Functionalized crosslinked interpenetrating polymeric network for pH responsive colonic drug delivery

Quince seed mucilage/β-cyclodextrin/Mmt-Na+-co-poly (methacrylate) based pH-sensitive polymeric carriers for controlled delivery of Capecitabine

In current work, quince seed mucilage and β-Cyclodextrin based pH regulated hydrogels were developed using aqueous free radical polymerization to sustain Capecitabine release patterns and to overcome its drawbacks, such as high dose frequency, short half-life, and low bioavailability. Developed networks were subjected to thermal analysis, Fourier transforms infrared spectroscopy, powder x-ray diffraction, elemental analysis, scanning electron microscopy, equilibrium swelling, and in-vitro release investigations to assess the network system's stability, complexation, morphology, and pH responsiveness. Thermally stable pH-responsive cross-linked networks were formed. Nanocomposite hydrogels were prepared by incorporating Capecitabine-containing clay into the swollen hydrogels. All the formulations exhibited equilibrium swelling ranging from 67.98 % to 92.98 % at pH 7.4. Optimum Capecitabine loading (88.17 %) was noted in the case of hydrogels, while it was 74.27 % in nanocomposite hydrogels. Excellent gel content (65.88 %-93.56 %) was noticed among developed formulations. Elemental analysis ensured the successful incorporation of Capecitabine. Nanocomposite hydrogels released 80.02 % longer than hydrogels after 30 h. NC hydrogels had higher t1/2 (10.57 h), AUC (121.52 μg.h/ml), and MRT (18.95 h) than hydrogels in oral pharmacokinetics. These findings imply that the pH-responsive carrier system may improve Capecitabine efficacy and reduce dosing frequency in cancer therapy. Toxicity profiling proved the system's safety, non-toxicity, and biocompatibility.

Novel Natrosol/Pectin-co-poly (acrylate) based pH-responsive polymeric carrier system for controlled delivery of Tapentadol Hydrochloride

Background & Objectives

This study aimed to create a controlled delivery system for Tapentadol Hydrochloride by developing interpenetrating networks (IPNs) of Natrosol-Pectin copolymerized with Acrylic Acid and Methylene bisacrylamide, and to analyze the effects of various ingredients on the physical and chemical characteristics of the IPNs.

Methods

Novel Tapentadol Hydrochloride-loaded Natrosol-Pectin based IPNs were formulated by using the free radical polymerization technique. Co-polymerization of Acrylic Acid (AA) with Natrosol and Pectin was performed by using Methylene bisacrylamide (MBA). Ammonium persulfate (APS) was used as the initiator of crosslinking process. The impact of ingredients i.e. Natrosol, Pectin, MBA, and Acrylic Acid on the gel fraction, porosity, swelling (%), drug loading, and drug release was investigated. FTIR, DSC, TGA, SEM and EDX studies were conducted to confirm the grafting of polymers and to evaluate the thermal stability and surface morphology of the developed IPNs.

Results

Swelling studies exhibited an increase in swelling percentage from 84.27 to 91.17% upon increasing polymer (Natrosol and Pectin) contents. An increase in MBA contents resulted in a decrease in swelling from 85 to 67.63%. Moreover, the swelling was also observed to increase with higher AA contents. Significant drug release was noted at higher pH instead of gastric pH value. Oral toxicological studies revealed the nontoxic and biocompatible nature of Natrosol-Pectin IPNs.

Interpretation & Conclusion

The developed IPNs were found to be an excellent system for the controlled delivery of Tapentadol Hydrochloride.

Aloe vera-Based Polymeric Network: A Promising Approach for Sustained Drug Delivery, Development, Characterization, and In Vitro Evaluation

The present study was conducted to fabricate and characterize mucilage-based polymeric networks of Aloe vera for controlled drug release. Aloe vera mucilage was used to develop a polymeric network via the free-radical polymerization method using potassium persulphate as the initiator, N' N'-Methylene bisacrylamide as the crosslinker, and acrylamide as the monomer. Using varying concentrations of Aloe vera mucilage, crosslinker, and monomer, we developed different formulations. Swelling studies were conducted at pH 1.2 and 7.4. Concentrations of polymer, monomer, and crosslinker were optimized as a function of swelling. Porosity and gel content were calculated for all samples. FTIR, SEM, XRD, TGA, and DSC studies were conducted for the characterization of polymeric networks. Thiocolchicoside was used as a model drug to study the in vitro release in acidic and alkaline pH. Various kinetics models were applied by using a DD solver. Increasing content of monomer and crosslinker swelling, porosity, and drug release decreased while gel content increased. An increase in Aloe vera mucilage concentration promotes swelling, porosity, and drug release of the polymeric network but decreases gel content. The FTIR study confirmed the formation of crosslinked networks. SEM indicated that the polymeric network had a porous structure. DSC and XRD studies indicated the entrapment of drugs inside the polymeric networks in amorphous form. The analytical method was validated according to ICH guidelines in terms of linearity, range, LOD, LOQ, accuracy, precision, and robustness. Analysis of drug release mechanism revealed Fickian behavior of all formulations. All these results indicated that the M1 formulation was considered to be the best polymeric network formulation in terms of sustaining drug release patterns.

Synthesis and characterization of modified bioactive arabinoxylan-psyllium: Evaluation of molecular interactions, physiochemical and biomedical properties

Keeping in view the future prospectus of carbohydrate polymers, present research report is an elaboration, exploration and execution of the research expectancy in area of these polymers by researchers like John F. Kennedy. Herein, molecular interactions and physiochemical properties of modified bioactive arabinoxylan-psyllium have been evaluated for drug delivery applications. Arabinoxylan-psyllium was modified with sulphated and amide copolymers and co-polymers were characterized by SEMs, AFM, FTIR, XRD, solid state ¹³C NMR, TGA-DSC and water absorption studies. The ¹³C-NMR and FTIR confirmed grafted copolymers. The polymer-blood interactions revealed non-thrombogenic nature with thrombose percentage 63.17 ± 5.61 % and polymer-mucous membrane interactions showed detachment force 0.237 ± 0.078Nwith bio-membrane in mucoadhesion test. The pH responsible gels exhibited 44.49 ± 3.12 % inhibitions of free radicals in DPPH assay. The polymer-drug interactions demonstrated sustained diffusion of methotrexate with non-Fickian diffusion and Korsmeyer-Peppas kinetic model. Overall, co-polymeric network structure was found useful in colon specific drug delivery.

Preparation of Ligand Brush Nanocapsules for Robust Self-Controlled Antimicrobial Activity with Low Cytotoxicity at Target pH and Humidity

This study prepared nanocapsules (NCs) with excellent self-controlled antimicrobial activity at pH 6-7 and humidity 45-100%, conditions in which most bacterial and fungal strains thrive. The nanocapsule substrate (NC@SiO2) was 676 nm in diameter, and the ligand-grafted capsule (NC@SiO2-g-MAA) was 888 nm. The large surface area and outer ligand brush of the NCs induced a rapid, self-controlled antibacterial response in the pH and humidity conditions needed for industrial and medical applications. Ligand-brush NCs containing an anionic antimicrobial drug had a rapid release effect because of the repellent electrostatic force and swelling properties of the ligand brushes. Controlled release of the drug was achieved at pH 6 and humidity of 45% and 100%. As many carboxylic acid groups are deprotonated into carboxylic acids at pH 5, the NC@SiO2-g-MAA had a high negative charge density. Carboxylic acid groups are anionized (-COO-) at pH 6 and above and push each other out of the capsule, expanding the outer shell as in a polymer brush to create the release behavior. The surface potential of the NC intermediate (NC@SiO2-MPS) was -23.45 [mV], and the potential of the capsule surface decreased to -36.4 [mV] when the MAA ligand brushes were grafted onto the surface of the capsule intermediate. In an antimicrobial experiment using Escherichia coli, a clear zone of 13-20 mm formed at pH 6, and the E. coli was eradicated completely at pH 6 and pH 7 when the humidity was 100%.

Construction of targeted drug-loaded composite polysaccharide hydrogels and verification of anti-tumor effect in vitro

A targeted composite polysaccharide drug-loaded gel was obtained and characterized. It displayed potent anti-tumor activity via specific binding between the folate in the gel and the folate receptors in the cell membrane.

Formulation and evaluation of interpenetrating polymeric network for controlled drug delivery

Novel Cytarabine-loaded agarose and fenugreek-based hydrogel were formulated via the crosslinking process. Graft copolymerization of methacrylic acid (MAA) on agarose and fenugreek was carried out by using methylene bisacrylamide (MBA) as a crosslinker and potassium persulfate as an initiator. The influence of different formulation ingredients (fenugreek, agarose, MBA, MAA) on swelling index, percentage drug release, and percentage gel content were investigated. It was observed that an increase in the concentration of fenugreek and agarose resulted in an increase in the swelling index (72.45-97.17%). However, an increase in the amount of MBA led to a decrease in the swelling index from 74.23% to 57.74%. A similar result tendency was noted in the case of drug release. FTIR was employed to elucidate effective grafting. The thermal behavior of hydrogel was evaluated through TGA and DSC analysis whereas surface morphology was elucidated through SEM. Release studies were performed at both acidic and basic pH, that is, 1.2 and 7.4. Hence, formulated biocompatible hydrogels proved to be a promising system for the controlled delivery of Cytarabine.