In vitro release study of diltiazem hydrochloride from poly(vinyl pyrrolidone)/sodium alginate blend microspheres

Polymeric blend microspheres of poly(vinyl pyrrolidone) (PVP) with sodium alginate (NaAlg) were prepared by cross‐linking with calcium ions and used to deliver a calcium channel blocker drug, diltiazem hydrochloride (DT). The prepared microspheres were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Scanning electron microscopy confirmed the spherical nature of the particles. Preparation conditions for the microspheres were optimized by considering the percentage entrapment efficiency, particle size, and swelling capacity. Effects of variables such as PVP/NaAlg ratio, molecular weight of PVP, cross‐linker concentration, and drug/polymer ratio on the release of DT were discussed at two different pH values (1.2, 6.8) at 37°C. It was observed that DT release from the microspheres decreased with increasing molecular weight of PVP and extent of cross‐linking. However, DT release increased with increasing PVP content and drug/polymer ratio (d/p) of the blend microspheres. The highest DT release percentage was obtained as 99% for PVP/NaAlg ratio of 1/2 with d/p ratio of 1/2 at the end of 4 h. It was also observed from release results that DT delivery from the microspheres through the external medium are much higher at low pH (1.2) value than that of high pH (6.8) value. The drug release from the microspheres mostly followed Fickian transport. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Controlled release of naproxen from sodium alginate and poly(vinyl alcohol)/sodium alginate blend beads crosslinked with glutaraldehyde

In this study, polymeric beads of sodium alginate (NaAlg) and its blend with poly(vinyl alcohol) (PVA) were prepared by crosslinking with glutaraldehyde (2.5% v/v) and hydrochloric acid (3% v/v) for the release of naproxen sodium (NS). The prepared beads were characterized with Fourier transform infrared spectroscopy, and pictures of the beads were determined with an optic microscope. The release studies were carried out at three pH values (1.2, 6.8, and 7.4) for 2 h. The effects of the preparation conditions, including the PVA/NaAlg (w/w) ratio, drug/polymer (w/w) ratio, and time of exposure to the crosslinker, on the release of NS were investigated for 10 h at 37°C. The release of NS decreased with the PVA/NaAlg (w/w) ratio and drug/polymer ratio increasing. At the end of 10 h, the highest release of NS was found to be 84% for the 1/2 PVA/NaAlg (w/w) ratio. The swelling measurements of the beads supported the release results. The release kinetics were described with Fickian and non‐Fickian approaches. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

In vitro release of salicylic acid through poly(vinyl alcohol‐g‐itaconic acid) membranes

In this study, itaconic acid (IA) was grafted on poly(vinyl alcohol) (PVA) at two different grafting percentages, 7.0% (w/w) and 14.0% (w/w), and membranes were prepared from the grafted copolymer (PVA‐g‐IA). Performances of PVA and PVA‐g‐IA membranes for the transdermal release of salicylic acid (SA) at in vitro conditions were investigated by using 2.0 mg/mL SA solutions. Effect of the pH on the release of SA was studied by keeping pH of donor and acceptor solutions in a range of (2.1–7.4). Permeation studies were also carried on at different SA concentrations. Effect of temperature on the release of SA was investigated in the temperature range of (32–39) (±1)°C. Results showed that presence of IA decreased the release of SA from the PVA membranes and 73% SA was released at the end of 48 h at (32 ± 1)°C from the IA‐1 membranes. pH affected the release of SA through the grafted membranes and studies showed that release of SA was high with donor solution pH of 2.1. When the pH of donor and receiver solutions were kept at the same pH value, the overall SA% in permeate increased. Increase in concentration of SA decreased the release of SA for the studied membranes. Release of SA from PVA‐g‐IA membranes was temperature sensitive and increase in temperature from (32 ± 1)°C to (39 ± 1)°C increased the release percentage of SA by 24% (w/w). The overall activation energy for the permeation of SA through IA‐1 membrane was found to be 22.97 kJ/mol. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of sodium alginate/poly(vinyl alcohol) blend microspheres for controlled release applications

Sodium alginate (NaAlg)/poly (vinyl alcohol) (PVA) blend microspheres (MS) were prepared by water-in-oil (w/o) emulsion method. These polymer microspheres were crosslinked with glutaraldehyde and loaded with metformin hydrochloride (MHC). The microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis to confirm the molecular dispersion of the drug, thermal stability, morphological properties, and crystallinity of the polymer matrix before and after blending. SEM of the microspheres suggested the formation of microspheres in spherical structure. Drug release data were analyzed using an empirical equation to understand the nature of drug transport through polymeric matrices. The controlled release (CR) characteristics of the polymer matrices was investigated in pH 7.4 media and from the results it was obtained that the drug was released in controlled manner up to 10 h. The physico-chemical properties of the microspheres were studied by calculating drug entrapment efficiency and drug release kinetics. Percent of encapsulation efficiency (% EE) decreased with increase in crosslinking agent (GA) and PVA content in the microspheres. The optimum % EE (80%) was observed in case of MS containing 40% of PVA with 15% MHC. The release profiles indicate that the release of MHC decreases with increasing the PVA/NaAlg (w/w) and drug/polymer ratio. At the end of 10 h, the highest release of MHC was found to be 96% for MS containing PVA/NaAlg (40 : 60) and 15 wt % drug loaded. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Release of salicylic acid through poly(vinyl alcohol)/poly(vinyl pyrrolidone) and poly(vinyl alcohol‐g‐N‐vinyl‐2‐pyrrolidone) membranes

A controlled release profile of salicylic acid (SA) for transdermal administration has been developed. Poly (vinyl alcohol) (PVA) and Poly(vinyl alcohol)/Poly(vinyl pyrrolidone) (PVP) blended preparations were used to prepare the membranes by solvent‐casting technique. The release of the drug from the membranes was evaluated at in vitro conditions. The effects of PVA/PVP (v/v) ratio, pH, SA concentration and temperature were investigated. 60/40 (v/v) PVA/PVP ratio was found to be the best ratio for the SA release. Increase in pH and temperature was observed to increase the transport of SA. Instead of blending PVA with PVP, N‐Vinyl‐2‐pyrrolidone (VP) was grafted onto the PVA and the delivery performance for SA was compared with that of the blended PVA/PVP membranes. Grafted membranes gave higher transport percentages than the blended membranes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1244–1253, 2006     

Release of diclofenac through gluteraldehyde crosslinked poly(vinyl alcohol)/poly(acrylic acid) alloy membranes

A controlled‐release preparation of diclofenac sodium for transdermal administration has been developed. Poly(vinyl alcohol) (PVA) and PVA/poly(acrylic acid) (PAA) alloy membranes were prepared from a solvent‐casting technique using different PVA/PAA (v/v) ratios. The release of the drug from the membrane was evaluated under in vitro conditions at pH 7.4. The delivery system provided linear release without time lag, burst effect, and boundary layer resistance. Effects of variables such as film thickness and PVA/PAA ratio on the permeation behavior of the polymeric membranes were discussed. The optimal PVA/PAA was determined as 50/50. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 72–77, 2004     

Novel blend microspheres of poly(3‐hydroxybutyrate) and Pluronic F68/127 for controlled release of 6‐mercaptopurine

The objective of this article is to investigate the controlled release characteristics of 6‐mercaptopurine (6‐MP) loaded microspheres prepared from the blends of poly(3‐hydroxybutyrate) (PHB) and Pluronic F68/127 by the oil‐in‐water emulsion‐solvent evaporation technique. Formulations were prepared by taking different ratios of individual polymer components to achieve a maximum 79% encapsulation and extending the release time up to 24 h. Differential scanning calorimetry (DSC) suggested reduction in crystallanity of PHB after blending with Pluronic F127. The absence of chemical interactions between 6‐MP and the blend matrix was confirmed by Fourier transform infrared (FTIR) spectroscopy, while the size of microspheres measured by optical microscopy ranged between 30 and 47 μm. X‐ray diffraction (XRD) confirmed the crystalline nature of 6‐MP even after encapsulation and surface morphology of the microspheres was investigated by scanning electron microscopy (SEM). In vitro release of 6‐MP at 37°C in pH 7.4 phosphate buffer media indicated a dependence on the composition of Pluronic in the blend. The release data have been fitted to empirical equations to understand the release profile of 6‐MP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40196.     

In vitro silver ion release kinetics from nanosilver/poly(vinyl alcohol) hydrogels synthesized by gamma irradiation

A nanosilver (nano‐Ag)/poly(vinyl alcohol) (PVA) hydrogel device was synthesized with γ irradiation because it is a highly suitable tool for enhanced nano‐Ag technologies and biocompatible controlled release formulations. The amount of the Ag⁺ ions released in vitro by the nano‐Ag/PVA hydrogel device was in the antimicrobial parts per million concentration range. The modeling of the Ag⁺ ion release kinetics with the elements of the drug‐delivery paradigm revealed the best fit solution (R² > 0.99) for the Kopcha and Makoid–Banakar's pharmacokinetic dissolution models. The term A/B, derived from the Kopcha model, indicated that the nano‐Ag/PVA hydrogel was mainly an Ag⁺‐ion diffusion‐controlled device. Makoid–Banakar's parameter and the short time approximated Ag⁺‐ion diffusion constant reflected the importance of the size of the Ag nanoparticles. However, it appeared that the cell oxidation potential of the Ag nanoparticles depended on the diffusion characteristics of the fluid penetrating into the Ag/PVA nanosystem. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40321.     

Electrospun poly(vinyl alcohol) composite nanofibers with halloysite nanotubes for the sustained release of sodium d‐pantothenate

Poly(vinyl alcohol) (PVA) nanofibers containing halloysite nanotubes (HNTs) loaded with sodium d ‐pantothenate (SDP) were successfully fabricated via simple blend‐electrospinning. SDP was efficiently loaded into the innate HNT lumen with an SDP/HNT mass ratio of 1.5:1 via vacuum treatment. The SDP‐loaded HNT‐inclusion complex was evaluated with drug‐loading efficiency testing, Fourier transform infrared (FTIR) spectroscopy, and X‐ray diffraction. The morphologies of the nanofibers were observed by scanning electron microscopy, which revealed uniform and smooth surfaces of the nanofibers. The addition of HNTs to the composite nanofibers increased the viscosity of the polymer solution, and this suggested shorter fiber diameters. FTIR spectroscopy verified the good compatibility of the SDP and HNTs with PVA. Moreover, the swelling properties were found to quantitatively correlate with weight loss. In vitro drug‐release testing revealed that the HNTs and crosslinking reaction most dramatically affected the sustained release of SDP from the PVA and SDP‐loaded HNT complex. In the drug‐release kinetics model, SDP release depended on the diffusion caused by the deformation of the polymer‐based structures in the medium; it followed Fickian diffusion with acceptable coefficient of determination (r²) values between 0.88 and 0.94. Most importantly, the HNTs as natural biocontainers effectively modulated the release profile by loading the active compound in harmony with the electrospun nanofibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42900.     

Exploring poly(vinyl alcohol) hydrogels containing drug–cyclodextrin complexes as controlled drug delivery systems

Poly(vinyl alcohol) (PVA) hydrogels containing drug–β‐cyclodextrin inclusion complexes (ICs) were synthesized with glutaraldehyde (GA) as a crosslinker. The role of cyclodextrin (CD), the effect of the nature of drug, and the degree of crosslinking on the drug‐release process were investigated. The probable mechanism of drug release was also explored. Controlled release of the drug was achieved from the hydrogels containing the ICs. The nature of the drug, in terms of its binding efficacy with CD, played an important role. The effect of the degree of crosslinking on the release pattern was strikingly different from that in the hydrogels containing free drug and those with ICs. The role of CD in the drug‐release process was not only due to its inclusion ability but also its effect on the polymer relaxation. GA, apart from crosslinking PVA, probably interacted with the cyclodextrins and, thereby, influenced the matrix structure and the drug‐release kinetics. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40318.     

Synthesis and characterization of poly(N‐vinyl‐2‐pyrrolidone) grafted sodium alginate hydrogel beads for the controlled release of indomethacin

Graft copolymers of sodium alginate (NaAlg) with N‐vinyl‐2‐pyrrolidone were prepared using azobisisobutyronitrile as initiator. The graft copolymers (NaAlg‐g‐PVP) were characterized with Fourier transform infrared spectroscopy, elemental analysis, and differential scanning calorimetry. Polymeric hydrogel beads of NaAlg and NaAlg‐g‐PVP were prepared by crosslinking method using glutaraldehyde (GA) as a crosslinker in the hydrochloric acid catalyst (HCl) and these beads were used to deliver anti‐inflammatory drug, indomethacin (IM). Chemical stability of the IM after encapsulation into beads was confirmed by FTIR. Preparation conditions of the NaAlg‐g‐PVP beads were optimized by considering the percentage entrapment efficiency, particle size, swelling capacity and their release data. In vitro release studies were performed in simulated gastric fluid (pH 1.2) for the initial 2 h, followed by simulated intestinal fluid (pH 7.4) for 4 h. Effects of GA concentration, exposure time to GA, drug/polymer (d/p) ratio, and concentration of HCl on the release of IM were discussed. It was observed that IM release from the beads decreased with increasing GA concentration and exposure time. IM release also decreases with increasing d/p ratio and HCl concentration. The highest IM release was obtained to be 77% for beads crosslinked with 0.027M GA. Swelling experiments were also performed to compute molecular mass between crosslinks of the beads. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis,characterization, and drug release activity of structurally modified poly(vinyl alcohol)

The main aim of the present investigation is synthesis of drug‐grafted poly(vinyl alcohol) (PVA) for sustainable drug release in order to avoid bulk release and unwanted side effects. Here, the PVA was structurally modified with five different drug molecules in DMSO medium at 85 °C under N₂ atmosphere for 2 h. The structure of modified PVA was confirmed by FTIR and ¹H NMR spectra and further it was characterized by TGA, DSC, and SEM. The tensile strength and % elongation for the structurally modified PVA were determined. The FTIR spectrum showed peaks corresponding to the C?O and C? S stretching due to the grafted drug molecules. The ¹H NMR spectrum showed the acrylic CH₂ proton signal of PVA around 1.6 ppm. The SEM showed different surface morphology for the structurally modified PVA. The mechanical properties of the structurally modified PVA was found to be reduced due to the presence of traces of solvent molecules and the breaking of inter‐ and intramolecular hydrogen bonding. The sustainable drug release through hydrolysis mechanism was tested at the pH of 7.3. Generally, the drug release followed the Korsmeyer–Peppas model with Fickian drug transportation mechanism except Furosemide (Fur)‐grafted PVA system at the pH of 7.3. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46620.     

Properties of chitosan/poly(vinyl alcohol) films for drug‐controlled release

With bovine serum albumin (BSA) as a model drug, drug‐loaded films of chitosan (CS) and poly(vinyl alcohol) (PVA) were obtained by a casting/solvent evaporation method and crosslinked by tripolyphosphate (TPP). The films were characterized by FTIR, XRD, and SEM. The influential factors of drug‐loaded films on drug‐controlled release were studied. These factors included, primarily, the component ratio of CS and PVA, the loaded amount of BSA, the pH and ionic strength of the release solution, and the crosslinking time with TPP. The results showed that within 25 h, when the weight ratios of CS to PVA in the drug‐loaded films were 90 : 10, 70 : 30, 50 : 50, and 30 : 50, the cumulative release rates of BSA were 63.3, 72.9, 81.8, and 91.8%, respectively; when the amounts of model drug were 0.1, 0.2, and 0.3 g, the release rates were 100, 81.8, and 59.6%, respectively; when the pH values of the drug release medium were 1.0, 3.8, 5.4, and 7.4, the release rates reached 100, 100, 37.9, and 7.8%, respectively; the cumulative release rates of BSA were 78.4, 82.3, 84.3, and 91.7% when the ionic strengths of the release solution were, respectively, 0.1, 0.2, 0.3, and 0.4M; when the crosslinking times of these drug films in the TPP solution were 0, 5, 15, 30, and 60 min, the release rates attained 100, 100, 81.8, 65, and 43.3%, respectively. All the results indicated that the CS/PVA film was useful in drug delivery systems. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 808–813, 2005     

Sustained release behavior of pH‐responsive poly(vinyl alcohol)/poly(acrylic acid) hydrogels containing activated carbon fibers

The composites of pH‐responsive poly(vinyl alcohol)/poly(acrylic acid) hydrogel and activated carbon fibers (ACFs) were prepared as sustained drug release system with excellent mechanical properties. The mechanical properties of hydrogels were improved greatly by addition of ACFs. The thinner ACFs were more effective in increasing the mechanical properties of composite hydrogels. The cumulative amount of release and the release period were dependent on the surface area and the pore volume of ACFs. The drug release was maximized at basic condition due to the pH‐sensitive hydrogel matrices and the initial bust phenomenon was alleviated by incorporating ACFs in the hydrogels. The drug release was sustained about four times longer and the mechanical property was increased about 2.6 times higher because ACFs worked as drug reservoir and reinforcement. Cytotoxicity evaluation confirmed the biocompatible characteristics of the ACFs‐containing hydrogels. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and characterization of chitosan/poly(vinyl alcohol) blend fibers

Chitosan and poly(vinyl alcohol) blend fibers were prepared by spinning their solution through a viscose‐type spinneret at 25°C into a coagulating bath containing aqueous NaOH and ethanol. The influence of coagulation solution composition on the spinning performance was discussed, and the intermolecular interactions of blend fibers were studied by infrared analysis (IR), X‐ray diffraction (XRD), and scanning electron micrograph (SEM) and by measurements of mechanical properties and water‐retention properties. The results demonstrated that the water‐retention properties and mechanical properties of the blend fibers increase due to the presence of PVA in the chitosan substract, and the mechanical strength of the blends is also related to PVA content and the degree of deacetylation of chitosan. The best mechanical strength values of the blend fibers, 1.82 cN/d (dry state) and 0.81 cN/d (wet state), were obtained when PVA content was 20 wt % and the degree of deacetylation of chitosan was 90.2%. The strength of the blend fibers, especially wet tenacity could be improved further by crosslinking with glutaraldehyde. The water‐retention values (WRV) of the blend fibers were between 170 and 241%, obviously higher than pure chitosan fiber (120%). The structure analysis indicated that there are strong interaction and good miscibility between chitosan and poly(vinyl alcohol) molecular resulted from intermolecular hydrogen bonds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2558–2565, 2001     

Synthesis,characterization, and drug‐release behavior of amphiphilic quaternary ammonium chitosan derivatives

A new type of amphiphilic quaternary ammonium chitosan derivative, 2‐N‐carboxymethyl‐6‐O‐diethylaminoethyl chitosan (DEAE–CMC), was synthesized through a two‐step Schiff base reaction process and applied to drug delivery. In the first step, benzaldehyde was used as a protective agent for the incorporation of diethylaminoethyl groups to form the intermediate (6‐O‐diethylaminoethyl chitosan). On the other hand, NaBH₄ was used as a reducing agent to reduce the Schiff base, which was generated by glyoxylic acid, for the further incorporation of carboxymethyl groups to produce DEAE–CMC. The structure, thermal properties, surface morphology, and diameter distribution of the resulting chitosan graft copolymers were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, thermogravimetric analysis, differential scanning calorimetry, X‐ray powder diffraction, scanning electron microscopy, and laser particle size analysis. Benefiting from the amphiphilic structure, DEAE–CMC was able to be formed into microspheres in aqueous solution with an average diameter of 4.52 ± 1.21 μm. An in vitro evaluation of these microspheres demonstrated their efficient controlled release behavior of a drug. The accumulated release ratio of vitamin B₁₂ loaded DEAE–CMC microspheres were up to 93%, and the duration was up to 15 h. The grafted polymers of DEAE–CMC were found to be blood‐compatible, and no cytotoxic effect was shown in human SiHa cells in an MTT [3‐(4, 5‐dimethyl‐thiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] cytotoxicity assay. These results indicate that the DEAE–CMC microspheres could be used as safe, promising drug‐delivery systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39890.     

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

The utilization of poly (2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) as a matrix for the controlled release of 5-aminosalicylic acid was investigated. Grafted copolymers of 2-hydroxyethylmethacrylate (HEMA) monomers on agar were synthesized by microwave assisted method. In vitro drug release studies were performed at pH values of 2 and 7 in order to investigate the possibility of pH triggered release for colon targeted drug delivery. Further, the percent grafting vs. t₅₀ (the time taken for release of 50% of the enclosed drug) value was studied and the results indicate that it may be possible to develop a programmable drug release matrix based on grafted polysaccharide. Ag-g-P(HEMA) appears to be a useful matrix for controlled release.     

Preparation and properties of physically crosslinked sodium carboxymethylcellulose/poly(vinyl alcohol) complex hydrogels

A series of physically crosslinked complex hydrogels of poly(vinyl alcohol) (PVA) and sodium carboxymethylcellulose (CMC) were prepared via physical mixing and a freeze/thaw technique. The morphology of the CMC/PVA complex gels was analyzed with differential scanning calorimetry and wide‐angle X‐ray diffraction. It was found that the crystallinity and melting temperature of the complex gels decreased, whereas the glass‐transition temperature increased, with an increase in the content of CMC. The reswelling of the complex gels was pH‐responsive and relied on the content of CMC and the freeze/thaw cycles. A network structure model of the complex gel was presented. PVA crystalline regions served as physical crosslinks; the interaction between CMC and PVA resulted in intramolecular entanglements. It was also found that the model drug hemoglobin was released completely from the complex hydrogels in 4 h, and its release rate increased with an increase in the content of CMC. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and release kinetics of carboxymethyl chitosan/cellulose acetate microspheres as drug delivery system

Carboxymethyl chitosan, a water soluble chitosan derivative, was prepared from chitosan using monochloroacetic acid. Carboxymethyl chitosan/cellulose acetate microspheres (CCM) were prepared using the method of W/O/W and emulsification solvent evaporation as drug delivery system. The CCMs prepared were spherical, free‐flowing, and nonaggregated with the smooth appearance and many small pores on the surface. All CCMs prepared had sustained release efficiency for acetaminophen and the optimal formulation was that carboxymethyl chitosan of 2.0% and 1360 KD. In addition, the release rate of drug from CCMs in dilute hydrochloric acid was much slower than that in phosphate buffer saline (pH 6.8) during 24 h. It is illustrated that the drug loaded in CCMs released slower in simulated gastric fluid than that in simulated intestinal fluid. Furthermore, the drug release data showed better fitness with the first order model which indicated that the drug release from CCMs was depended on the drug concentration in the polymeric networks. And the release of drug from CCMs indicated diffusion‐controlled drug release based on Fickian diffusion and accompanied with anomalous transport (i.e., non‐Fickian diffusion) according to the values obtained from Higuchi model and Peppas models. So it was shown that the CCMs might be an ideal sustained release system for acid‐labile drugs both for the solubility of carboxymethyl chitosan and the release media. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42152.     

Preparation and drug‐release behavior of minocycline‐loaded poly[hydroxyethyl methacrylate‐co‐poly(ethylene glycol)–methacrylate] films

In this work, biocompatible hydrogel matrices for wound‐dressing materials and controlled drug‐release systems were prepared from poly[hydroxyethyl methacrylate‐co‐poly(ethylene glycol)–methacrylate] [p(HEMA‐co‐PEG–MA] films via UV‐initiated photopolymerization. The characterization of the hydrogels was conducted with swelling experiments, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis (differential scanning calorimetry), and contact‐angle studies. The water absorbency of the hydrogel films significantly changed with the change of the medium pH from 4.0 to 7.4. The thermal stability of the copolymer was lowered by an increase in the ratio of poly(ethylene glycol) (PEG) to methacrylate (MA) in the film structure. Contact‐angle measurements on the surface of the p(HEMA‐co‐PEG–MA) films demonstrated that the copolymer gave rise to a significant hydrophilic surface in comparison with the homopolymer of 2‐hydroxyethyl methacrylate (HEMA). The blood protein adsorption was significantly reduced on the surface of the copolymer hydrogels in comparison with the control homopolymer of HEMA. Model antibiotic (i.e., minocycline) release experiments were performed in physiological buffer saline solutions with a continuous flow release system. The amount of minocycline release was shown to be dependent on the HEMA/PEG–MA ratio. The hydrogels have good antifouling properties and therefore are suitable candidates for wound dressing and other tissue engineering applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009