Advances in Pharmaceutical Strategies Enhancing the Efficiencies of Oral Colon-Targeted Delivery Systems in Inflammatory Bowel Disease

Investigating the therapeutic promise of drug-repurposed-loaded nanocarriers: A pioneering strategy in advancing colorectal cancer treatment

Globally, colorectal cancer is a major health problem that ranks in third place in terms of occurrence and second in terms of mortality worldwide. New cases increase annually, with the absence of effective therapies, especially for metastatic colorectal cancer, emphasizing the need for novel therapeutic approaches. Although conventional treatments are commonly used in oncotherapy, their success rate is low, which leads to the exploration of novel technologies. Recent efforts have focused on developing safe and efficient cancer nanocarriers. With their nanoscale properties, nanocarriers have the potential to utilize internal metabolic modifications amid cancer and healthy cells. Drug repurposing is an emerging strategy in cancer management as it is a faster, cheaper, and safer method than conventional drug development. However, most repurposed drugs are characterized by low-key pharmacokinetic characteristics, such as poor aqueous solubility, permeability, retention, and bioavailability. Nanoparticles formulations and delivery have expanded over the past few decades, creating opportunities for drug repurposing and promises as an advanced cancer modality. This review provides a concise and updated overview of colorectal cancer treatment regimens and their therapeutic limitations. Furthermore, the chemotherapeutic effect of various FDA-approved medications, including statins, non-steroidal anti-inflammatory drugs, antidiabetic and anthelmintic agents, and their significance in colorectal cancer management. Along with the role of various nanocarrier systems in achieving the desired therapeutic outcomes of employing these redefined drugs.

Zein: Potential biopolymer in inflammatory bowel diseases

Effectively managing inflammatory bowel disease (IBD) poses difficulties due to its persistent nature and unpredictable episodes of exacerbation. There is encouraging evidence that personalized medication delivery systems can improve therapy efficacy while reducing the negative effects of standard medicines. Zein, a protein produced from corn, has garnered interest as a possible means of delivering drugs for the treatment of IBD. This review delves into Zein-based drug delivery systems, showcasing its biodegradability, controlled release capabilities, and biocompatibility. Studies have shown that Zein-based nanoparticles, microcarriers, and core-shell microparticles have the capacity to increase medication stability, enhance targeting in the intestines, and decrease toxicity in animal models of IBD. The review highlights the promise of Zein in personalized therapy for IBD and urges more study to enhance its clinical use.

Nanomedicine for colon-targeted drug delivery: strategies focusing on inflammatory bowel disease and colon cancer

The nanostructured drug-delivery systems for colon-targeted drug delivery are a promising field of research for localized diseases particularly influencing the colonic region, in other words, ulcerative colitis, Crohn's disease, and colorectal cancer. There are various drug-delivery approaches designed for effective colonic disease treatment, including stimulus-based formulations (enzyme-triggered systems, pH-sensitive systems) and magnetically driven drug-delivery systems. In addition, targeted drug delivery by means of overexpressed receptors also offers site specificity and reduces drug resistance. It also covers GI tract-triggered emulsifying systems, nontoxic plant-derived nanoformulations as advanced drug-delivery techniques as well as nanotechnology-based clinical trials toward colonic diseases. This review gives insight into advancements in colon-targeted drug delivery to meet site specificity or targeted drug-delivery requirements.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Fabrication and optimization of itraconazole-loaded zein-based nanoparticles in coated capsules as a promising colon-targeting approach pursuing opportunistic fungal infections

Itraconazole (ITZ), a broad-spectrum antifungal drug, was formulated into colon-targeting system aiming to treat opportunistic colonic fungal infections that commonly infect chronic inflammatory bowel diseases (IBD) patients due to immunosuppressive therapy. Antisolvent precipitation technique was employed to formulate ITZ-loaded zein nanoparticles (ITZ-ZNPs) using various zein: drug and aqueous:organic phase ratios. Central composite face-centered design (CCFD) was used for statistical analysis and optimization. The optimized formulation was composed of 5.5:1 zein:drug ratio and 9.5:1 aqueous:organic phase ratio with its observed particle size, polydispersity index, zeta potential, and entrapment efficiency of 208 ± 4.29 nm, 0.35 ± 0.04, 35.7 ± 1.65 mV, and 66.78 ± 3.89%, respectively. ITZ-ZNPs were imaged by TEM that revealed spherical core-shell structure, and DSC proved ITZ transformation from crystalline to amorphous form. FT-IR showed coupling of zein NH group with ITZ carbonyl group without affecting ITZ antifungal activity as confirmed by antifungal activity test that showed enhanced activity of ITZ-ZNPs over the pure drug. Histopathological examination and cytotoxicity tests ensured biosafety and tolerance of ITZ-ZNPs to the colon tissue. The optimized formulation was then loaded into Eudragit S100-coated capsules and both in vitro release and in vivo X-ray imaging confirmed the success of such coated capsules in protecting ITZ from the release in stomach and intestine while targeting ITZ to the colon. The study proved that ITZ-ZNPs is promising and safe nanoparticulate system that can protect ITZ throughout the GIT and targeting its release to the colon with effectual focused local action for the treatment of colon fungal infections.

Preparation and in vitro evaluation of hot-melt extruded pectin-based pellets containing ketoprofen for colon targeting

This work developed high drug-load pellets for colon targeting in minimal steps by coupling hot-melt extrusion (HME) with a die-surface cutting pelletizer, offering a potential continuous pellet manufacturing process. Ketoprofen (KTP) was selected as a model drug for this study due to its thermal stability and severe upper gastrointestinal side effects. Low and high methoxyl grade pectins were the enzyme-triggered release matrix, and hydroxypropyl methylcellulose (HME 4 M/HME 100LV) was used as a premature release-retarding agent. The powder X-ray diffraction technique and the differential scanning calorimetry results revealed that KTP exists in the solid-solution state within the polymeric matrix after the HME step. The scanning electron micrographs of the fabricated pellets showed a smooth surface without any cracks. The lead formulation showed the lowest premature drug release (∼13%) with an extended KTP release profile over a 24 h period in the presence and absence of the release-triggering enzyme. The lead formulation was stable for 3 months at accelerated stability conditions (40 °C/75 ± 5% RH) concerning drug content, in vitro release, and thermal characteristics. In summary, coupling HME and pelletization processes could be a promising technology for developing colon-targeted drug delivery systems.

Development of Polymeric-Based Formulation as Potential Smart Colonic Drug Delivery System

Conventional oral formulations are mainly absorbed in the small intestine. This limits their use in the treatment of some diseases associated with the colon, where the drug has to act topically at the inflammation site. This paved the way for the development of a smart colonic drug delivery system, thereby improving the therapeutic efficacy, reducing the dosing frequency and potential side effects, as well as improving patient acceptance, especially in cases where enemas or other topical preparations may not be effective alone in treating the inflammation. In healthy individuals, it takes an oral medication delivery system about 5 to 6 h to reach the colon. A colonic drug delivery system should delay or prohibit the medication release during these five to six hours while permitting its release afterward. The main aim of this study was to develop a smart drug delivery system based on pH-sensitive polymeric formulations, synthesized by a free-radical bulk polymerization method, using different monomer and crosslinker concentrations. The formulations were loaded with 5-amino salicylic acid as a model drug and Capmul MCM C8 as a bioavailability enhancer. The glass transition temperature (Tg), tensile strength, Young’s modulus, and tensile elongation at break were all measured as a part of the dried films’ characterization. In vitro swelling and release studies were performed to assess the behavior of the produced formulations. The in vitro swelling and release evaluation demonstrated the potential ability of the developed system to retard the drug release at conditions mimicking the stomach and small intestine while triggering its release at conditions mimicking the colon, which indicates its promising applicability as a potential smart colonic drug delivery system.

Multiparticulate Systems of Meloxicam for Colonic Administration in Cancer or Autoimmune Diseases

The aim of this research is the development of new colonic release systems of meloxicam (MLX) a non-steroidal anti-inflammatory drug (NSAIDs) with pH and time-dependent vehicles for cancer or autoimmune diseases. The colon has a higher pH than the rest of the gastrointestinal tract (GIT) and this can be used as a modified release strategy. Eudragit^® polymers are the most widely used synthetic products in the design of colonic release formulations because they might offer mucoadhesiveness and pH-dependent release. Colonic delivery systems produced with pH-dependent and permeable polymers (FS-30D) or with pH-independent and low permeability polymers (NM-30D), must dissolve at a pH range of 6.0–7.0 to delay the release of the drug and prevent degradation in the GIT, before reaching the colon. The conditions prepared to simulate a gastrointestinal transit showed the CNM multiparticulate system, composed of Eudragit^® NM and cellulose, as the best release option for MLX with a more sustained release with respect to the other formulations. CNM formulation followed Higuchi and First-order release kinetics, thus MLX release was controlled by a combination of diffusion and polymers swelling/eroding processes.

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.

Advances in delivery methods of Arthrospira platensis (spirulina) for enhanced therapeutic outcomes

Arthrospira platensis (A. platensis) aqueous extract has massive amounts of natural products that can be used as future drugs, such as C-phycocyanin, allophycocyanin, etc. This extract was chosen because of its high adaptability, which reflects its resolute genetic composition. The proactive roles of cyanobacteria, particularly in the medical field, have been discussed in this review, including the history, previous food and drug administration (FDA) reports, health benefits and the various dose-dependent therapeutic functions that A. platensis possesses, including its role in fighting against lethal diseases such as cancer, SARS-CoV-2/COVID-19, etc. However, the remedy will not present its maximal effect without the proper delivery to the targeted place for deposition. The goal of this research is to maximize the bioavailability and delivery efficiency of A. platensis constituents through selected sites for effective therapeutic outcomes. The solutions reviewed are mainly on parenteral and tablet formulations. Moreover, suggested enteric polymers were discussed with minor composition variations applied for better storage in high humid countries alongside minor variations in the polymer design were suggested to enhance the premature release hindrance of basic drugs in low pH environments. In addition, it will open doors for research in delivering active pharmaceutical ingredients (APIs) in femtoscale with the use of various existing and new formulations.Abbrevations: SDGs; Sustainable Development Goals, IL-4; Interleukin-4, HDL; High-Density Lipoprotein, LDL; Low-Density Lipoprotein, VLDL; Very Low-Density Lipoprotein, C-PC; C-Phycocyanin, APC; Allophycocyanin, PE; Phycoerythrin, COX-2; Cyclooxygenase-2, RCTs; Randomized Control Trials, TNF-α; Tumour Necrosis Factor-alpha, γ-LFA; Gamma-Linolenic Fatty Acid, PGs; Polyglycans, PUFAs: Polyunsaturated Fatty Acids, NK-cell; Natural Killer Cell, FDA; Food and Drug Administration, GRAS; Generally Recognized as Safe, SD; Standard Deviation, API; Active Pharmaceutical Ingredient, DW; Dry Weight, IM; Intramuscular, IV; Intravenous, ID; Intradermal, SC; Subcutaneous, AERs; Adverse Event Reports, DSI-EC; Dietary Supplement Information Executive Committee, cGMP; Current Good Manufacturing Process, A. platensis; Arthrospira platensis, A. maxima; Arthrospira maxima, Spirulina sp.; Spirulina species, Arthrospira; Spirulina, Tecuitlatl; Spirulina, CRC; Colorectal Cancer, HDI; Human Development Index, Tf; Transferrin, TfR; Transferrin Receptor, FR; Flow Rate, CPP; Cell Penetrating Peptide, SUV; Small Unilamenar Vesicle, LUV; Large Unilamenar Vesicle, GUV; Giant Unilamenar Vesicle, MLV; Multilamenar Vesicle, COVID-19; Coronavirus-19, PEGylated; Stealth, PEG; Polyethylene Glycol, OSCEs; Objective Structured Clinical Examinations, GI; Gastrointestinal Tract, CAP; Cellulose Acetate Phthalate, HPMCP, Hydroxypropyl Methyl-Cellulose Phthalate, SR; Sustained Release, DR; Delay Release, Poly(MA-EA); Polymethyl Acrylic Co-Ethyl Acrylate, f-DR L-30 D-55; Femto-Delay Release Methyl Acrylic Acid Co-Ethyl Acrylate Polymer, MW; Molecular Weight, Tg; Glass Transition Temperature, SN2; Nucleophilic Substitution 2, EPR; Enhance Permeability and Retention, VEGF; Vascular Endothelial Growth Factor, RGD; Arginine-Glycine-Aspartic Acid, VCAM-1; Vascular Cell Adhesion Molecule-1, P; Coefficient of Permeability, PES; Polyether Sulfone, pHe; Extracellular pH, ζ-potential; Zeta potential, NTA; Nanoparticle Tracking Analysis, PB; Phosphate Buffer, DLS; Dynamic Light Scattering, AFM; Atomic Force Microscope, Log P; Partition Coefficient, MR; Molar Refractivity, tPSA; Topological Polar Surface Area, C log P; Calculated Partition Coefficient, CMR; Calculated Molar Refractivity, Log S; Solubility Coefficient, pka; Acid Dissociation Constant, DDAB; Dimethyl Dioctadecyl Ammonium Bromide, DOPE; Dioleoylphosphatidylethanolamine, GDP; Good Distribution Practice, RES; Reticuloendothelial System, PKU; Phenylketonuria, MS; Multiple Sclerosis, SLE; Systemic Lupus Erythematous, NASA; National Aeronautics and Space Administration, DOX; Doxorubicin, ADRs; Adverse Drug Reactions, SVM; Support Vector Machine, MDA; Malondialdehyde, TBARS; Thiobarbituric Acid Reactive Substances, CRP; C-Reactive Protein, CK; Creatine Kinase, LDH; Lactated Dehydrogenase, T2D; Type 2 Diabetes, PCB; Phycocyanobilin, PBP; Phycobiliproteins, PEB; Phycoerythrobilin, DPP-4; Dipeptidyl Peptidase-4, MTT; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, IL-2; Interleukin-2, IL-6; Interleukin-6, PRISMA; Preferred Reporting Items for Systematic Reviews and Meta-Analyses, STATA; Statistics, HepG2; Hepatoblastoma, HCT116; Colon Cancer Carcinoma, Kasumi-1; Acute Leukaemia, K562; Chronic Leukaemia, Se-PC; Selenium-Phycocyanin, MCF-7; Breast Cancer Adenocarcinoma, A375; Human Melanoma, RAS; Renin-Angiotensin System, IQP; Ile-Gln-Pro, VEP; Val-Glu-Pro, Mpro; Main Protease, PLpro; Papin-Like Protease, BMI; Body Mass Index, IC50; Inhibitory Concentration by 50%, LD50; Lethal Dose by 50%, PC12 Adh; Rat Pheochromocytoma Cells, RNS; Reactive Nitrogen Species, Hb1Ac; hemoglobin A1c.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Current Strategies and Potential Prospects of Nanomedicine-Mediated Therapy in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are highly debilitating. IBDs are associated with the imbalance of inflammatory mediators within the inflamed bowel. Conventional drugs for IBD treatment include anti-inflammatory medications and immune suppressants. However, they suffer from a lack of bioavailability and high dose-induced systemic side effects. Nanoparticle (NP)-derived therapy improves therapeutic efficacy and increases targeting specificity. Recent studies have shown that nanomedicines, based on bowel disease's pathophysiology, are a fast-growing field. NPs can prolong the circulation period and reduce side effects by improving drug encapsulation and targeted delivery. Here, this review summarizes various IBD therapies with a focus on NP-derived applications, whereas their challenges and future perspectives have also been discussed.

Nanoparticle-mediated gene therapy strategies for mitigating inflammatory bowel disease

Inflammatory bowel disease (IBD) is an autoimmune disorder of the gastrointestinal tract (GIT) where Ulcerative Colitis (UC) displays localized inflammation in the colon, and Crohn's Disease (CD) affects the entire GIT. Failure of current therapies and associated side-effects bring forth serious social, economic, and health challenges. The gut epithelium provides the best target for gene therapy delivery vehicles to combat IBD. Gene therapy involving the use of nucleic acid (NA) therapeutics faces major challenges due to the hydrophilic, negative-charge, and degradable nature of NAs. Recent success in the engineering of biomaterials for gene therapy and their emergence in clinical trials for various diseases is an inspiration for scientists to develop gene therapy vehicles that can be easily targeted to the desired tissues for IBD. Advances in nanotechnology have enabled the formulations of numerous nanoparticles for NA delivery to mitigate IBD that still faces challenges of stability in the GIT, poor therapeutic efficacy, and targetability. This review presents the challenges of gene therapeutics, gastrointestinal barriers, and recent advances in the engineering of nanoparticles for IBD treatment along with future directions for successful translation of nanoparticle-mediated gene therapeutics in clinics.

Therapeutic targeting of the oncogenic Wnt signaling pathway for treating colorectal cancer and other colonic disorders

The canonical Wnt pathway is one of the key cellular signaling cascades that regulates, via the transcriptional co-activator β-catenin, numerous embryogenic developmental processes, as well as tissue homeostasis. It is therefore not surprising that misregulation of the Wnt/β-catenin pathway has been implicated in carcinogenesis. Aberrant Wnt signaling has been reported in a variety of malignancies, and its role in both hereditary and sporadic colorectal cancer (CRC), has been the subject of intensive study. Interestingly, the vast majority of colorectal tumors harbor mutations in the tumor suppressor gene adenomatous polyposis coli (APC). The Wnt pathway is complex, and despite decades of research, the mechanisms that underlie its functions are not completely known. Thus, although the Wnt cascade is an attractive target for therapeutic intervention against CRC, one of the malignancies with the highest morbidity and mortality rates, achieving efficacy and safety is yet extremely challenging. Here, we review the current knowledge of the Wnt different epistatic signaling components and the mechanism/s by which the signal is transduced in both health and disease, focusing on CRC. We address some of the important questions in the field and describe various therapeutic strategies designed to combat unregulated Wnt signaling, the development of targeted therapy approaches and the emerging challenges that are associated with these advanced methods.

Bupleuri Radix Prevents the Recurrences of Resected Colonic Polyps by Affecting Angiogenin-2-Induced Protein Kinase B/Akt Signaling

Aim

We aimed to explore the effects of Bupleuri Radix (BR) on the recurrence of resected colonic polyp (CP) by measuring angiogenin-2-induced protein kinase B (Ang PKB)/Akt signaling.

Method

The main ingredients of BR were extracted by using ethanol and measured by HPLC. One hundred twenty patients with CP >10 mm who underwent resected surgery were randomly allocated to an aspirin (AG) or a BR medicine (BG) group. The allocation ratio was 1 : 1 and the intervention duration was one year. The recurrence rate of resected CP was investigated and the plasma levels of Ang PKB/Akt and inflammatory cytokines were measured using ELISA kits. After one-year surgery, side effects were recorded. The relationship between the serum levels of the main compounds of BR and plasma levels of Ang PKB/Akt was analyzed.

Results

The main ingredients of CP are paeoniflorin, baicalin, saikosaponin A, and bupleurum saponin B2. Recurrence of resected CP was found in 17 patients from the AG group and eight patients from the BG group after one-year follow-up (p < 0.05). The levels of angiogenin-2 II and PKB/Akt in the AG group were higher than those in the BG group (p < 0.05). Meanwhile, BR treatment reduced the plasma levels of TNF-α, IL-1β, and IL-6, and increased the level of IL-10(p < 0.05). Inflammatory cytokines are important factors that affect the recurrence of resected CP. Serum paeoniflorin, baicalin, saikosaponin A, and bupleurum saponin B2 in BR had a strong negative relationship with the plasma levels of Ang PKB/Akt.

Conclusion

BR significantly reduces the recurrence risk of resected CP by affecting Ang PKB/Akt signaling.

Natural proteins and polysaccharides in the development of micro/nano delivery systems for the treatment of inflammatory bowel disease

Treatments for inflammatory bowel disease (IBD) are typically immunosuppressive. Despite a range of treatment options, limited efficacy, systemic toxicities like bone marrow suppression, infections and malignancy are their serious setbacks. There exists an unmet medical need for novel therapeutic agents without safety concerns resulting from chronic, systemic immunosuppression. Of late, several natural agents with better therapeutic potential have been reported. It is very likely that restricting the release of the active molecules to the intestine would further improve their clinical efficacy and safety. To this end, novel polymer-based micro/nano formulations protect the drug from gastric environment and slowly release the drug in the colon. However, cost and side-effects associated to synthetic polymers have led to the development of biocompatible, economic and pharmaceutically well-accepted biomacromolecules in exploring their potential in IBD. Since last few years, biological proteins, polysaccharides and their combinations have shown great efficacy in colitis induced animal models. In this review, micro/nano formulations developed using biomacromolecules like chitosan, zein, pectin, casein, alginate, dextran, glucomannan and hyaluronic acid have been reviewed focusing on their potential in protecting active cargo, avoiding premature release, distal colon targeting along with their impact on reshaping the altered gut microbiota and how it can ameliorate the colitis conditions.

Engineered Site-specific Vesicular Systems for Colonic Delivery: Trends and Implications

Steering drug-loaded, site-specific, coated lipid vesicles to the target receptor sites have the potential of plummeting adverse effects and improving the pharmacological response in diverse pathologies of the large bowel, especially the colon. Colonic delivery via oral route has its own challenges, often governed by several glitches such as drug degradation or absorption in the upper GIT, instability of proteins/peptides due to high molecular weight, and peptidase activity in the stomach. Consequently, colon-specific coated liposomal systems (CSLS) offer a potential alternate for not only site-specificity, but protection from proteolytic activity, and prolonged residence time for greater systemic bioavailability. On the other hand, liposomal delivery via the oral route is also cumbersome owing to several barriers such as instability in GIT, difficulty in crossing membranes, and issues related to production at the pilot scale. New advancements in the field of CSLS have successfully improved the stability and permeability of liposomes for oral delivery via modulating the compositions of lipid bilayers, adding polymers or ligands. Despite this ostensible propitiousness, no commercial oral CSLS has advanced from bench to bedside for targeted delivery to the colon as yet. Nevertheless, CSLS has quite fascinated the manufacturers owing to its potential industrial viability, simplistic and low-cost design. Hence, this review aims to decipher the convolutions involved in the engineering process of industrially viable CSLS for colonic delivery.

Colon targeted bioadhesive pellets of curcumin and cyclosporine for improved management of inflammatory bowel disease

The objective of the present work was to develop and optimize multiparticulate pH-dependent bioadhesive pellets of curcumin and cyclosporine for the management of intestinal bowel disease (IBD). The bioadhesive sustained release pellets were intended for targeting the affected site for an improved therapeutic effect. Bioadhesive pellet cores of curcumin and cyclosporine were formulated using Carbopol 940 (CP940) and hydroxypropyl cellulose (HPC-H) by the extrusion/spheronization method, and drug delivery to the colon was controlled by the pH-sensitive polymer Eudragit® S100. Microcrystalline cellulose (Avicel PH101) was found to be the best forming agent for pellet core. The ratio of CP940 to HPC-H was kept at 1:1 to achieve 100% bioadhesion. The in vitro dissolution profiles of coated pellets depicted that 12.327 ± 0.342% of curcumin and 14.751 ± 0.112% of cyclosporine were released at the end of 6 h (at pH 6.8), whereas 71.278 ± 0.100% of curcumin and 76.76 ± 0.195% of cyclosporine were released at the end of 24 h (at pH 7.4). The drug release profile was found to follow zero-order kinetics for both drugs. The selected formulation was evaluated on an acetic acid-induced ulcerative colitis in the rat model to evaluate the efficiency of drug-loaded pellets coated with Eudragit®S100. The pharmacodynamic study revealed the therapeutic efficacy of Eudragit®S100-coated pellets of curcumin and cyclosporine in alleviating the conditions of the acetic acid-induced colitis model as reflected by weight gain as well as improvement of clinical, macroscopic and microscopic parameters of induced colitis, as compared with free curcumin and cyclosporine. The combination of curcumin and cyclosporine has been proven to have a synergistic effect for the successful management of IBD when used in a low dose as compared with individual drugs with high doses. Hence, curcumin- and cyclosporine-loaded bioadhesive pellets may act as a promising targeted drug delivery system in the management of IBD. Graphical abstract.

Targeting the pregnane X receptor using microbial metabolite mimicry

The human PXR (pregnane X receptor), a master regulator of drug metabolism, has essential roles in intestinal homeostasis and abrogating inflammation. Existing PXR ligands have substantial off-target toxicity. Based on prior work that established microbial (indole) metabolites as PXR ligands, we proposed microbial metabolite mimicry as a novel strategy for drug discovery that allows exploiting previously unexplored parts of chemical space. Here, we report functionalized indole derivatives as first-in-class non-cytotoxic PXR agonists as a proof of concept for microbial metabolite mimicry. The lead compound, FKK6 (Felix Kopp Kortagere 6), binds directly to PXR protein in solution, induces PXR-specific target gene expression in cells, human organoids, and mice. FKK6 significantly represses pro-inflammatory cytokine production cells and abrogates inflammation in mice expressing the human PXR gene. The development of FKK6 demonstrates for the first time that microbial metabolite mimicry is a viable strategy for drug discovery and opens the door to underexploited regions of chemical space.

Coumarins into Polyurethanes for Smart and Functional Materials

Polyurethanes are of undoubted interest for the scientific community and the industry. Their outstanding versatility from tailor-made structures turns them into major polymers for use in a wide range of different applications. As with other polymers, new, emerging molecules and monomers with specific attributes can provide new functions and capabilities to polyurethanes. Natural and synthetic coumarin and its derivatives are characterised by interesting biological, photophysical and photochemical properties. Then, the polyurethanes can exploit those features of many coumarins which are present in their composition to achieve new functions and performances. This article reviews the developments in the proper use of the special properties of coumarins in polyurethanes to produce functional and smart materials that can be suitable for new specific applications.

Factors Influencing Drug Disposition of Monoclonal Antibodies in Inflammatory Bowel Disease: Implications for Personalized Medicine

Monoclonal antibody (mAb) therapies have revolutionized the treatment of several chronic inflammatory diseases, including the inflammatory bowel diseases (IBD), Crohn's disease, and ulcerative colitis. While efficacious, responses to these therapies vary considerably from patient to patient, due in part to inter- and intra-individual variability in pharmacokinetics (PK) and drug exposure. The concept of personalized medicine to monitor drug exposure and to adjust dosing in individual patients is consequently gaining acceptance as a powerful tool to optimize mAb therapy for improved outcomes in IBD. This review provides a brief overview of the different mAbs currently approved or in development for the treatment of IBD, including their presumed mechanisms of action and PK properties. Specifically described are (1) the factors known to affect mAb PK and drug exposure in patients with IBD, (2) the value of population PK/pharmacodynamic (PD) modeling to identify and understand the influence of these factors on drug exposure and effect, and (3) the clinical evidence for the potential of therapeutic drug monitoring (TDM) to improve IBD outcomes in response to mAb-based therapy. Incorporation of PK/PD parameters into clinical decision support tools has the potential to guide therapeutic decision making and aid implementation of personalized medicine strategies in patients with IBD.

Stimuli-Responsive Polymeric Nanosystem for Colon Specific Drug Delivery

An ideal colon specific drug delivery system needs to perform multiple functions like greater bio availability, less toxicity and higher therapeutic efficacy, all of which require high degree of smartness. This article focuses on the overview of the stimuli-responsive polymers and various nanodrug delivery systems which have found applications in colon specific delivery of drugs as this system provide a link between therapeutic need and drug delivery. These polymers exhibit a non-linear response to a small stimulus leading to a macroscopic alteration in their structure/properties. Stimuli responsive polymers display a significant physio chemical change in response to small changes in their environment (temperature, pH, light etc.). Colonic drug delivery has gained increased importance in treating diseases like Crohn's disease, ulcerative colitis, colon cancer etc. The expansion in the development of polymers based system with greater flexibility, versatility and unexplored potential enables new opportunities for them in uplifting bio medicine. Applying the concepts of smartness in the context of clinically relevant therapeutic and diagnostic systems, it can prelude in a new era of 'smart' therapeutics that can improve the health care fields. In particular, due to its high sensitivity to the stimuli, this system has been identified as a sensible platform for releasing drug at suitable site and at appropriate time.

Pectin and Zinc Alginate: The Right Inner/Outer Polymer Combination for Core-Shell Drug Delivery Systems

Core-shell beads loaded with betamethasone were developed using co-axial prilling as production technique and pectin plus alginate as polymeric carriers. During this study, many operative conditions were intensively investigated to find the best ones necessary to produce uniform core-shell particle systems in a reproducible way. Particularly, feed solutions' composition, polymers mass ratios and the effect of the main process parameters on particles production, micromeritics, inner structure, drug loading and drug-release/swelling profiles in simulated biological fluids were studied. The optimized core-shell formulation F5 produced with a pectin core concentration of 4.0% w/v and an alginate shell concentration of 2.0% w/v (2:1 core:shell ratio) acted as a sustained drug delivery system. It was able to reduce the early release of the drug in the upper part of the gastro-intestinal tract for the presence of the zinc-alginate gastro-resistant outer layer and to specifically deliver it in the colon, thanks to the selectivity of amidated low methoxy pectin core for this district. Therefore, these particles may be proposed as colon targeted drug delivery systems useful for inflammatory bowel disease (IBD) therapy.

Strategic Approaches for Colon Targeted Drug Delivery: An Overview of Recent Advancements

Colon targeted drug delivery systems have gained a great deal of attention as potential carriers for the local treatment of colonic diseases with reduced systemic side effects and also for the enhanced oral delivery of various therapeutics vulnerable to acidic and enzymatic degradation in the upper gastrointestinal tract. In recent years, the global pharmaceutical market for biologics has grown, and increasing demand for a more patient-friendly drug administration system highlights the importance of colonic drug delivery as a noninvasive delivery approach for macromolecules. Colon-targeted drug delivery systems for macromolecules can provide therapeutic benefits including better patient compliance (because they are pain-free and can be self-administered) and lower costs. Therefore, to achieve more efficient colonic drug delivery for local or systemic drug effects, various strategies have been explored including pH-dependent systems, enzyme-triggered systems, receptor-mediated systems, and magnetically-driven systems. In this review, recent advancements in various approaches for designing colon targeted drug delivery systems and their pharmaceutical applications are covered with a particular emphasis on formulation technologies.