pH‐sensitive release behavior. At low pH (pH 4.0) a small amount of Rh‐B was released while at high pH (pH 6.0) a relatively large amount of Rh‐B was released from the hydrogels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Heterogeneous and homogeneous structure dextran–poly(methacrylic acid) interpenetrating network hydrogels: synthesis and an application study

pH‐sensitive dextran–poly(methacrylic acid) (Dext–pMeAc) full interpenetrating network hydrogels (INHs) were prepared by simultaneous radical polymerization of methacrylic acid monomer (MeAc) and Dext polymer chains in the presence of N,N‐methylenebisacrylamide (MBA) as crosslinker in aqueous solution. These hydrogels were investigated as a drug carrier. The influence of MeAc and MBA contents in the network hydrogels on the swelling behaviour and mechanical strength of prepared Dext–pMeAc INHs was evaluated. Dext–pMeAc INHs were characterized by Fourier transform IR spectroscopy, and kinetic swelling measurements were carried out in deionized water and in simulated gastric fluids (pH 1.1 and pH 7.4). Dext–pMeAc/1‐1, Dext–pMeAc/3‐1 and Dext–pMeAc/5‐1 hydrogels with molar ratios of n_Dext/n_MeAc = 10 and n_MBA/n_Dext = 10, 30 and 50 respectively showed a core–shell structure when they swelled. This phenomenon was not observed in Dext–pMeAc/5‐2, Dext–pMeAc/5‐3 and Dext–pMeAc/5‐5 hydrogels containing a higher amount of Dext in the gels. The swelling data proved the formation of INHs with pH‐sensitive behaviour. A drug release study was performed using Rhodamine 6G fluorescent dye as a model hydrophilic bioactive molecule. The in vitro release rate of Rhodamine 6G from Dext–pMeAc/5‐3 hydrogel was dependent on the pH of the release medium. Copyright © 2012 Society of Chemical Industry     

Dynamic swelling behavior of pH‐sensitive anionic hydrogels used for protein delivery

There have been many attempts to use anionic hydrogels as oral protein delivery carriers because of their pH‐responsive swelling behavior. The dynamic swelling behavior of poly(methacrylic acid‐co‐methacryloxyethyl glucoside) and poly(methacrylic acid‐g‐ethylene glycol) hydrogels was investigated to determine the mechanism of water transport through these anionic hydrogels. The exponential relation M_t/M_∞ = ktⁿ (where M_t is the mass of water absorbed at time t and M_∞ is the mass of water absorbed at equilibrium) was used to calculate the exponent (n) describing the Fickian or non‐Fickian behavior of swelling polymer networks. The mechanism of water transport through these gels was significantly affected by the pH of the swelling medium. The mechanism of water transport became more relaxation‐controlled in a swelling medium of pH 7.0, which was higher than pK_a of the gels. The experimental results of the time‐dependent swelling behaviors of the gels were analyzed with several mathematical models. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1606–1613, 2003     

Thermoreversible hydrogel. XVII. Investigation of the drug release behavior for [N‐isopropylacrylamide‐co‐trimethyl acrylamidopropyl ammonium iodide‐co‐3‐dimethyl (methacryloyloxyethyl) ammonium propane sulfonate] copolymeric hydrogels

A series of copolymeric hydrogels were prepared from various molar ratios of N‐isopropylacrylamide (NIPAAm), trimethyl acrylamidopropyl ammonium iodide (TMAAI), and 3‐dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS). Results showed that the swelling ratios of these copolymeric hydrogels increased with an increase of TMAAI content. The drug release behavior of the ionic thermosensitive hydrogels related to their ionicity and drug types. Results indicated that the release ratio of caffeine in the hydrogels was not affected by the ionicity of hydrogels, but increased with increasing of the swelling ratio. The anionic solute (phenol red) strongly interacted with cationic hydrogel (very large K_d), so the phenol red release ratio in cationic gels was very low. On the other hand, CV was adsorbed only on the skin layer of the cationic hydrogel because of the charge repulsion, and released rapidly. Therefore the release ratio was highest for cationic hydrogel to cationic drug. In addition, the partition coefficients (K_d) and the drug delivery behavior of the present gels were also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1592–1598, 2002     

Preparation of pH‐sensitive poly(vinyl alcohol‐g‐methacrylic acid) and poly(vinyl alcohol‐g‐acrylic acid) hydrogels by gamma ray irradiation and their insulin release behavior

A series of pH‐responsive hydrogels were studied as potential drug carriers for the protection of insulin from the acidic environment of the stomach before releasing in the small intestine. Hydrogels based on poly(vinyl alcohol) networks grafted with acrylic acid or methacrylic acid were prepared by a two‐step process. Poly(vinyl alcohol) hydrogels were prepared by gamma ray irradiation (50 kGy) and then followed by grafting either acrylic acid or methacrylic acid onto these poly(vinyl alcohol) hydrogels with subsequent irradiation (5–20 kGy). These graft hydrogels showed pH‐sensitive swelling behavior and were used as carriers for the controlled release of insulin. The in vitro release of insulin was observed for the insulin‐loaded hydrogels in a simulated intestinal fluid (pH 6.8) but not in a simulated gastric fluid (pH 1.2). The release behavior of insulin in vivo in a rat model confirmed the effectiveness of the oral delivery of insulin to control the level of glucose. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 636–643, 2004     

Synthesis and properties of hydrogels of poly(acrylic‐co‐acroloyl β‐cyclodextrin)

Novel acrylic monomers (β‐CD‐A and β‐CD‐6‐EA) containing β‐cyclodextrin (β‐CD) with different extent of substitution were prepared by using dicyclohexylcarbodiimide (DCC) as a condensation agent at room temperature. Two kinds of functional hydrogels were also synthesized by copolymerization of β‐CD‐A and β‐CD‐6‐EA with acrylic acid (AAc) using a redox initiator system in aqueous solution. The nuclear magnetic resonance (¹H NMR), infrared spectroscopy (IR), thermogravimetric analysis (TGA) were employed to character the molecular structures of β‐CD modified monomers and their copolymers. The swelling experiments indicate that the hydrogels with different equilibrium swelling ratio (ESR) possess obvious pH‐sensitivity and distinct dynamic swelling behavior. Using an anti‐cancer drug, chlorambucil (CHL), able to form complexes with β‐CD in water, as a model compound, the controlled drug release behaviors of these hydrogels were investigated. The release behavior of CHL from two kinds of hydrogels synthesized reveals that the release rate of CHL can be effectively controlled by pH values, cross‐linking density, and β‐CD content. In addition, it is found that the β‐CD with the proper frame and concentration can increase release efficiency of CHL from the hydrogels. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Photopolymerized pH‐sensitive semi‐IPN: Synthesis,water uptake analysis,and preliminary drug release study

A series of pH‐sensitive semi‐IPN hydrogels, composed of varying amounts of monomer acrylic acid(AAc), crosslinker N,N′ methylene bisacrylamide, polymer cellulose acetate (CA) were synthesized via photoinitiated polymerization in dimethyl formamide (DMF) medium. The CA/P (AAc) hydrogels were characterized by FTIR, and TG analysis. The equilibrium water uptake data was used to determine various network parameters. For all the samples synthesized, the swelling exponent “n,” initial diffusion coefficient D and average diffusion coefficient D_ave were found to be in the range of 0.51–0.72, 3.16 to 7.14 × 10^?6 cm² min^?1 and 94.16–120.56 cm² min^?1, respectively. The hydrogel demonstrated fair pH‐dependent swelling behavior, with nearly 20% swelling in the medium of pH 1.0 and 615% in the medium of pH 7.4 at 37°C, respectively. The gel showed excellent swelling–deswelling cycles which were interpreted quantitatively by first order kinetic swelling and deswelling models. Finally, the preliminary insulin release study, carried out in the media of varying pH, observed almost 16% release of entrapped drug in the simulating gastric fluid (SGF) of pH 1.0 in first 2 h and nearly 51% in next 6 h in simulating intestinal fluid(SIF) of pH 7.4 at 37°C. POLYM. ENG. SCI., 53:2129–2140, 2013. © 2013 Society of Plastics Engineers     

Physical properties of hydrogels of poly(2‐hydroxyethyl methacrylate) and copolymers with mono‐methyl itaconate synthesized by bulk and solution polymerization

The physical properties found during the swelling process of poly(2‐hydroxyethyl methacrylate) (PHEMA) and of copolymers of HEMA with mono‐n‐methyl itaconate, synthesized by solution and bulk polymerization, are reported. The swelling kinetics were followed at four different temperatures (295, 300, 305 and 310 K). Experimental data follow second‐order swelling kinetics, from where the kinetic rate constant k_∞ and the swelling capacity at equilibrium W_∞ were calculated as a function of temperature. The kinetic rate constant obeys Arrhenius behaviour. The following network parameters were determined for the hydrogels: Young's moduli E, effective crosslinking density v_e, molar mass per crosslink M_C, volume fraction ϕ₂ and polymer‐liquid interaction parameter χ. © 2000 Society of Chemical Industry     

Preparation and application in drug controlled delivery of pH‐sensitive P(CE‐co‐DMAEMA‐co‐MEG) hydrogel

A pH‐sensitive hydrogel [P(CE‐co‐DMAEMA‐co‐MEG)] was synthesized by the free‐radical crosslinking polymerization of N,N‐dimethylaminoethyl methacrylate (DMAEMA), poly(ethylene glycol) methyl ether methacrylate(MPEG‐Mac) and methoxyl poly(ethylene glycol)‐poly(caprolactone)‐methacryloyl methchloride (PCE‐Mac). The effects of pH and monomer content on swelling property, swelling and deswelling kinetics of the hydrogels were examined and hydrogel microstructures were investigated by SEM. Sodium salicylate was chosen as a model drug and the controlled‐release properties of hydrogels were pilot studied. The results indicated that the swelling ratios of the gels in stimulated gastric fluids (SGF, pH = 1.4) were higher than those in stimulated intestinal fluids (SIF, pH = 7.4), and followed a non‐Fickian and a Fickian diffusion mechanism, respectively. In vitro release studies showed that its release rate depends on different swelling of the network as a function of the environmental pH and DMAEMA content. SEM micrographs showed homogenous pore structure of the hydrogel with open pores at pH 1.4. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40737.     

Thermoreversible hydrogels X: Synthesis and swelling behavior of the (N‐isopropylacrylamide‐co‐sodium 2‐acrylamido‐2‐methylpropyl sulfonate) copolymeric hydrogels

A series of thermosensitive hydrogels were prepared from various molar ratios of N‐isopropylacrylamide (NIPAAm) and sodium‐2‐acrylamido‐2‐methylpropyl sulfonate (NaAMPS). Factors such as temperature and initial total monomer concentration and different pH solutions were investigated. Results indicated that the more the NaAMPS content in hydrogel system, the higher the swelling ratio and the gel transition temperature; the higher the initial monomer concentration, the lower the swelling ratio. The result also indicated that the NIPAAm/NaAMPS copolymeric hydrogels had different swelling ratios in various pH environments. The present gels showed a pH‐reversible property between pH 3 and pH 10 and thermoreversibility. The swelling ratios of copolymeric gels were lower in a strong alkaline environment because the gels were screened by counterions. Finally, the drug release behavior of these gels was also investigated in this article. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1760–1768, 2000     

pH‐ and temperature‐responsive IPN hydrogels based on soy protein and poly(N‐isopropylacrylamide‐co‐sodium acrylate)

pH‐ and temperature‐responsive interpenetrating polymer network (IPN) hydrogels based on soy protein and poly(N‐isopropylacrylamide‐co‐sodium acrylate) were successfully prepared. The structure and properties of the hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analyzer. The equilibrium and dynamic swelling/deswelling behaviors and the drug release properties of the hydrogels responding to pH and/or temperature were also studied in detail. The hydrogels have the porous honeycomb structures, good miscibility and thermal stability, and good pH‐ and temperature‐responsivity. The volume phase transition temperature of the hydrogels is ca. 40°C. Changing the soy protein or crosslinker content could be used to control the swelling behavior and water retention, and the hydrogels have the fastest deswelling rate in pH 1.2 buffer solutions at 45°C. Bovine serum albumin release from the hydrogels has the good pH and temperature dependence. The results show that the proposed IPN hydrogels may have potential applications in the field of biomedical materials such as in drug delivery systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39781.     

Smart carboxymethylchitosan hydrogels that have thermo‐ and pH‐responsive properties

Thermo‐responsive poly(N‐isopropylacrylamide) (poly(NIPAAm)) and pH‐responsive poly(N,N′‐diethylaminoethyl methacrylate) (poly(DEAEMA)) polymers were grafted to carboxymethylchitosan (CMC) via radical polymerization to form highly water swellable hydrogels with dual responsive properties. Ratios of CMC, NIPAAm to DEAEMA used in the reactions were finely adjusted such that the thermo and pH responsiveness of the hydrogels was retained. Scanning electron microscopy (SEM) indicated the formation of an internal porous structure for the swollen CMC hydrogels upon incorporation of poly(NIPAAm) and poly(DEAEMA). Effect of temperature and pH changes on water swelling properties of the hydrogels was investigated. It was found that the water swelling of the hydrogels was enhanced when the solution pH was under basic conditions (pH 11) or the temperature was below its lower critical solution temperature (LCST). These responsive properties can be used to regulate releasing rate of an entrapped drug from the hydrogels, a model drug, indomethacin was used to demonstrate the release. These smart and nontoxic CMC‐based hydrogels show great potential for use in controlled drug release applications with controllable on‐off switch properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41505.     

Dual‐responsive semi‐interpenetrating network beads based on calcium alginate/poly(N‐isopropylacrylamide)/poly(sodium acrylate) for sustained drug release

To improve the mechanical strength of natural hydrogels and to obtain a sustained drug‐delivery device, temperature‐/pH‐sensitive hydrogel beads composed of calcium alginate (Ca‐alginate) and poly(N‐isopropylacrylamide) (PNIPAAm) were prepared in the presence of poly(sodium acrylate) (PAANa) with ultrahigh molecular weight (M_η ≥ 1.0 × 10⁷) as a strengthening agent. The influence of PAANa content on the properties, including the beads stability, swelling, and drug‐release behaviors, of the hydrogels was evaluated. Scanning electron microscopy and oscillation experiments were used to analyze the structure and mechanical stability of the hydrogel beads, respectively. The results show that stability of the obtained Ca‐alginate/PNIPAAm hydrogel beads strengthened by PAANa the alginate/poly(N‐isopropyl acrylamide) hydrogel bead (SANBs) was significantly improved compared to that of the beads without PAANa (NANBs) at pH 7.4. The swelling behavior and drug‐release capability of the SANBs were markedly dependent on the PAANa content and on the environmental temperature and pH. The bead sample with a higher percentage of PAANa exhibited a lower swelling rate and slower drug release. The drug release profiles from SANBs were further studied in simulated intestinal fluid, and the results demonstrated here suggest that SANBs could serve as a potential candidate for controlled drug delivery in vivo. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

pH‐thermoreversible hydrogels. I. Synthesis and swelling behaviors of the (N‐isopropylacrylamide‐co‐acrylamide‐co‐2‐hydroxyethyl methacrylate) copolymeric hydrogels

A series of pH‐thermoreversible hydrogels that exhibited volume phase transition was synthesized by various molar ratios of N‐isopropylacrylamide (NIPAAm), acrylamide (AAm), and 2‐hydroxyethyl methacrylate (HEMA). The influence of environmental conditions such as temperature and pH value on the swelling behavior of these copolymeric gels was investigated. Results showed that the hydrogels exhibited different equilibrium swelling ratios in different pH solutions. Amide groups could be hydrolyzed to form negatively charged carboxylate ion groups in their hydrophilic polymeric network in response to an external pH variation. The pH sensitivities of these gels also depended on the AAm content in the copolymeric gels; thus the greater the AAm content, the higher the pH sensitivity. These hydrogels, based on a temperature‐sensitive hydrogel, demonstrated a significant change of equilibrium swelling in aqueous media between a highly solvated, swollen gel state and a dehydrated network response to small variations of temperature. pH‐thermoreversible hydrogels were used for a study of the release of a model drug, caffeine, with changes in temperature. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 221–231, 1999     

Synthesis and characterization of poly{N‐[3‐(dimethylamino) propyl] methacrylamide‐co‐itaconic acid} hydrogels for drug delivery

A novel pH‐sensitive hydrogel system composed of itaconic acid (IA) and N‐[3‐(dimethylamino) propyl] methacrylamide was designed. This system was prepared by aqueous copolymerization with N,N‐methylene bisacrylamide as a chemical crosslinker. The chemical structure of the hydrogels was characterized by Fourier transform infrared (FTIR) spectroscopy. The microstructure and morphology of the hydrogels were evaluated by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The SEM study of hydrogels on higher magnification revealed a highly porous morphology with uniformly arranged pores ranging from 40 to 200 μm in size. XRD analysis revealed the amorphous nature of the hydrogels, and it was found that an increase in the IA content in the monomer feed greatly reduced the crystallinity of the hydrogels. Swelling experiments were carried out in buffer solutions at different pH values (1.2–10) at 37°C ± 1°C to investigate their pH‐dependent swelling behavior and dimensional stability. An increase in the acid part (IA) increased the swelling ratio of the hydrogels. Temperature‐sensitive swelling of the hydrogels was investigated at 20–70°C in simulated intestinal fluid. The hydrogels swelled at higher temperatures and shrank at lower temperatures. 5‐Aminosalicylic acid (5‐ASA) was selected as a model drug, and release experiments were carried out under simulated intestinal and gastric conditions. 5‐ASA release from the poly N‐[3‐(dimethylamino) propyl] methacrylamide‐co‐itaconic acid‐80 (PDMAPMAIA‐80) hydrogel was found to follow non‐Fickian diffusion mechanism under gastric conditions, and a super case II transport mechanism was found under intestinal conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Swelling and drug‐release behavior of the poly(AA‐co‐N‐vinyl pyrrolidone)/chitosan interpenetrating polymer network hydrogels

A series of novel hydrogels were prepared from acrylic acid (AA), N‐vinyl pyrrolidone (NVP), and chitosan by photopolymerization. The swelling behavior, gel strength, and drug release behavior of the poly(AA/NVP) copolymeric hydrogels and corresponding interpenetrating polymer network hydrogels were investigated. Results showed that the swelling ratios for the present hydrogels decreased with an increase of NVP content in the gel, but the gel strength increased with an increase of NVP content in the gel. Results also showed that the drug‐release behavior for the gels is related to the ionicity of drug and the swelling ratio of the gel. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2135–2142, 2004     

Photo‐cross‐linked biodegradable thermo‐ and pH‐responsive hydrogels for controlled drug release

A new strategy was developed to prepare thermo‐ and pH‐sensitive hydrogels by the crosslinking of poly(N‐isopropylacrylamide) with a biodegradable crosslinker derived from poly(L ‐glutamic acid). Hydrogels were fabricated by exposing aqueous solutions of precursor containing photoinitiator to UV light irradiation. The swelling behaviors of hydrogels at different temperatures, pHs, and ionic strengths were examined. The hydrogels shrank under acidic condition or at temperature above their collapse temperature and would swell in neutral or basic media or at lower temperature. These processes were reversible as the pH or temperature changed. All hydrogels exhibited no weight loss in the simulated gastric fluid but degraded rapidly in the simulated intestinal condition. Bovine serum albumin were used as a model protein drug and loaded into the hydrogels. The in vitro drug release experiment was carried out at different pH values and temperatures. The pH and temperature dependent release behaviors indicated the promising application of these materials as stimuli‐responsive drug delivery vehicles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of 2‐hydroxyethylmethacrylate/2‐(3‐indol‐yl)ethylmethacrylamide‐based novel hydrogels as drug carrier with in vitro antibacterial properties

In this study, a new cationic monomer 2‐(3‐indol‐yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), ¹H‐NMR, and ¹³C‐NMR. Then, one‐step preparation of novel poly[2‐hydroxyethylmethacrylate‐c‐2‐(3‐indol‐yl)ethylmethacrylamide], or p(HEMA‐c‐IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2‐hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA‐c‐IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug‐release behavior of the hydrogels was determined as a function of time at 37 °C in pH 1.2 and 7.2. The swelling and drug‐release studies showed that an increased IEMA amount caused a higher increase in swelling and drug‐release values. Additionally, zero‐order, first‐order, and Higuchi equation kinetic models were applied to the drug‐release data, and the data fit well in the Higuchi model, and the Peppas power‐law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram‐positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Salmonella typhimurium). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45550.