Interpenetrating Polymer Network Microspheres Research Articles

Formulation and Evaluation of Novel Interpenetrating Polymer Network Microspheres for Controlled Release of Zaleplon

Formulation and Evaluation of Novel Interpenetrating Polymer Network Microspheres for Controlled Release of Zaleplon

FORMULATION AND EVALUATION OF INTERPENETRATING POLYMER NETWORK MICROSPHERES OF INDOMETHACIN BY IONOTROPIC GELATION METHOD

The objective of this research was to formulate interpenetrating polymer network microspheres of indomethacin using sodium alginate and carboxymethyl Delonix regia gum by ionotropic gelation method. Calcium chloride was used in formulations F1 to F4, while calcium chloride along with glutaraldehyde was used in formulations F5 to F8 as a crosslinking agent. Microspheres were characterized by scanning electron microscopy, differential scanning calorimetry and X-ray diffraction studies. The percentage of drug entrapment increased with an increase in the total concentration of polymers. The sizes of microspheres were in the range of 47.2 to 59.5 µm. In vitro dissolution study showed a decrease in the rate of drug release with an increase in the concentration of carboxymethyl Delonix regia gum. Formulations containing glutaraldehyde showed a decrease in the rate of drug release with an increase in the concentration of glutaraldehyde from 2 to 5 % w/v. For all formulations of prepared microspheres, the values of n varied within 0.680 to 0.888, indicated anomalous type diffusive transport.

In vitro and in vivo evaluation of pirfenidone loaded acrylamide grafted pullulan-poly(vinyl alcohol) interpenetrating polymer networks

The aim of present study was to develop controlled release formulation of pirfenidone using acrylamide grafted pullulan. Interpenetrating polymer network (IPN) microspheres were prepared using acrylamide grafted pullulan and PVA utilizing glutaraldehyde assisted water-in-oil emulsion crosslinking method. IPN microspheres were characterized by FTIR, solid state 13C NMR and XRD spectroscopy. In vitro enzymatic degradation study showed 34.30% degradation after 24 h with degradation rate constant of 0.0088 min−1. In vitro biocompatibility test showed no changes in cellular morphology and cell adherence to microspheres, indicating its biocompatible nature. The release exponent value of all formulations was less than 0.45, indicating the release mechanism to be Fickian diffusion. Finally, in vivo pharmacokinetic study showed longer Tmax (1.16 h) and greater AUC value (10037.76 ng h/mL,) as compared to Pirfenex® (Tmax = 0.5 h; AUC = 4310.45 ng h/mL,). The results indicated that the prepared formulation could successfully control the drug release for prolonged time period.

Controlled Release of Salidroside Microspheres Prepared Using a Chitosan and Methylcellulose Interpenetrating Polymer Network

Abstract In this work, salidroside, a functional food agent, was incorporated into novel interpenetrating polymer network microspheres (IPN-Ms) prepared by chitosan (CS) and methylcellulose (MC) for controlled release and stabilization. IPN-Ms were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry and X-ray diffraction. The result indicated that salidroside-loaded IPN-Ms (S-IPN-Ms) are hollow and highly spherical, with a coarse pleated surface and a particle size ranging from 5 to 30 µm. Schiff base formation and the hemiacetal reaction are the primary mechanisms underlying the interpenetrating network cross-linking of IPN-Ms. In S-IPN-Ms, the CS and MC were homogeneously blended, and the salidroside was molecularly and amorphously dispersed. The encapsulation efficiency of the salidroside within the S-IPN-Ms was up to 75.64 %. In the S-IPN-M complex, the release of salidroside by S-IPN-Ms was governed by burst and sustained release, and Fickian diffusion was the primary release mechanism for the entire release process. Thus, controlled release and stabilization of salidroside were achieved through incorporation of salidroside into IPN-Ms prepared by chitosan (CS) and methylcellulose.

Interpenetrating Alginate-Collagen Polymer Network Microspheres for Modular Tissue Engineering.

The lack of vascularization limits the creation of engineered tissue constructs with clinically relevant sizes. We pioneered a bottom-up process (modular tissue engineering) in which constructs with intrinsic vasculature were assembled from endothelialized building blocks. In this study, we prepared an interpenetrating polymer network (IPN) hydrogel from a collagen-alginate blend and evaluated its use as microspheres in modular tissue engineering. Ionotropic gelation of alginate was combined with collagen fibrillogenesis, and the resulting hydrogel was stiffer and had greater resistance to enzymatic degradation relative to that of collagen alone; the viability of embedded mesenchymal stromal cells (adMSC) was unaltered. IPN microspheres were fabricated by a coaxial air-flow technique, and an additional step of collagen coating was required to have human umbilical vein endothelial cells (HUVEC) attach and proliferate. When implanted subcutaneously in SCID/bg mice, adMSC-HUVEC microspheres promoted more blood vessels at day 7 relative to microspheres without adMSC but coated with HUVEC. Perfusion studies confirmed that these vessels were connected to the host vasculature. Fewer vessels were detected in both groups at day 21, but in adMSC-HUVEC explants, more smooth muscle cells had wrapped around vessels, and CLARITY processing of whole explants revealed a restricted leakage of blood. The capacity for rapid gelation and high throughput production are promising features for the use of these microspheres in modular tissue engineering.

Facile preparation of acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network microspheres for controlled oral drug delivery

Hybridization of natural and synthetic polymers is used to improve the physicochemical stability, swelling and drug release pattern of the respective materials in biological condition. In present study, a biodegradable, biocompatible and stable interpenetrating polymer network (IPN) of acrylamide grafted locust bean gum (Am-g-LBG) and poly(vinyl alcohol) (PVA) was developed by emulsion crosslinking method for spatial and temporal drug delivery. The IPN microspheres were prepared with the help of glutaraldehyde as a crosslinker for controlled oral delivery of buflomedil hydrochloride. The formulation parameters were optimized in terms of different gum:PVA ratio, crosslinker amount and drug loading. The microspheres were evaluated for their drug entrapment efficiency, particle size, swelling, SEM, FTIR, NMR, DSC, XRD and in vitro drug release profile. The particles showed well controlled release characteristics and continued to drug release following diffusion controlled release pattern. The drug release was for prolong time without collapsing the particle matrix. Thus, IPN microspheres based delivery system can be a better approach for controlled delivery of highly water soluble drugs like buflomedil hydrochloride.

Ibuprofen microencapsulation within acrylamide-grafted chitosan and methylcellulose interpenetrating polymer network microspheres: Synthesis, characterization, and release studies

This study deals with the development of interpenetrating polymer network (IPN) microspheres of acrylamide (AAm) grafted onto a chitosan (CS) backbone and methylcellulose (MC). Chitosan-graft-polyacrylamide (CS-g-PAAm) was synthesized by cerium (IV) ammonium nitrate-induced free radical graft polymerization. The grafting percentage was found to be 50.58%. The synthesized graft copolymer and MC were used to prepare microspheres by the water-in-oil (w/o) emulsion-crosslinking method, and crosslinked with glutaraldehyde (GA) as drug delivery matrices of ibuprofen (IBU). The release of IBU from microspheres decreased when the amount of CS-g-PAAm in the polymer matrix and amount of crosslinker added were increased, while it increased with the increase of the IBU/polymer ratio.

PH-sensitive interpenetrating polymer network microspheres of poly(vinyl alcohol) and carboxymethyl cellulose for controlled release of the nonsteroidal anti-inflammatory drug ketorolac tromethamine

In this study, we aimed to produce pH-sensitive microspheres for the controlled release of the nonsteroidal anti-inflammatory drug, ketorolac tromethamine (KT). For this purpose, an interpenetrating polymer network (IPN) of microspheres of poly(vinyl alcohol) (PVA)/sodium carboxymethyl cellulose (NaCMC) were prepared, based on different formulations using glutaraldehyde (GA) (0.66 M) and hydrochloric acid (HCl) (3%, v/v). The preparation conditions of the microspheres were optimized by considering the percentage of entrapment efficiency and swelling capacity of the microspheres, and their release data. The effects of PVA and NaCMC ratio on the release of KT for over a period of 6 h, at three pH values (1.2, 6.8, and 7.4), have been discussed.

Development and characterization of pH-sensitive locust bean gum-alginate microspheres for controlled release of ibuprofen

In this study, interpenetrating polymer network (IPN) microspheres, consisting of locust bean gum (LBG) and sodium alginate (NaAlg), were prepared by a water-in-oil (w/o) emulsion cross-linking method using glutaraldehyde (GA) as a cross-linker. These microspheres were loaded with ibuprofen (1BU), a nonsteroidal anti-inflammatory drug. The influence of formulation factors such as the LBG/NaAlg (w/w) ratio, the 1BU loading percentage (w/w), the amount of cross-linker and cross-linking time on the particle size, the entrapment efficiency, and the release of IBU from the microspheres, were evaluated. The IPN microspheres were characterized using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Images of selected microspheres were determined using an optic microscope. The in vitro release of IBU from IPN microspheres was investigated at three pH values (1.2, 6.8 and 7.4) for 2 h, respectively. The release of IBU increased with the increase of the drug loading percentage (w/w), while it decreased with the increasing extent of cross-linking and with the increase in blend ratio (LBG/ NaAlg). The release results indicated that IPN microspheres of LBG and NaAlg exhibited a more controlled release property than plain NaAlg microspheres. IBU release from the microspheres followed either Fickian transport or anomalous transport.

Carboxymethylation of Locust Bean Gum: Application in Interpenetrating Polymer Network Microspheres for Controlled Drug Delivery

For hydrophilic modification, the sodium carboxymethyl ether of locust bean gum was developed by Williamson synthesis using monochloroacetic acid as the etherifying agent. The modification reaction was optimized in terms of concentration of monochloroacetic acid and sodium hydroxide. The modified gum was evaluated for its degree of substitution, elemental analysis, viscosity, swelling, and contact angle. The etherification of locust bean gum was further confirmed by FTIR, 13C NMR, DSC, and XRD techniques. Acute oral toxicity and biodegradability studies showed that the modified gum was safe enough for internal use. This carboxymethylated gum with poly(vinyl alcohol) was utilized to prepare the interpenetrating polymer network microspheres of buflomedil hydrochloride for controlled drug delivery. The microspheres were evaluated for their drug entrapment efficiency, swelling, and particle size. The microspheres were further characterized by FTIR, 13C NMR, and XRD techniques. The in vitro release study of mi...

Preparation and in vitro evaluation of xanthan gum facilitated superabsorbent polymeric microspheres

Interpenetrating polymer network (IPN) hydrogel microspheres of xanthan gum (XG) based superabsorbent polymer (SAP) and poly(vinyl alcohol) (PVA) were prepared by water-in-oil (w/o) emulsion crosslinking method for sustained release of ciprofloxacin hydrochloride (CIPRO). The microspheres were prepared with various ratios of hydrolyzed SAP to PVA and extent of crosslinking density. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. The in vitro drug release study was extensively evaluated depending on the process variables in both acidic and alkaline media. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from the formulations. Based on the results, this study suggest that CIPRO loaded IPN microspheres were suitable for sustained release application.

Synthesis and characterization of Interpenetrating polymer network microspheres of acryl amide grafted Carboxymethylcellulose and Sodium alginate for controlled release of Triprolidine hydrochloride monohydrate

Synthesis and characterization of Interpenetrating polymer network microspheres of acryl amide grafted Carboxymethylcellulose and Sodium alginate for controlled release of Triprolidine hydrochloride monohydrate

Interpenetrating polymer network of locust bean gum-poly (vinyl alcohol) for controlled release drug delivery

A novel interpenetrating polymer network (IPN) microspheres of locust bean gum (LBG) and poly (vinyl alcohol) (PVA) was developed for oral controlled release of buflomedil hydrochloride (BH) by emulsion crosslinking method using glutaraldehyde as crosslinker. The effects of gum–polymer ratio, concentration of crosslinker and internal phase viscosity were evaluated thoroughly. Drug entrapment efficiency, particle size distribution, swelling property and in vitro release characteristics with kinetic modelling of microspheres were evaluated. The microspheres were characterised by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), solid state C13 NMR, X-ray diffraction study (XRD) and differential scanning colorimetry (DSC). The microspheres showed control release property without showing any incompatibility in IPN device. Hence, IPN microspheres of LBG and PVA can be used as a potential carrier for controlled oral delivery of highly water soluble drugs like BH.

Interpenetrating polymer network (IPN) hydrogel microspheres for oral controlled release application

Interpenetrating polymer network (IPN) hydrogel microspheres of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA) were prepared by water-in-oil (w/o) emulsion crosslinking method for oral controlled release delivery of a non-steroidal anti-inflammatory drug, diclofenac sodium (DS). The microspheres were prepared with various ratios of NaCMC to PVA, % drug loading and extent of crosslinking density at a fixed polymer weight. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. The in vitro drug release study was extensively evaluated depending on the process variables in both acid and alkaline media. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from the formulations. Based on the results of this study suggest that DS loaded IPN microspheres were suitable for oral controlled release application.

Stearic Acid-Coated Chitosan-Based Interpenetrating Polymer Network Microspheres: Controlled Release Characteristics

Novel pH-sensitive stearic acid-coated interpenetrating polymer network (IPN) blend microspheres of chitosan and gelatin were prepared by the emulsion cross-linking method using glutaraldehyde for the controlled release (CR) of isoniazid (INH), an antituberculosis drug. Coated as well as uncoated microspheres were developed and characterized by Fourier transform infrared (FTIR) to understand the chemical interactions and formation of the IPN blend structure as well as to confirm successful coating with the stearic acid. X-ray diffraction (XRD) indicated the distribution of INH, while differential scanning calorimetry (DSC) was used for investigating the thermal stability of the IPN blend matrices. Scanning electron microscopy (SEM) was used to distinguish between the morphologies of coated and uncoated microspheres. Coated microspheres were produced in the size range of 52 μm down to 502 nm with encapsulation efficiencies of 65−78%. Equilibrium swelling was studied in pH 1.2 and pH 7.4 buffer media, and the in vitro drug release showed the dependence of drug release on the cross-linking, blend ratio of the IPN matrix as well as stearic acid coating. The variations in the IPN blend ratio and cross-link density controlled the drug release up to 30 h, but the coated microspheres could reduce the burst release in the gastric stomach media, while enhancing in intestinal pH 7.4 media.

Interpenetrating polymer network microspheres of hydroxy propyl methyl cellulose/poly (vinyl alcohol) for control release of ciprofloxacin hydrochloride

Hydroxypropylmethylcellulose and Poly (vinyl alcohol) blend microspheres were prepared by water in oil emulsion method and Ciprofloxacin Hydrochloride (CFHcl) was loaded into the interpenetrating polymer network (IPN) microspheres that are crosslinked with glutaraldehyde (GA). Blend microspheres were characterized using Fourier transform infrared Spectroscopy (FT-IR), Scanning electron microscopy, X-ray diffraction and Differential scanning Calorimetry. FTIR spectra results confirmed crosslinking reaction between –OH groups of Poly (vinyl alcohol) and –CHO groups of glutaraldehyde. Scanning electron micrograph showed the formation of plain, uniform and smooth microspheres. X-ray diffraction and thermal studies of plain and drug loaded microspheres indicates that the drug is dispersed at the molecular level in the IPN matrix. In vitro dissolution experiments were performed in pH 7.4 buffer medium at 35 °C which indicates a sustained and controlled release of ciprofloxacin hydrochloride (CFHcl) from the IPN microspheres up to 10 h.

Novel interpenetrating polymer network microspheres of chitosan and methylcellulose for controlled release of theophylline

Interpenetrating polymer network (IPN) microspheres of chitosan (CS) and methylcellulose (MC) were prepared by emulsion-crosslinking in the presence of glutaraldehyde (GA) as a crosslinker. Theophylline (THP), an antiasthmatic drug was encapsulated into IPN microspheres under varying ratios of MC and CS, % drug loading and amount of GA added. IPNs have shown better mechanical properties than pure CS. Cross-link density of the matrices was significantly affected by the amount of GA and MC. Microspheres were characterized by Fourier transform infrared (FTIR) spectroscopy to assess the formation of IPN structure and to confirm the absence of chemical interactions between drug, polymer and crosslinking agent. Particle size was measured by laser light scattering technique. Microspheres with the average particle sizes ranging from 119 to 318 μm were produced. Differential scanning calorimetry (DSC) and X-ray diffraction (X-RD) studies were performed to understand the crystalline nature of drug after encapsulation into IPN microspheres. Theophylline encapsulation of up to 82% was achieved as measured by UV spectrometer. Equilibrium swelling was performed in distilled water. In vitro release studies were performed in both 0.1 N HCl and pH 7.4 buffer solutions. These data indicated a dependence of drug release on the extent of crosslinking and amount of MC added during the preparation of microspheres. The release was extended up to 12 h and release rates were fitted to an empirical equation to compute the diffusional parameters, which indicated a slight deviation from the Fickian trend for the release of theophylline.