Bioadhesive pellets increase local 5-aminosalicylic acid concentration in experimental colitis

Optimization, cellular uptake, and in vivo evaluation of Eudragit S100-coated bile salt-containing liposomes for oral colonic delivery of 5-aminosalicylic acid

Eudragit S100-coated bile salt-containing liposomes were prepared and optimized by experimenting with different variables, including bile salt type and concentration, and the method of incorporation into liposomes using a model hydrophilic compound, 5-aminosalicylic acid (5-ASA). After optimizing the formulation, cellular uptake, and animal pharmacokinetic experiments were performed. The inclusion of sodium glycocholate (SG) into liposomes decreased liposome particle size and entrapment efficiency significantly but had no effect on zeta potential. The method of incorporating SG into the lipid or aqueous phase of the liposome did not notably impact the characteristics of the liposomes but the hydration media had a substantial effect on the entrapment efficiency of 5-ASA. In vitro drug release in different fluids simulating distinct gastrointestinal tract sections, indicated pH-dependent disintegration of the coating layer of coated SG-containing liposomes. The majority of the drug was retained when subjected to simulated gastric fluid (SGF) and fed-state simulated intestinal fluid (FeSSIF) (≈ 37% release after 2 h in SGF pH 1.2, followed by 3 h in FeSSIF pH 5). The remaining drug was subsequently released in phosphate-buffered saline pH 7.4 (≈ 85% release within 24 h). Increasing SG concentration in the liposomes decreased the amount of drug released in FeSSIF. Similar results were observed when SG was replaced with sodium taurocholate. Cellular uptake studies in Caco-2 cells demonstrated that all liposomal formulations (conventional liposomes, bile salt-containing liposomes, and coated bile salt-containing liposomes) have shown to be equally effective at increasing the cellular uptake compared to free fluorescein solution. In the pharmacokinetic study, coated bile salt-containing liposomes showed a lower Cmax and prolonged residence in the gastrointestinal tract in comparison to conventional liposomes. Taken together, these findings suggest that the polymer-coated bile salt-containing liposomes have the potential to serve as a drug delivery system targeted at the colon.

Microbiota-sensitive drug delivery systems based on natural polysaccharides for colon targeting

Colon targeting is an ongoing challenge, particularly for the oral administration of biological drugs or local treatment of inflammatory bowel disease (IBD). In both cases, drugs are known to be sensitive to the harsh conditions of the upper gastrointestinal tract (GIT) and, thus, must be protected. Here, we provide an overview of recently developed colonic site-specific drug delivery systems based on microbiota sensitivity of natural polysaccharides. Polysaccharides act as a substrate for enzymes secreted by the microbiota located in the distal part of GIT. The dosage form is adapted to the pathophysiology of the patient and, thus, a combination of bacteria-sensitive and time-controlled release or pH-dependent systems can be used for delivery.

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.

Bioadhesive Tannic-Acid-Functionalized Zein Coating Achieves Engineered Colonic Delivery of IBD Therapeutics via Reservoir Microdevices

The biggest challenge in oral delivery of anti-inflammatory drugs such as 5-aminosalicylic acid (5-ASA) is to (i) prevent rapid absorption in the small intestine and (ii) achieve localized release at the site of inflammation in the lower gut, i.e., the colon. Here, we present an advanced biopolymeric coating comprising of tannic-acid-functionalized zein protein to provide a sustained, colon-targeted release profile for 5-ASA and enhance the mucoadhesion of the dosage form via a mussel-inspired mechanism. To enable localized delivery and provide high local concentration, 5-ASA is loaded into the microfabricated drug carriers (microcontainers) and sealed with the developed coating. The functionality and drug release profile of the coating are characterized and optimized in vitro, showing great tunability, scalability, and stability toward proteases. Further, ex vivo experiments demonstrate that the tannic acid functionalization can significantly enhance the mucoadhesion of the coating, which is followed up by in vivo investigations on the intestinal retention, and pharmacokinetic evaluation of the 5-ASA delivery system. Results indicate that the developed coating can provide prolonged colonic delivery of 5-ASA. Therefore, the here-developed biodegradable coating can be an eco-friendly substitute to the state-of-the-art commercial counterparts for targeted delivery of 5-ASA and other small molecule drugs.

Designing of pH-Sensitive Hydrogels for Colon Targeted Drug Delivery; Characterization and In Vitro Evaluation

In the current research work, pH-sensitive hydrogels were prepared via a free radical polymerization technique for the targeted delivery of 5-aminosalicylic acid to the colon. Various proportions of chitosan, β-Cyclodextrin, and acrylic acid were cross-linked by ethylene glycol dimethacrylate. Ammonium persulfate was employed as an initiator. The development of a new polymeric network and the successful encapsulation of the drug were confirmed by Fourier transform infrared spectroscopy. Thermogravimetric analysis indicated high thermal stability of the hydrogel compared to pure chitosan and β-Cyclodextrin. A rough and hard surface was revealed by scanning electron microscopy. Similarly, the crystallinity of the chitosan, β-Cyclodextrin, and fabricated hydrogel was evaluated using powder X-ray diffraction. The swelling and drug release studies were performed in both acidic and basic medium (pH 1.2 and 7.4, respectively) at 37 °C. High swelling and drug release was observed at pH 7.4 as compared to pH 1.2. The increased incorporation of chitosan, β-Cyclodextrin, and acrylic acid led to an increase in porosity, swelling, loading, drug release, and gel fraction of the hydrogel, whereas a decrease in sol fraction was observed. Thus, we can conclude from the results that a developed pH-sensitive network of hydrogel could be employed as a promising carrier for targeted drug delivery systems.

Clinical translation of advanced colonic drug delivery technologies

Targeted drug delivery to the colon offers a myriad of benefits, including treatment of local diseases, direct access to unique therapeutic targets and the potential for increasing systemic drug bioavailability and efficacy. Although a range of traditional colonic delivery technologies are available, these systems exhibit inconsistent drug release due to physiological variability between and within individuals, which may be further exacerbated by underlying disease states. In recent years, significant translational and commercial advances have been made with the introduction of new technologies that incorporate independent multi-stimuli release mechanisms (pH and/or microbiota-dependent release). Harnessing these advanced technologies offers new possibilities for drug delivery via the colon, including the delivery of biopharmaceuticals, vaccines, nutrients, and microbiome therapeutics for the treatment of both local and systemic diseases. This review details the latest advances in colonic drug delivery, with an emphasis on emerging therapeutic opportunities and clinical technology translation.

How could nanobiotechnology improve treatment outcomes of anti-TNF-α therapy in inflammatory bowel disease? Current knowledge, future directions

Despite significant advances in therapeutic possibilities for the treatment of inflammatory bowel disease (IBD) in recent years, there is still a big room for improvement. In particular, biological treatment can induce not only clinical remission but also mucosal healing of the gastrointestinal tract. Among these therapeutic molecules, anti-tumor necrosis factor-alpha (anti-TNF-α) antibodies were the first to revolutionize treatment algorithms in IBD. However, due to the parenteral route of administration and systemic mode of action, TNF-α blockers are characterised by high rates of immunogenicity-related loss of response and serious adverse events. Moreover, intravenous or subcutaneous therapy is not considered patient-friendly and requires occasional, direct contact with healthcare centres. To overcome these limitations, several attempts have been made to design oral pharmaceutical formulations of these molecules. It is hypothesized that oral anti-TNF-α antibodies therapy can directly provide a targeted and potent anti-inflammatory effect in the inflamed gastrointestinal tissues without significant systemic exposure, improving long-term treatment outcomes and safety. In this review, we discuss the current knowledge and future perspectives regarding different approaches made towards entering a new era of oral anti-TNF-α therapy, namely, the tailoring of biocompatible nanoparticles with anti-TNF-α antibodies for site-specific targeting to IBD. In particular, we discuss the latest concepts applying the achievements of nanotechnology-based drug design in this area.

Anti-inflammatory effects of acacia and guar gum in 5-amino salicylic acid formulations in experimental colitis

Findings from recent studies revealed a significant anti-inflammatory effect of polysaccharide-based excipients when formulated with classical drugs in experimental inflammatory bowel disease models. In this study, acacia and guar gum were investigated beyond their typical functionality for a possible additive anti-inflammatory effect when administered with 5-amino salicylic acid (5ASA) in murine experimental colitis. Anti-inflammatory effects of acacia and guar gum-based aqueous suspensions of 5ASA were evaluated in a murine experimental colitis. Acacia or guar gum (30 or 300 mg/kg) were administered via rectal administration alone or in combination with 5ASA (30 mg/kg). Disease activity, myeloperoxidase activity (MPO) and intratissue concentrations of various cytokines were assessed. Both acacia and guar gum separately showed significant effects in reducing the inflammatory markers in murine colitis model in vivo. When combined with the anti-inflammatory drug 5ASA, acacia showed a stronger therapeutic effect than guar gum, especially at the higher dose of acacia (300 mg/kg) which significantly reduced the inflammation in vivo compared to 5ASA alone (MPO, 5ASA: 5743 ± 1334, 5ASA + 30 mg/kg acacia: 3762 ± 2342; 5ASA + 30 mg/kg guar gum: 7373 ± 2115, 5ASA + 300 mg/kg acacia: 3131 ± 1012, 5ASA + 300 mg/kg guar gum: 6358 ± 2379; all U/g tissue). Acacia and guar gum separately showed significant anti-inflammatory effects in murine colitis, and furthermore, high dose acacia led to an additional therapeutic benefit when co-administered with 5ASA. These results indicate that further investigations are surely warranted in the search of better colitis therapy.

Boston Ivy-Inspired Disc-Like Adhesive Microparticles for Drug Delivery

Microparticles with strong adherence are expected as efficient drug delivery vehicles. Herein, we presented an ingenious hydrogel microparticle recapitulating the adhesion mechanism of Boston ivy tendrils adhesive discs (AD) for durable drug delivery. The particles were achieved by replicating a silica colloidal crystal aggregates assembled in a droplet template after rapid solvent extraction. Due to their unique shape, the nanostructure, and the sticky hydrogel component, such novel microparticles exhibited prominent adhesive property to the wet tissue environment. It was demonstrated that the bioinspired microcarriers loading with dexamethasone had a good therapeutic effect for ulcerative colitis due to the strong adhesion ability for prolonging the maintenance of drug availability. These virtues make the biomimetic microparticles potentially ideal for many practical clinical applications, such as drug delivery, bioimaging, and biodiagnostics.

The Effect of Thermal-Treating on Drug Release from Sustained Release Alginate-Eudragit RS Matrices

Purpose: The main objective of the present study was to develop the colonic delivery system for 5-aminosalicylic acid (5-ASA) as an anti-inflammatory drug.

Methods: Matrix pellets containing various proportions of alginate, calcium and Eudragit^® RS were prepared by extrusion-spheronization technique. Thermal treatment was used to investigate the effect of the curing process on the surface morphology, mechanical and physicochemical properties and in vitro drug release profile of pellets. Based on the obtained results optimal formulations were selected to coating by the Eudragit^® RS and subjected to a subsequent continuous dissolution test.

Results: Image analysis and also scanning electron microscopy results proved acceptable morphology of the pellets. The fourier transform infrared spectroscopy and differential scanning calorimetry studies ruled out any interactions between the formulation’s components. Curing process did not alter the mechanical properties of pellets. The release rate of the drug from matrices was prolonged due to the decreased porosity of cured pellets. Furthermore, selected cured pellets which coated with Eudragit^® RS, prevented undesired premature drug release.

Conclusion: Formulation containing 17.5% calcium, 17.5% alginate, and a coating level of 10% demonstrated enhanced drug release so that provided resistance to acidic conditions, allowing complete drug release in alkaline pH, mimicking colonic environment. The slow and consistent drug release from this formulation could be used for treatment of a broader range of Inflammatory bowel disease (IBD) patients especially in whom colonic pH levels have been measured at lower than pH 7.0.

Exploitation of Marine-Derived Robust Biological Molecules to Manage Inflammatory Bowel Disease

Naturally occurring biological entities with extractable and tunable structural and functional characteristics, along with therapeutic attributes, are of supreme interest for strengthening the twenty-first-century biomedical settings. Irrespective of ongoing technological and clinical advancement, traditional medicinal practices to address and manage inflammatory bowel disease (IBD) are inefficient and the effect of the administered therapeutic cues is limited. The reasonable immune response or invasion should also be circumvented for successful clinical translation of engineered cues as highly efficient and robust bioactive entities. In this context, research is underway worldwide, and researchers have redirected or regained their interests in valorizing the naturally occurring biological entities/resources, for example, algal biome so-called "treasure of untouched or underexploited sources". Algal biome from the marine environment is an immense source of excellence that has also been demonstrated as a source of bioactive compounds with unique chemical, structural, and functional features. Moreover, the molecular modeling and synthesis of new drugs based on marine-derived therapeutic and biological cues can show greater efficacy and specificity for the therapeutics. Herein, an effort has been made to cover the existing literature gap on the exploitation of naturally occurring biological entities/resources to address and efficiently manage IBD. Following a brief background study, a focus was given to design characteristics, performance evaluation of engineered cues, and point-of-care IBD therapeutics of diverse bioactive compounds from the algal biome. Noteworthy potentialities of marine-derived biologically active compounds have also been spotlighted to underlying the impact role of bio-active elements with the related pathways. The current review is also focused on the applied standpoint and clinical translation of marine-derived bioactive compounds. Furthermore, a detailed overview of clinical applications and future perspectives are also given in this review.

Application of inulin/Eudragit RS in 5-ASA pellet coating with tuned, sustained-release feature in an animal model of ulcerative colitis

A tunable release of 5-aminosalicylic acid (5-ASA) could bring therapeutic benefits in the treatment of inflammatory bowel disease (IBD). A 3² factorial design was used to achieve a tuned delivery of 5-ASA pellets in the small and large intestine using a coating composed of inulin/Eudragit RS (RS). The ratio of inulin/RS and coating level were independent variables while the dependent variables were the percent of drug release at pH 1.2 in 2 h and total release of drug in 10 h at pH 6.8. 5-ASA release from pellets was examined at different pH levels and the therapeutic efficacy of the optimum pellets was compared to 5-ASA pellets of Pentasa in rats with ulcerative colitis. The inulin/RS of 18/82 at a coating level of 16% was found to be the optimum for delivery of the drug to the small and large intestine. The coated pellets offered a superior therapeutic outcome compared to uncoated pellets and Pentasa in terms of colitis activity index (CAI), and the colon's tissue enzymes of GSH and MDA. The optimum coating composed of inulin and RS could offer a tuned sustained release of 5-ASA throughout the small and large intestine with the sensitivity of drug release to microbial degradation.

Application of Polymeric Nano-Materials in Management of Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) is an umbrella term used to describe disorders that involve Crohn's disease (CD), ulcerative colitis (UC) and pouchitis. The disease occurrence is more prevalent in the working group population which not only hampers the well being of an individual but also has negative economical impact on society. The current drug regime used therapy is very costly owing to the chronic nature of the disease leading to several side effects. The condition gets more aggravated due to the lower concentration of drug at the desired site. Therefore, in the present scenario, a therapy is needed which can maximize efficacy, adhere to quality of life, minimize toxicity and doses, be helpful in maintaining and stimulating physical growth of mucosa with minimum disease complications. In this aspect, nanotechnology intervention is one promising field as it can act as a carrier to reduce toxicity, doses and frequency which in turn help in faster recovery. Moreover, nanomedicine and nanodiagnostic techniques will further open a new window for treatment in understanding pathogenesis along with better diagnosis which is poorly understood till now. Therefore the present review is more focused on recent advancements in IBD in the application of nanotechnology.

Anti-Inflammatory Activity of Chitosan and 5-Amino Salicylic Acid Combinations in Experimental Colitis

Chitosan is used in various drug delivery approaches as a pharmaceutical excipient. Although its potential as an immunomodulatory agent has been reported, its use in this capacity has not been fully explored. The efficacy of chitosan as an active pharmacological agent, particularly in anti-inflammatory therapy in inflammatory bowel diseases (IBD), was investigated in this study. The potential impact of the molecular weight (MW) and degree of deacetylation (DD) of chitosan was investigated together with 5-amino salicylic acid (5-ASA) for its efficacy in a combination anti-inflammatory therapy in murine experimental colitis. Such a combination would potentially be developed into novel dual strategies whereby chitosan acts as a mucoadhesive excipient as well as provide an additional anti-inflammatory benefit. Chitosan grades with different MW and DD were administered intrarectally alone or in combination with 5-ASA to colitis mice for 3 days. Myeloperoxidase (MPO) and alkaline phosphatase (ALP) activity and tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and nuclear factor kappa-B (NF-κB) levels were assessed from the colon. Intrarectal treatment of colitis with 30 mg/kg chitosan alone and with 30 mg/kg 5-ASA for 3 days led to a significant decrease in MPO, ALP, TNF-α, IL-6, IL-1β and NF-κB in colitis mice compared to untreated mice. Surprisingly, the efficacy of chitosan as an anti-inflammatory polymer was relatively independent from its structural properties, namely DD and MW. However, combinations of chitosan with 5-ASA showed a significant pharmacological improvement, whereby the additive anti-inflammatory efficacy observed shows the possibility of finetuning chitosan by combining it with anti-inflammatory agents to optimize its anti-inflammatory potential.

Nanocomposites-based targeted oral drug delivery systems with infliximab in a murine colitis model

Background

Infliximab (IFX), a TNF-α blocking chimeric monoclonal antibody, induces clinical response and mucosal healing in patients with inflammatory bowel disease (IBD). However, systemic administration of this agent causes unwanted side effects. Oral delivery of antibody therapeutics might be an effective treatment strategy for IBD compared to intravenous administration.

Results

All three carriers had a high encapsulation efficiency, narrow size distribution, and minimal systemic exposure. There was a higher interaction between nanocomposite carriers and monocytes compared to lymphocytes in the PBMC of IBD patients. Orally administered nanocomposite carriers targeted to inflamed colitis minimized systemic exposure. All IFX delivery formulations with nanocomposite carriers had a significantly less colitis-induced body weight loss, colon shortening and histomorphological score, compared to the DSS-treated group. AC-IFX-L and EAC-IFX-L groups showed significantly higher improvement of the disease activity index, compared to the DSS-treated group. In addition, AC-IFX-L and EAC-IFX-L alleviated pro-inflammatory cytokine expressions (Tnfa, Il1b, and Il17).

Conclusion

We present orally administered antibody delivery systems which improved efficacy in murine colitis while reducing systemic exposure. These oral delivery systems suggest a promising therapeutic approach for treating IBD.

Expedition of Eudragit® Polymers in the Development of Novel Drug Delivery Systems

Eudragit® polymer has been widely used in film-coating for enhancing the quality of products over other materials (e.g., shellac or sugar). Eudragit® polymers are obtained synthetically from the esters of acrylic and methacrylic acid. For the last few years, they have shown immense potential in the formulations of conventional, pH-triggered, and novel drug delivery systems for incorporating a vast range of therapeutics including proteins, vitamins, hormones, vaccines, and genes. Different grades of Eudragit® have been used for designing and delivery of therapeutics at a specific site via the oral route, for instance, in stomach-specific delivery, intestinal delivery, colon-specific delivery, mucosal delivery. Further, these polymers have also shown their great aptitude in topical and ophthalmic delivery. Moreover, available literature evidences the promises of distinct Eudragit® polymers for efficient targeting of incorporated drugs to the site of interest. This review summarizes some potential researches that are being conducted by eminent scientists utilizing the distinct grades of Eudragit® polymers for efficient delivery of therapeutics at various sites of interest.

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.

A review on 5-aminosalicylic acid colon-targeted oral drug delivery systems

Site-specific colon drug delivery is a practical approach for the treatment of local diseases of the colon with several advantages such as rapid onset of action and reduction of the dosage of the drug as well as minimization of harmful side effects. 5-aminosalicylic acid (5-ASA) is a drug of choice in the treatment of inflammatory bowel disease and colitis. For the efficient delivery of this drug, it is vital to prevent 5-ASA release in the upper part of the gastrointestinal tract and to promote its release in the proximal colon. Different approaches including chemical manipulation of drug molecule for production of prodrugs or modification of drug delivery systems using pH-dependent, time-dependent and/or bacterially biodegradable materials have been tried to optimize 5-ASA delivery to the colon. In the current review, the different strategies utilized in the design and development of an oral colonic delivery dosage form of 5-ASA are presented and discussed.

Preparation and in vitro-in vivo evaluation of intestinal retention pellets of Berberine chloride to enhance hypoglycemic and lipid-lowing efficacy

Berberine chloride (BBR) is a pharmacokinetic profile of drug with poor bioavailability but good therapeutic efficacy, which is closely related to the discovery of BBR intestinal target. The major aim of this paper is to develop BBR intestinal retention type sustained-release pellets and evaluate their in vivo and in vitro behaviors base on the aspect of local action on intestinal tract. Here, wet milling technology is used to improve dissolution and dissolution rate of BBR by decreasing the particle size and increasing the wettability. The pellets are prepared by liquid layer deposition technology, and then the core pellets are coated with Eudragit^® L30D-55 and Eudragit^® NE30D aqueous dispersion. The prepared pellets show high drug loading capacity, and the drug loading up to 93%. Meanwhile, it possesses significant sustained drug release effect in purified water which is expected to improve the pharmacokinetic behavior of BBR. The pharmacokinetics results demonstrate that the half-life of BBR was increased significantly from 24 h to 36 h and the inter- and intra-subject variability are decreased compared to commercial BBR tablets. The retention test results indicate that the pellet size and Eudragit^® NE30D plays an important role in retention time of the pellet, and it is found that the pellets with small particle size and high Eudragit^® NE30D coating content can stay longer in the intestine than the pellets with large particle size. All in all, BBR intestinal retention type pellets are prepared successfully in this study, and the pellets show satisfactory in vivo and in vitro behaviors.

The in vivo fate of nanoparticles and nanoparticle-loaded microcapsules after oral administration in mice: Evaluation of their potential for colon-specific delivery

Anti-cancer drug loaded-nanoparticles (NPs) or encapsulation of NPs in colon-targeted delivery systems shows potential for increasing the local drug concentration in the colon leading to improved treatment of colorectal cancer. To investigate the potential of the NP-based strategies for colon-specific delivery, two formulations, free Eudragit® NPs and enteric-coated NP-loaded chitosan-hypromellose microcapsules (MCs) were fluorescently-labelled and their tissue distribution in mice after oral administration was monitored by multispectral small animal imaging. The free NPs showed a shorter transit time throughout the mouse digestive tract than the MCs, with extensive excretion of NPs in faeces at 5h. Conversely, the MCs showed complete NP release in the lower region of the mouse small intestine at 8h post-administration. Overall, the encapsulation of NPs in MCs resulted in a higher colonic NP intensity from 8h to 24h post-administration compared to the free NPs, due to a NP 'guarding' effect of MCs during their transit along mouse gastrointestinal tract which decreased NP excretion in faeces. These imaging data revealed that this widely-utilised colon-targeting MC formulation lacked site-precision for releasing its NP load in the colon, but the increased residence time of the NPs in the lower gastrointestinal tract suggests that it is still useful for localised release of chemotherapeutics, compared to NP administration alone. In addition, both formulations resided in the stomach of mice at considerable concentrations over 24h. Thus, adhesion of NP- or MC-based oral delivery systems to gastric mucosa may be problematic for colon-specific delivery of the cargo to the colon and should be carefully investigated for a full evaluation of particulate delivery systems.

Mucoadhesive formulation of Bidens pilosa L. (Asteraceae) reduces intestinal injury from 5-fluorouracil-induced mucositis in mice

Gastrointestinal mucositis induced during cancer treatment is considered a serious dose-limiting side effect of chemotherapy and/or radiotherapy. Frequently, interruption of the cancer treatment due to this pathology leads to a reduction in cure rates, increase of treatment costs and decrease life quality of the patient. Natural products such as Bidens pilosa L. (Asteraceae), represent a potential alternative for the treatment of mucositis given its anti-inflammatory properties. In this study, B. pilosa glycolic extract was formulated (BPF) with poloxamer, a mucoadhesive copolymer, was used for treatment of 5-fluorouracil (5-FU)-induced mucositis in mice. As expected, animals only treated with 5-FU (200 mg/kg) presented marked weight loss, reduction of intestinal villi, crypts and muscular layer, which was associated with severe disruption of crypts, edema, inflammatory infiltrate and vacuolization in the intestinal tissue, as compared to the control group and healthy animals only treated with BPF. On the other hand, the treatment of intestinal mucositis-bearing mice with BPF (75, 100 or 125 mg/kg) managed to mitigate clinical and pathologic changes, noticeably at 100 mg/kg. This dose led to the restoration of intestinal proliferative activity through increasing Ki-67 levels; modulated the expression of Bax, Bcl2 and p53 apoptotic markers protecting intestinal cells from cell death. Moreover, this treatment regulated lipid peroxidation and inflammatory infiltration. No acute toxic effects were observed with this formulation. This work demonstrated that BPF was safe and effective against 5-FU-induced intestinal mucositis in mice. Additional studies are already in progress to further characterize the mechanisms involved in the protective effects of this technological formulation toward the development of a new medicine for the prevention and treatment of intestinal injury in patients undergoing chemotherapy/radiotherapy.

Nanotechnology in the treatment of inflammatory bowel diseases

BACKGROUND AND AIMS

Treatment of inflammatory bowel diseases (IBD) is only aimed to block or inhibit the pathogenetic steps of the inflammatory cascade. Side effects of systemic therapies, poor targeting of orally administered topical drug and low adherence to prescription represent frequent therapeutic challenges. Recent observations suggest that nanotechnology could provide amazing advantage in this field since particles having dimension in the nanometer scale (nanoparticles) can modify pharmacokinetic step of biologic and conventional therapeutic agents with a better delivery of drugs within the intestinal inflammatory cells. The aim of this review was to provide the clinician with an insight into the potential role of nanotechnology in the treatment of IBD.

METHODS

A systematic search (PubMed) for experimental studies on the treatment of intestinal inflammation using nanotechnology for the delivery of drugs.

RESULTS AND CONCLUSIONS

The size of the pharmaceutical formulation is inversely related to specificity for inflammation. Nanoparticles can penetrate epithelial and inflammatory cells resulting in much higher, effective and long-acting concentrations than can be obtained using conventional delivery systems. From a practical point of view, this should lead to improvements in both efficacy and adherence to treatment, providing patients with the prospect of stable and prolonged remissions with reduced drug loadings. Reduced systemic side effects could also be expected.

Review of natural products actions on cytokines in inflammatory bowel disease

The purpose of this review is to provide an overview of the effects that natural products have on inflammatory bowel disease (IBD) and to provide insight into the relationship between these natural products and cytokines modulation. More than 100 studies from the past 10 years were reviewed herein on the therapeutic approaches for treating IBD. The natural products having anti-IBD actions included phytochemicals, antioxidants, microorganisms, dietary fibers, and lipids. The literature revealed that many of these natural products exert anti-IBD activity by altering cytokine production. Specifically, phytochemicals such as polyphenols or flavonoids are the most abundant, naturally occurring anti-IBD substances. The anti-IBD effects of lipids were primarily related to the n-3 polyunsaturated fatty acids. The anti-IBD effects of phytochemicals were associated with modulating the levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1, IL-6, inducible nitric oxide synthase, and myeloperoxide. The anti-IBD effects of dietary fiber were mainly mediated via peroxisome proliferator-activated receptor-γ, TNF-α, nitric oxide, and IL-2, whereas the anti-IBD effects of lactic acid bacteria were reported to influence interferon-γ, IL-6, IL-12, TNF-α, and nuclear factor-κ light-chain enhancer of activated B cells. These results suggest that the anti-IBD effects exhibited by natural products are mainly caused by their ability to modulate cytokine production. However, the exact mechanism of action of natural products for IBD therapy is still unclear. Thus, future research is needed to examine the effect of these natural products on IBD and to determine which factors are most strongly correlated with reducing IBD or controlling the symptoms of IBD.