Development and In Vitro Characterization of Capecitabine-Loaded Alginate–Pectinate–Chitosan Beads for Colon Targeting

Engineering Thermo/pH-Responsive Lactoferrin Nanostructured Microbeads for Oral Targeting of Colorectal Cancer

AIM

Colorectal cancer is an extremely aggressive form of cancer that often leads to death. Lactoferrin shows potential for targeting and treating colorectal cancer; however, oral delivery faces hurdles hampering clinical applications. We engineered dual-responsive lactoferrin nanostructured microbeads to overcome delivery hurdles and enhance drug targeting.

METHODS

The hydrophobic drug mesalazine (MSZ) was coupled to lactoferrin to form amphiphilic conjugate nanoparticles, dispersed in water. The lipid-soluble polyphenolic drug resveratrol (RSV) was then encapsulated into the hydrophobic core of LF-MSZ nanoparticles. To impart thermoresponsive properties, the dual-payload NPs were coupled with a PNIPAAm shell; finally, to further endow the nanoparticles with gastrointestinal resistance and pH responsiveness, the nanoparticles were microencapsulated into ionically cross-linked pectin-alginate beads.

RESULTS

The nanoparticles showed enhanced internalization and cytotoxicity against HCT colon cancer cells via LF-receptor-mediated endocytosis. Thermal triggering and tuned release were conferred by the temperature-sensitive polymer. The coatings protected the drugs from degradation. Orally delivered microbeads significantly reduced tumor burden in a mouse colon cancer model, lowering carcinoembryonic antigen and elevating antioxidant enzymes. Apoptotic pathways were stimulated, indicated by heightened Bax/Bcl2 ratio and caspase-3/9 expression.

CONCLUSION

Overall, we propose the innovative lactoferrin nanostructured microbeads as a paradigm shift in oral colorectal cancer therapeutics.

Mimosa/quince seed mucilage-co-poly (methacrylate) hydrogels for controlled delivery of capecitabine: Simulation studies, characterization and toxicological evaluation

This research focused on developing pH-regulated intelligent networks using quince and mimosa seed mucilage through aqueous polymerization to sustain Capecitabine release while overcoming issues like short half-life, high dosing frequency, and low bioavailability. The resulting MSM/QSM-co-poly(MAA) hydrogel was evaluated for several parameters, including complex structure formation, stability, pH sensitivity, morphology, and elemental composition. FTIR, DSC, and TGA analyses confirmed the formation of a stable, complex cross-linked network, demonstrating excellent stability at elevated temperatures. SEM analysis revealed the hydrogels' smooth, fine texture with porous surfaces. PXRD and EDX results indicated the amorphous dispersion of Capecitabine within the network. The QMM9 formulation achieved an optimal Capecitabine loading of 87.17 %. The gel content of the developed formulations ranged from 65.21 % to 90.23 %. All formulations exhibited excellent swelling behavior, with ratios between 65.91 % and 91.93 % at alkaline pH. In vitro dissolution studies indicated that up to 98 % of Capecitabine was released after 24 h at pH 7.4, demonstrating the potential for sustained release. Furthermore, toxicological evaluation in healthy rabbits confirmed the system's safety, non-toxicity, and biocompatibility.

Development and evaluation of a pH-responsive Mimosa pudica seed mucilage/β- cyclodextrin-co-poly(methacrylate) hydrogel for controlled drug delivery: In vitro and in vivo assessment

In this comprehensive investigation, a novel pH-responsive hydrogel system comprising mimosa seed mucilage (MSM), β-cyclodextrin (β-CD), and methacrylic acid (MAA) was developed via free radical polymerization technique to promote controlled drug delivery. The hydrogel synthesis involved strategic variations in polymer, monomer, and crosslinker content in fine-tuning its drug-release properties. The resultant hydrogel exhibited remarkable pH sensitivity, selectively liberating the model drug (Capecitabine = CAP) under basic conditions while significantly reducing release in an acidic environment. Morphological, thermal, and structural analyses proved that CAP has a porous texture, high stability, and an amorphous nature. In vitro drug release experiments showcased a sustained and controlled release profile. Optimum release (85.33 %) results were recorded over 24 h at pH 7.4 in the case of MMB9. Pharmacokinetic evaluation in healthy male rabbits confirmed bioavailability enhancement and sustained release capabilities. Furthermore, rigorous toxicity evaluations and histopathological analyses ensured the safety and biocompatibility of the hydrogel. This pH-triggered drug delivery system can be a promising carrier system for drugs involving frequent administrations.

Colorectal cancer management: Strategies in drug delivery

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer leading to death worldwide following breast and lung cancer with the incidence rate of 10%. The treatment comprises of surgery, radiation, and ablation therapy depending upon the stage of cancer.

AREAS COVERED

The review focuses on various drug delivery strategies explored to circumvent the major constraints associated with the conventional drug delivery systems- poor bioavailability, intra- and inter individual variability, exposure of normal cells to antineoplastic agents, and presence of efflux pump. All these attributes impact the effective delivery of chemotherapeutic agents at the tumor site. The various target specific drug delivery systems developed for colorectal cancer include pH dependent, microbiologically triggered, time dependent, magnetically driven, pressure dependent, prodrug/polysaccharide based, osmotic and ligand mediated systems. This review enumerates novel target specific approaches developed and investigated for potential utility in CRC therapeutics.

EXPERT OPINION

The limitations of conventional delivery systems can be overcome by development of colon-specific targeted drug delivery systems that overcome the obstacles of nonspecific biodistribution, drug resistance and unwanted adverse effects of conventional drug delivery systems. In addition, nanotechnology approaches help to increase drug solubility, bioavailability, reduce side effects and provide superior drug response in CRC.

Electrosprayed chitosan-coated alginate-pectin beads as potential system for colon-targeted delivery of ellagic acid

BACKGROUND

Ellagic acid (EA), a potent dietary antioxidant, has limited bioavailability owing to its rapid absorption in the stomach and small intestine, and EA is transformed to more bioavailable compounds - urolithins - in the colon. An encapsulation system that sustains the release of EA in the gastrointestinal system and delivers more EA into the colon could improve the oral bioavailability of EA. Electrosprayed EA-loaded alginate-pectin beads were produced and coated with low- (LC) and high-molecular-weight chitosan (HC). The EA release from uncoated and coated beads under simulated gastrointestinal conditions was evaluated. The samples were characterized by particle size, gel strength, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analysis.

RESULTS

The encapsulation efficiency (EE%) of EA ranged from 49.53% to 69.85% for uncoated beads, which was elevated up to 86.50% by coating, and LC coating provided higher EE%. Pectin addition to alginate and chitosan coating reduced the gel strength and changed the size depending on the molecular weight of chitosan. SEM images of pectin-added beads showed fewer cracks but more wrinkles, and chitosan coating presented more aggregated surfaces. The ionic interaction of alginate-pectin-chitosan and the entrapment of EA were confirmed by FTIR. In the gastric medium, EA release was very low from uncoated beads (15.2-19.8%), and totally restricted by chitosan coating. In the intestinal stage, EA release from LC-coated alginate-pectin beads was only 18%, and it was between 55% and 65% for uncoated or HC-coated counterparts.

CONCLUSION

The LC-coated alginate-pectin beads could be further explored as a potential system for colon-targeted delivery of EA. © 2021 Society of Chemical Industry.

Investigation on Potential of Chitosan Nanoparticles for Oral Bioavailability Enhancement of Risedronate Sodium

Risedronate sodium (RS) is used in osteoporosis for bone reabsorption. It is a BCS class III drug having poor oral bioavailability (<0.63%) due to low permeability. In the present study, RS-loaded chitosan nanoparticles were developed to increase oral bioavailability and evaluated for various parameters. The DSC study indicated compatibility of RS with excipients in their physical mixture. The nanoparticles were prepared by ionotropic gelation technique and lyophilized. The optimized batch (RS-CNs) was found to have particles of size 268.7 nm and zeta potential of 24.9 mV. The TEM image of RS-CNs revealed discrete spherical particles. Angle of repose of 27.02 indicates good flow property of nanoparticles. FT-IR spectra of RS-CNs showed characteristic peaks of RS indicating compatibility of RS with the excipients. The mucin binding efficiency of RS-CNs was obtained as 63.42%. The in vitro release study of RS indicated controlled delivery from RS-CNs over 22 h. The release mechanism was found to be diffusion- and erosion-controlled release. Ex vivo study using rat intestine revealed faster permeation of 32.78% in 6 h from RS-CNs compared to plain drug solution. In vivo pharmacokinetic study in rats showed increased C_max (1.8 fold) from RS-CNs compared to marketed formulation. The relative bioavailability of 193% from RS-CNs indicated significant enhancement in bioavailability upon nanoparticle formulation. The RS-CNs were found to be stable at room and refrigerated conditions. In conclusion, developed RS-loaded chitosan nanoparticles seem to be a promising approach to increase oral bioavailability and can avoid upper GI tract side effects.

QbD enabled optimization of solvent shifting method for fabrication of PLGA-based nanoparticles for promising delivery of Capecitabine for antitumor activity

The key objective of the current research was to fabricate and optimize Capecitabine (Cap)-loaded [poly(lactic-co-glycolic acid)] PLGA-based nanoparticles (NPs) by enabling quality by design (QbD) approach for enhancing antitumor activity by promising delivery of the drug at the colonic site. The current research was based on fabricating PLGA-based nanoparticles along with Eudragit S100 as enteric polymer employing solvent shifting method followed by optimization using QbD approach. This approach was found to be useful for understanding the multiple factors and their interaction influencing the product by utilizing Design of Experiment (DOE). Box-Behnken design (BBD) was adopted to achieve the required critical quality attributes (CQAs), i.e., minimizing particle size, maximizing entrapment efficiency, and minimizing PDI value. The optimized nanoparticles were lyophilized and characterized by FT-IR, DSC, TEM, DLS, MTT assay using HT-29 cell lines, and in vivo pharmacokinetic studies. The optimized PLGA-based nanoparticles were found to possess average particle size, PDI, zeta potential, and entrapment efficiency of 195 nm, 0.214, -6.65 mV, and 65%, respectively. TEM analysis revealed the spherical nature of nanoparticles. The FT-IR and DSC studies revealed no interaction. The bioavailability of Cap-loaded nanoparticles was found to be two fold increased than the pure drug, and also, it exhibited significantly more cytotoxic to tumor cells as compared to pure drug as confirmed by MTT assay. The optimized PLGA-based nanoparticles found to possess enhanced bioavailability and significantly more cytotoxic potential as compared to pure drug.

Development of biodegradable thin films for efficient, specific and controlled delivery of capecitabine

Cancer is the leading cause of death worldwide. Capecitabine (CP) shows severe side effects because of early metabolism in stomach that affects the normal cells and organs, particularly liver and stomach. In this scope, we report the biocompatible, nontoxic polymeric thin films loaded with anti-cancer drug, CP for target specific, sublingual delivery of CP. Chitosan (CS) and polyvinyl alcohol (PVA) were used as biodegradable polymers alongwith glutaraldehyde (GLA) cross linker. CP-loaded thin films (TFCP1-TFCP5) were fabricated by solvent casting method. The results of Fourier transform infrared spectroscopy confirmed the presence of CP and polymers (CS and PVA) with GLA which binds through hydrogen bonding, and compatibility of drug with different excipients. Thermogravemetric analysis showed that the thin films are highly stable while differential scanning calorimeter thermograms confirmed the complete miscibility/entrapment of CP within PVA/CS thin film matrix. X-ray diffraction patterns revealed the molecular ineractions between CP and polymer matrix. High degree of swelling index of thin films at pH 7.4 was observed in comparison to pH 5.5. CP release studies in acetate (pH 5.5) and phosphate buffer (pH 7.4) showed that the thin films swell and result in drug diffusion faster in phosphate buffer through diffusion governed by Higuchi's model. Cytotoxicity results displayed that CPTFs killed MCF-7 and T47D (human breast adenocarcinoma) cells more effectively as compared to CP alone. The results of adhesion assay also showed that the PVA and CS both are safe and biocompatible. TFCP1 and TFCP3 thin films efficiently induced the apoptosis as compared to CP alone. The improved ability of TFCP1 and TFCP3 to induce cytotoxicity in MCF-7 cells reflects the potential of these thin films for targeted drug delivery. The CPTFs were stable for 4 months at 4 °C/60% ± 2%RH and 25 °C/70% ± 2%RH. In conclusion, the thin film formulations showed target specific controlled and burst release properties and thus could prove to be effective for human breast cancer treatment.

Formulation, development and in vitro characterization of modified release tablets of capecitabine

Objective: The main aim of this research work was to develop and evaluate cost effective modified release tablets of Capecitabine (CAP) without utilizing coating techniques.Methods: The tablets were prepared by non-aqueous wet granulation method. Hydroxypropyl cellulose (HPC) was used as an extended release matrix former and sodium alginate (SA) was used as sustained release agent due to its gel forming ability. 3² full factorial design was used to study the effect of the independent variables i.e. HPC and SA on dependent variables, in vitro drug release and swelling index. The physiochemical properties of the drug were analyzed by ultraviolet (UV), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and powder X-ray diffraction (P-XRD). The formulated tablets were evaluated for hardness, thickness, weight variation, content uniformity, swelling index, and in vitro drug release study.Results: The FTIR and DSC studies confirmed that there was no any interaction between drug, polymers and excipients. Also from DSC and P-XRD studies it was clear that the crystalline nature of CAP was remain unchanged in the optimized formulation tablet. Formulation F8 retarded the drug release up to 24 h with the optimum concentration of the both the polymers.Conclusion: We have successfully developed the modified release tablets of CAP with the combination of diffusion and erosion controlled type of drug release mechanism.