Colon-specific Drug Delivery Research Articles

Formulation and Evaluation of Colon Specific Meloxicam Microcapsules for the Treatment of Arthritis

Objective: The main objective of the current study was to formulate and evaluate meloxicam-loaded microcapsules for colon-specific drug delivery using pH-dependent polymers. The emerging need for developing sustained release NSAIDs to minimize the dosing frequency was the main concern. Consequently, creating an oral sustained release formulation for the treatment of arthritis may be one method to get around this. Methods: Eudragit RS/RL-100 polymers were used in emulsion solvent evaporation processes to create Meloxicam (MLX) microcapsules. Compatibility tests (FTIR), surface morphology by Scanning Electron Microscopy (SEM), yield, drug content, entrapment efficiency, and in vitro dissolution studies were performed on the produced MLX microcapsules. Results: There was no interaction between the polymer and MLX, according to the IR spectra. The microcapsules were spherical in nature, which was confirmed by SEM. Normal frequency distribution MLX microcapsules were produced. The maximum drug entrapment efficiency of 94% was attained. The in vitro performance of MLX microcapsules demonstrated that the polymer concentration influenced sustained release. Furthermore, it was observed that the amount of polymer utilized regulated the release of the drug. Conclusion: Based on the findings, it was concluded that one of the most promising formulation methods for creating colon specific drug delivery systems for the treatment of arthritis is the production of MLX microcapsules.

Indole-3-Acetic Acid Esterified with Waxy, Normal, and High-Amylose Maize Starches: Comparative Study on Colon-Targeted Delivery and Intestinal Health Impact.

Background: Accumulating research suggests that metabolites produced by gut microbiota are essential for maintaining a balanced gut and immune system. Indole-3-acetic acid (IAA), one of tryptophan metabolites from gut microbiota, is critical for gut health through mechanisms such as activating aryl hydrocarbon receptor. Delivery of IAA to colon is beneficial for treatment of gastrointestinal diseases, and one promising strategy is IAA esterified starch, which is digested by gut microbes in colon and releases loaded IAA. Amylose content is a key structural characteristic that controls the physicochemical properties and digestibility of starch. In the current study, IAA was esterified with three typical starches with distinct amylose content to obtain indolyl acetylated waxy maize starch (WMSIAA), indolyl acetylated normal maize starch (NMSIAA), and indolyl acetylated high-amylose maize starch (HAMSIAA). The study comparatively analyzed their respective physicochemical properties, how they behave under in vitro digestion conditions, their ability to deliver IAA directly to the colon, and their effects on the properties of the gut microbiota. The new characteristic peak of 1H NMR at 10.83 ppm, as well as the new characteristic peak of FTIR spectra at 1729 cm-1, represented the successful esterification of IAA on starch backbone. The following in vitro digestion study further revealed that treatment with indolyl acetylation significantly elevated the resistant starch content in the starch samples. In vivo experimental results demonstrated that WMSIAA exhibited the most significant increase in IAA levels in the stomach, whereas HAMSIAA and NMSIAA demonstrated the most remarkable increases in IAA levels in the small intestine and colon, respectively. The elevated IAA levels in the colon are conducive to promoting the growth of beneficial intestinal bacteria and significantly alleviating DSS-induced colitis. This research presents innovative insights and options for the advancement of colon-specific drug delivery systems aimed at preventing and curing gastrointestinal disorders.

Mesalamine-Loaded Microsponges As A Potential Strategy For Colon-Specific Drug Delivery

Mesalamine-Loaded Microsponges As A Potential Strategy For Colon-Specific Drug Delivery

Colon-specific controlled release of oral liposomes for enhanced chemo-immunotherapy against colorectal cancer

A colon-specific drug delivery system has great potential for the oral administration of colorectal cancer. However, the uncontrollable in vivo fate of liposomes makes their effectiveness for colonic location, and intratumoral accumulation remains unsatisfactory. Here, an oral colon-specific drug delivery system (CBS-CS@Lipo/Oxp/MTZ) was constructed by covalently conjugating Clostridium butyricum spores (CBS) with drugs loaded chitosan (CS)-coated liposomes, where the model chemotherapy drug oxaliplatin (Oxp) and anti-anaerobic bacteria agent metronidazole (MTZ) were loaded. Following oral administration, CBS germinated into Clostridium butyricum (CB) and colonized in the colon. Combined with colonic specifically β-glucosidase responsive degrading of CS, dual colon-specific release of liposomes was achieved. And the accumulation of liposomes at the CRC site furtherly increased by 2.68-fold. Simultaneously, the released liposomes penetrated deep tumor tissue via the permeation enhancement effect of CS to kill localized intratumoral bacteria. Collaborating with blocking the translocation of intestinal pathogenic bacteria from lumen to tumor with the gut microbiota modulation of CB, the intratumoral pathogenic bacteria were eliminated fundamentally, blocking their recruitment to immunosuppressive cells. Furtherly, synchronized with lipopolysaccharide (LPS) released from MTZ-induced dead Fusobacterium nucleatum and the tumor-associated antigens produced by Oxp-caused immunogenic dead cells, they jointly enhanced tumor infiltration of CD8+ T cells and reactivated robust antitumor immunity.

Characterization and optimization of colon specific nanosponges immobilized polymeric microbeads formulation for the combined delivery of 5-fluorouracil and curcumin

Introductionand purpose: Site-specific delivery systems are highly advantageous for local cancer treatment as they allow a more significant delivery of the drug to the tumor with minimal systemic side effects. Furthermore, combination therapy is a promising approach that attracts more attention in cancer treatment due to its synergistic effects. In this work, nanosponges immobilized polymeric microbeads for colon-specific delivery systems were developed for a drug combination of 5-fluorouracil and curcumin to treat colorectal cancer. MethodsSodium alginate and low molecular chitosan polymers were used to create microbead-based formulations containing curcumin-encapsulated nanosponges and 5-fluorouracil. To improve curcumin's low solubility, Diphynylacarbonate (DPC) hyper cross-linking of β-CD was used to create curcumin-loaded β-CD nanosponges that further incorporated in the polymeric microbeads along with free 5-fluorouracil. ResultsThe optimized microbeads were spherical with a mean particle size of 1.1 ± 0.05 mm. The produced beads were subsequently coated with a multilayer coating of ethyl cellulose and Eudragit S100 polymers, which functioned as pH-dependent and time-dependent coatings to ensure drug delivery to the colon. The developed formulation (Coated MB5) showed controlled release of the drug and sustained cytotoxic effect. The release profiles of 5-fluorouracil and curcumin from Coated MB5 were best described by zero-order followed by first-order release functions. About 66.4 % of 5-FU and 73.1 % of curcumin were released for 24 h. In vivo roentgenographic evaluation in a rabbit model indicated that the optimized coated microbeads successfully reached the colon 7–9 h after administration. ConclusionsAs a prospective colon-specific drug delivery system, a successful formulation (Coated MB5) was developed for the combined delivery of 5-fluorouracil and curcumin. More in vivo studies are needed to demonstrate the therapeutic efficacy of optimized formulations and their potential to improve colorectal cancer therapy by providing a more targeted administration of combination medicines with fewer undesirable side effects.

Bioengineered carbohydrate polymers for colon-specific drug release: Current trends and future prospects.

The worldwide health burden of colorectal cancer is still substantial, and traditional chemotherapeutic drugs sometimes have poor selectivity, which can result in systemic toxicity and unfavorable side effects. For colon-specific medication delivery, bioengineered carbohydrate polymers have shown promise as carriers. They may enhance treatment effectiveness while minimizing systemic exposure and associated side effects. The unique properties of these manufactured or naturally occurring biopolymers, such as hyaluronic acid, chitosan, alginate, and pectin, enable targeted medicine release. These qualities can be changed to meet the physiological needs of the colon. In the context of colorectal cancer therapy, this article provides a comprehensive overview of current developments and prospective future directions in the field of bioengineered carbohydrate polymer synthesis for colon-specific drug delivery. We discuss numerous techniques for achieving colon-targeted drug release, including enzyme-sensitive polymers, pH-responsive devices, and microbiota-activated processes. To increase tumor selectivity and cellular uptake, we also examine the inclusion of active targeting approaches, such as conjugating specific ligands. Furthermore, we discuss the potential of combination treatment strategies, which use the coadministration of numerous therapeutic medications to target multiple pathways implicated in cancer growth and address drug resistance mechanisms. We address recent biomimetic advances that potentially improve the biocompatibility, cellular uptake, and tumor penetration of carbohydrate polymer-based nanocarriers. These methods involve protein corona engineering and cell membrane coating. Furthermore, we look at the possibility of intelligent and sensitive systems that may adjust their behaviors in response to certain inputs or feedback loops, allowing for precise and regulated drug distribution.

Oral Formulation of 5-Aminosalicylic Acid-Hemoglobin Bio-Adhesive Nanoparticles Enhance Therapeutic Efficiency in Ulcerative Colitis Mice: A Preclinical Evaluation

The oral formulation design for colon-specific drug delivery brings some therapeutic benefits in the ulcerative colitis treatment. We recently reported the specific delivery of hemoglobin nanoparticles-conjugating 5-aminosalicylic acid (5-ASA-HbNPs) to the inflamed site. In the current study, the therapeutic effect of the 5-ASA-HbNPs formulation was confirmed in vivo. This evaluation of 5-ASA-HbNPs not only shows longer colonic retention time due to adhesive properties, also provides full support for it as compared with free 5-ASA. It was considered as a suitable bio-adhesive nanoparticle with mucoadhesive property to pass through the mucus layer and accumulate into the mucosa. In UC model mice, a two-fold decrease in the disease activity indexes and colon weight/length ratios was significantly observed in the group treated with 5-ASA-HbNPs. This group received one percent of the standard dosage of 5-ASA (50 μg/kg), while, a similar result was observed for a significant amount of free 5-ASA (5 mg/kg). Furthermore, microscopic images of histological sections of the extracted colons demonstrated that the 5-ASA-HbNPs and 5-ASA groups displayed instances of inflammatory damage within the colon. However, in comparison to the colitis group, the extent of this damage was relatively moderate, suggesting 5-ASA-HbNPs improved therapeutic efficacy with the lower dosage form.

Colon-targeted 3D-Printed mesalamine tablets: Core-shell design and in vitro/ex-vivo evaluation

ObjectivesThe present study is intended to develop a shell-core tablet using a hot melt extrusion (HME)-based dual-nozzle fused deposition modeling (FDM) three-dimensional (3D) printing approach. The primary objective was to establish a sustained-release colonic drug delivery system and improve mesalamine's permeability by incorporating Vitamin E TPGS as a permeation enhancer. MethodThe study utilized Kollidon® SR for sustained release, L-100, and HPMC HME L100 for the tablet's protective shell. Six filament formulations were tested, and the mechanical properties of the shell filaments, including the three-point bending, Hooke's law, and stiffness, were assessed. Drug release profiles of the tablets were evaluated using the USP-II dissolution apparatus, and permeability characteristics were gauged using the non-everted intestinal sac method. Solutions containing 5% w/v mesalamine and 2.5% w/v Vitamin E TPGS were employed, with pure mesalamine as a control. ResultsOptimal filament ratios were identified as 50:50 for the core and 30:70 for Eudragit L-100 to HPMC HME L100 for the shell. The resulting tablets achieved a prolonged drug release of up to 24 h for the core. They ensured minimal drug release in the upper gastrointestinal tract (∼5% in the first 5 h), effectively targeting the colon. Incorporating Vitamin E TPGS led to a 3.6-fold increase in mesalamine absorption compared to the control, and the addition of Kollidon® SR notably improved the flow properties of Mesalamine powder. ConclusionIn conclusion, this innovative approach has the potential to achieve a colon-specific drug delivery system.

Synthesis, characterization, and application of honey stabilized inulin nanoparticles as colon targeting drug delivery carrier

Inulin (INU) is a versatile natural polysaccharide primarily derived from chicory roots. INU possesses the unique quality of evading digestion or fermentation in the early stages of the human digestive tract, instead reaching the lower colon directly. Exploiting on this distinctive attribute, INU finds application in the creation of targeted carrier systems for delivering drugs tailored to colon-related diseases. This study presents a novel method for synthesizing highly stable and non-aggregatory inulin nanoparticles (INU NPs) by ionotropic gelation method, using calcium chloride as crosslinker and natural honey as a stabilizing agent. Different formulation and process parameters were optimized for the synthesis of monodispersed INU NPs. These INU NPs efficiently encapsulated a hydrophilic drug irinotecan hydrochloride trihydrate (IHT) and drug loaded formulation (IINPs) demonstrated excellent colloidal and storage stabilities. Notably, these IINPs exhibited pH-dependent drug release, suggesting potential for colon-specific drug delivery. Anticancer activity of the NPs was found significantly higher in comparison to IHT through cytotoxicity and apoptosis studies against human colorectal carcinoma cells. Overall, this study revealed that the INU NPs synthesized by ionotropic gelation will be an efficient nanocarrier system for colon-targeted drug delivery due to their exceptional biocompatibility and stability in stomach and upper intestinal conditions.

Smart mucoadhesive 3-D network hydrogels for use in localized impregnated anticancer drug delivery

Recently, bioactive dietary fibers (DFs) have been explored for various benefits to human health because of their therapeutic activities. Role of DF psyllium (arabinoxylan (Ax)) has been established for curing colon cancer. Herein, methotrexate (MXT), an anti-neoplastic agent, was impregnated into network hydrogels developed from DF psyllium, through graft copolymerization reactions for its sustained colon-specific drug delivery (DD). Copolymers were characterized through SEM, AFM, FTIR, C13-NMR and TGA analysis. Smart hydrogels demonstrated antioxidant (39.40 ± 0.78% free radical scavenging in the DPPH assay), biocompatible (1.16 ± 0.22% hemolysis value in blood-polymer interactions), and mucoadhesive (7.0 ± 0.1 mN detachment force from the mucous membrane) properties. Sustained diffusion of MXT in colonic conditions occurred with a Fickian mechanism, and release profile obeyed the Korsmeyer-Peppas kinetic model. Overall, findings suggested the suitability of DF psyllium-based DD carriers for colon with enhanced potential.

Preparation and in-vitro evaluation of single and bi-layered beeswax-based microparticles for colon-specific delivery of mesalamine

Beeswax is selected as a natural coating material for the development of new colon specific drug delivery systems charged by mesalamine. In a first step, beeswax microparticles are prepared using hot-melt process of microencapsulation where drug:beeswax ratio, stirring speed, emulsifier concentration and pH of external phase are varied for the optimization of the drug entrapment and microparticles? morphology. The effect of the nature of the emulsifier is also discussed by studying the hydrophilic?lipophilic balance (HLB) value. In a second step, to obtain delayed delivery systems, bi-layered microspheres are elaborated by the process of emulsion?solvent evaporation using ethylcellulose or cellulose acetate butyrate as outer enteric coating layer. All formulations are characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and optical microscopy. The drug release is established in simulated gastric, small bowel and colon liquids and the release mechanism is discussed by applying the Korsmeyer?Peppas model.

Formulation and Evaluation of Budesonide-loaded Nanosponges for Colon-specific Drug Delivery Systems

Formulation and Evaluation of Budesonide-loaded Nanosponges for Colon-specific Drug Delivery Systems

Characteristics of Interpolyelectrolyte Complexes Based on Different Types of Pectin with Eudragit® EPO as Novel Carriers for Colon-Specific Drug Delivery.

Given that pectin is a well-known substance used for drug delivery, we aimed to obtain and further examine the efficacy of interpolyelectrolyte complexes based on citrus or apple pectin and the Eudragit® EPO for using these carriers in oral drug delivery. To characterize the physicochemical properties of these compounds, turbidity, gravimetry, viscosity, elementary analysis, FTIR spectroscopy, and DSC analysis were utilized. Diffusion transport characteristics were evaluated to assess the swelling ability of the matrices and the release of diclofenac sodium. To examine the release parameters, mathematical modeling was performed by using the Korsmayer-Peppas and Logistic equations as well. During the turbidity study, stoichiometry compositions were selected for the developed IPECs EPO/PecA and EPO/PecC at pH values = 4.0, 5.0, 6.0, and 7.0. The FTIR spectra of the complexes were characterized by an increase in the intensity of the bands at 1610 cm-1 and 1400 cm-1. According to the DSC analysis, IPEC has a certain Tg = 57.3 °C. The highest release rates were obtained for IPEC EPO/PecC_1 and EPO/PecC_4. The mechanism of drug transport from the matrices IPEC EPO/PecC, IPEC EPO/PecA_3, and EPO/PecA_4 can be characterized as Super Case II. Anomalous release (non-Fickian release) is typical for IPEC EPO/PecA_1 and EPO/PecA_2. Thus, the resulting systems can be further used for the effective delivery of the drugs to the colon.

Current trends and future perspectives of natural polymer loaded nanoparticle based drug delivery system for the management of inflammatory bowel disease

Targeting the drug delivery system is very tough nowadays due to premature drug release at the upper GIT tract and altered pH conditions. Colon-specific drug delivery systems can overcome that problem using different polymer combinations. A nanoparticulate drug delivery system is the prominent dosage form that impacts the bioavailability and requires a low dose to excrete the therapeutic efficacy. All nanoscience and nanotechnology are applications of Nanometrology, the science of measurements at the nanoscale. NPDDSs were primarily developed to combine the colloidal stability of solid particle suspensions in biological fluids and the solubilizing properties of liquids. An ideal drug-delivery system possesses two elements: the ability to target and control the drug release. Colloidal drug carriers offer a number of potential advantages as delivery systems, such as better bioavailability for poorly soluble drugs. Researchers have created various sophisticated and multifunctional nanocarrier systems that can transport pharmaceuticals in a targeted, sustained, and regulated manner to provide therapeutic medications that are safer and more effective, particularly to ulcerative colitis. These innovative technologies are improving the pharmacokinetic profile of pharmaceuticals, increasing their systemic circulation, and decreasing the frequency of pharmacological side effects. The review focuses on the current trend and future perspectives of natural polymer-based-loaded nanoparticle-based drug delivery systems for the management of inflammatory bowel disease.

Development of 3D-Printed Bicompartmental Devices by Dual-Nozzle Fused Deposition Modeling (FDM) for Colon-Specific Drug Delivery.

Dual-nozzle fused deposition modeling (FDM) is a 3D printing technique that allows for the simultaneous printing of two polymeric filaments and the design of complex geometries. Hence, hybrid formulations and structurally different sections can be combined into the same dosage form to achieve customized drug release kinetics. The objective of this study was to develop a novel bicompartmental device by dual-nozzle FDM for colon-specific drug delivery. Hydroxypropylmethylcellulose acetate succinate (HPMCAS) and polyvinyl alcohol (PVA) were selected as matrix-forming polymers of the outer pH-dependent and the inner water-soluble compartments, respectively. 5-Aminosalicylic acid (5-ASA) was selected as the model drug. Drug-free HPMCAS and drug-loaded PVA filaments suitable for FDM were extruded, and their properties were assessed by thermal, X-ray diffraction, microscopy, and texture analysis techniques. 5-ASA (20% w/w) remained mostly crystalline in the PVA matrix. Filaments were successfully printed into bicompartmental devices combining an outer cylindrical compartment and an inner spiral-shaped compartment that communicates with the external media through an opening. Scanning electron microscopy and X-ray tomography analysis were performed to guarantee the quality of the 3D-printed devices. In vitro drug release tests demonstrated a pH-responsive biphasic release pattern: a slow and sustained release period (pH values of 1.2 and 6.8) controlled by drug diffusion followed by a faster drug release phase (pH 7.4) governed by polymer relaxation/erosion. Overall, this research demonstrates the feasibility of the dual-nozzle FDM technique to obtain an innovative 3D-printed bicompartmental device for targeting 5-ASA to the colon.

Comparison of 5-ASA layered or matrix pellets coated with a combination of ethylcellulose and eudragits L and s in the treatment of ulcerative colitis in rats

The aim of this study was to evaluate and optimize the combination of time and pH-dependent polymers as a single coating for the design of the colon-specific drug delivery system of 5-aminosalicylic acid (5-ASA) pellets. 5-ASA matrix pellets with a 70% drug load were prepared by the extrusion-spheronization method. The optimal coating formula which included Eudragit S (ES) + Eudragit L (EL) + Ethylcellulose (EC) was predicted for the targeted drug delivery to the colonic area by a 32 factorial design. The ratio of ES:EL:EC and coating level were considered as independent variables while the responses were the release of less than 10% of the drug within 2 h (Y1), the release of 60–70% within 10 h at pH 6.8 (Y2) and lag time of less than 1 h at pH 7.2 (Y3). Also, 5-ASA layered pellets were prepared by the powder layering of 5-ASA on nonpareils (0.4–0.6 mm) in a fluidized bed coater and then coated with the same optimum coating composition. The coated 5-ASA layered or matrix pellets were tested in a rat model of ulcerative colitis (UC) and compared with the commercial form of 5-ASA pellets (Pentasa®). The ratio of ES:EL:EC of 33:52:15 w/w at a coating level of 7% was discovered as the optimum coating for the delivery of 5-ASA matrix pellets to the colon. The coated 5-ASA pellets were spherical with uniform coating as shown by SEM and met all of our release criteria as predicted. In-vivo studies demonstrated that the optimum 5-ASA layered or matrix pellets had superior anti-inflammatory activities than Pentasa® in terms of colitis activity index (CAI), colon damage score (CDS), colon/body weight ratio and colon’s tissue enzymes of glutathione (GSH) and malondialdehyde (MDA). The optimum coating formulation showed a high potential for colonic delivery of 5-ASA layered or matrix pellets and triggered drug release based on pH and time.

Fabrication of acacia gum grafted copolymeric network hydrogel for biomedical applications

Keeping in view therapeutic role of gum polysaccharides and to explore advancements in research expectancy in area of gum for future research for development of new materials for biomedical applications, in present research, acacia gum was grafted with poly(acrylamide) [poly(AAm)] and poly(2-arylamido-2-methylpropanesulfonic acid) poly(AMPSA) to design hydrogels by copolymerization for use in drug delivery of levofloxacin antibiotic drug. These co-polymers were characterized by SEMs, AFM, FTIR, 13C NMR, XRD and TGA. The SEM indicated uneven surface due to grafting and AFM confirmed the surface roughness for better mucoadhesion. The prominent peaks at 178.871 ppm and 52.180 ppm indicated the incorporation of the AAM and AMPSA due to CO and C–S into copolymer by grafting reaction. XRD indicated the amorphous region and TGA reflected three stages thermal decomposition. The results reflected slow release of drug due to supra-molecular interactions between drug and copolymers and diffusion of drug occurred with non-Fickian mechanism from network hydrogels with first order kinetic release model. The copolymeric material showed radical scavenging activity was 26.12 ± 2.23% in DPPH assay and 3.42 ± 0.396% hemolytic index values. The network copolymers also showed 0.281 ± 0.093 N peak detachment force from mucoadhesive test. The results of biomedical assay inference the non-hemolytic behavior with antioxidant and mucoadhesive nature of the network copolymers. These results signified the suitability of the polymeric materials for colon specific drug delivery.

Development of the new pH-driven carrier from alginate/carboxymethyl starch bio-coated co-drugs@COF-OH for controlled and concomitant colon cancer treatment

To develop a new more efficient colon cancer treatment bio-vehicle, in frontier research, for the first time, an attempt has been made to design a unique colon-targeted bio-carrier containing polysaccharides along with nanoporous materials. So, at first, an imine-based covalent organic framework (COF-OH) with respectively an average pore diameter and surface area at 8.5058 nm and 208.29 m2·g−1 was fabricated. In the next step, about 41.68 % and 95.8 % of 5-fluorouracil (5-Fu) and curcumin (CUR) respectively were loaded on COF-OH, and 5-Fu + CUR@COF-OH was achieved. Due to the higher rate of drug releases in simulated stomach media, 5-Fu + CUR@COF-OH was coated with a mixture of alginate (Alg) and carboxymethyl starch (CMS) via the ionic crosslinking (Alg/CMS@(5-Fu + CUR@COF-OH)). Findings displayed that the use of polysaccharide coat reduce the drug releases in simulated gastric and improved it in simulated intestinal and colonic fluids. The beads swelled about 93.33 % under simulated gastrointestinal conditions, but this value was found higher in the simulated colonic environment and reached 326.67 %. The hemolysis rate lower than 5 %, as well as the cell viability higher than 80 %, were the main showing signs of system biocompatibility. Altogether, the results of the preliminary investigations can highlight the potential of the Alg/CMS@(5-Fu + CUR@COF-OH) for colon-specific drug delivery.

Development of Novel pH-Sensitive Eudragit Coated Beads Containing Curcumin-Mesalamine Combination for Colon-Specific Drug Delivery.

This research aims to develop a drug delivery system that effectively treats colitis while administering curcumin/mesalamine by coating alginate/chitosan beads with Eudragit® S-100 to target the colon. Beads were tested to determine their physicochemical characteristics. Coating with Eudragit® S-100 prevents drug release at a pH of less than 7; this was demonstrated by in-vitro release conducted in a medium with gradually varying pH to mimic circumstances in various regions of the gastrointestinal tract. This study examined the efficacy of the coated beads in treating acetic acid-induced colitis in rats. Results showed that spherical beads were formed with an average diameter of 1.6-2.8 mm, and the obtained swelling ranged from 409.80% to 890.19%. The calculated entrapment efficiency ranged from 87.49% to 97.89%. The optimized formula F13 (which was composed of mesalamine-curcumin active ingredients, Sodium alginate as a gelling agent, chitosan as a controlled release agent, CaCl2 as a crosslinking agent, and Eudragit S-100 as a pH-sensitive coating agent) demonstrated the best entrapment efficiency (97.89% ± 1.66), swelling (890.19% ± 60.1), and bead size (2.7 ± 0.62 mm). In formulation #13, which was coated with Eudragit S 100, curcumin (6.01 ± 0.04%) and mesalamine (8.64 ± 0.7%), were released after 2 h at pH 1.2; 6.36 ± 0.11% and 10.45 ± 1.52% of curcumin and mesalamine, respectively, were then released after 4 h and at pH 6.8. Meanwhile, at pH 7.4, after 24 h, approximately 85.34 ± 2.3% (curcumin) and 91.5 ± 1.2% (mesalamine) were released. Formula #13 significantly reduced the colitis, and this suggests that the developed hydrogel beads can be used for delivering curcumin-mesalamine combinations to treat ulcerative colitis after adequate research.

A Review on Colon Targeted Drug Delivery System

Colon-specific drug delivery systems (CDDS) are advantageous for the treatment of a range of local diseases such as ulcerative colitis, Crohn’s disease, irritable bowel syndrome, chronic pancreatitis, and colonic cancer. Colon targeted drug delivery system can be utilized to deliver protein and peptide drugs as they that are known to degrade in the extreme gastric pH. These approaches involve the use of formulation components that interact with one or more aspects of gastrointestinal (GI) physiology, such as the variation in the pH along the GI tract, the occurrence of colonic microflora, and enzymes, to attain colon targeting. This article highlights the advantages, limitations and factors influencing colon-specific drug delivery. Further, the review gives information of various conventional, as well as relatively newer formulation approaches presently being utilized for the improvement of CDDS.