Enhanced colonic delivery of ciclosporin A self-emulsifying drug delivery system encapsulated in coated minispheres

Advances in colon-targeted drug technologies

PURPOSE OF REVIEW

Herein, we present an overview of innovative oral technologies utilized in colonic drug delivery systems that have made significant translational and clinical advancements to treat inflammatory bowel disease (IBD) in recent years.

RECENT FINDINGS

The colon is home to distinct physiological conditions, such as pH and microbiota, that have been exploited in the development of colonic drug delivery systems for the treatment of local and systemic diseases. However, given the intra and interindividual variability in the gastrointestinal tract of both healthy and diseased states, various systems have shown inconsistencies in targeted drug release to the colon. Recent breakthroughs have led to systems that incorporate multiple independent trigger mechanisms, ensuring drug release even if one mechanism fails due to physiological variability. Such advanced platforms have bolstered the development of oral biologics delivery, an especially promising direction given the lack of commercially available oral antibody medications for IBD. These concepts can be further enhanced by employing 3D printing which enables the personalisation of medicines.

SUMMARY

Leveraging these novel technologies can accurately deliver therapeutics to the colon, allowing for treatments beyond gastrointestinal tract diseases. To realize the full potential of colonic drug delivery, it is paramount that research focuses on the clinical translatability and scalability of novel concepts.

"Enhancing Oral Drug Absorption: Overcoming Physiological and Pharmaceutical Barriers for Improved Bioavailability"

The oral route stands out as the most commonly used method for drug administration, prized for its non-invasive nature, patient compliance, and easy administration. Several elements influence the absorption of oral medications, including their solubility, permeability across mucosal membranes, and stability within the gastrointestinal (GI) environment. Research has delved into comprehending physicochemical, biochemical, metabolic, and biological obstacles that impact the bioavailability of a drug. To improve oral drug absorption, several pharmaceutical technologies and delivery methods have been studied, including cyclodextrins, micelles, nanocarriers, and lipid-based carriers. This review examines both traditional and innovative drug delivery methods, as well as the physiological and pharmacological barriers influencing medication bioavailability when taken orally. Additionally, it describes the challenges and advancements in developing formulations suitable for oral use.

Exploring LIPIDs for their potential to improves bioavailability of lipophilic drugs candidates: A review

This review aims to provide a thorough examination of the benefits, challenges, and advancements in utilizing lipids for more effective drug delivery, ultimately contributing to the development of innovative approaches in pharmaceutical science. Lipophilic drugs, characterized by low aqueous solubility, present a formidable challenge in achieving effective delivery and absorption within the human body. To address this issue, one promising approach involves harnessing the potential of lipids. Lipids, in their diverse forms, serve as carriers, leveraging their unique capacity to enhance solubility, stability, and absorption of these challenging drugs. By facilitating improved intestinal solubility and selective lymphatic absorption of porously permeable drugs, lipids offer an array of possibilities for drug delivery. This versatile characteristic not only bolsters the pharmacological efficacy of drugs with low bioavailability but also contributes to enhanced therapeutic performance, ultimately reducing the required dose size and associated costs. This comprehensive review delves into the strategic formulation approaches that employ lipids as carriers to ameliorate drug solubility and bioavailability. Emphasis is placed on the critical considerations of lipid type, composition, and processing techniques when designing lipid-based formulations. This review meticulously examines the multifaceted challenges that come hand in hand with lipid-based formulations for lipophilic drugs, offering an insightful perspective on future trends. Regulatory considerations and the broad spectrum of potential applications are also thoughtfully discussed. In summary, this review presents a valuable repository of insights into the effective utilization of lipids as carriers, all aimed at elevating the bioavailability of lipophilic drugs.

Modulation of the gut microbiome with nisin

Nisin is a broad spectrum bacteriocin used extensively as a food preservative that was identified in Lactococcus lactis nearly a century ago. We show that orally-ingested nisin survives transit through the porcine gastrointestinal tract intact (as evidenced by activity and molecular weight determination) where it impacts both the composition and functioning of the microbiota. Specifically, nisin treatment caused a reversible decrease in Gram positive bacteria, resulting in a reshaping of the Firmicutes and a corresponding relative increase in Gram negative Proteobacteria. These changes were mirrored by the modification in relative abundance of pathways involved in acetate, butyrate (decreased) and propionate (increased) synthesis which correlated with overall reductions in short chain fatty acid levels in stool. These reversible changes that occur as a result of nisin ingestion demonstrate the potential of bacteriocins like nisin to shape mammalian microbiomes and impact on the functionality of the community.

Fundamental Aspects of Lipid-Based Excipients in Lipid-Based Product Development

Poor aqueous solubility of drugs is still a foremost challenge in pharmaceutical product development. The use of lipids in designing formulations provides an opportunity to enhance the aqueous solubility and consequently bioavailability of drugs. Pre-dissolution of drugs in lipids, surfactants, or mixtures of lipid excipients and surfactants eliminate the dissolution/dissolving step, which is likely to be the rate-limiting factor for oral absorption of poorly water-soluble drugs. In this review, we exhaustively summarize the lipids excipients in relation to their classification, absorption mechanisms, and lipid-based product development. Methodologies utilized for the preparation of solid and semi-solid lipid formulations, applications, phase behaviour, and regulatory perspective of lipid excipients are discussed.

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.

In Vitro Methodologies for Evaluating Colon-Targeted Pharmaceutical Products and Industry Perspectives for Their Applications

Several locally acting colon-targeted products to treat colonic diseases have been recently developed and marketed, taking advantage of gastrointestinal physiology to target delivery. Main mechanisms involve pH-dependent, time-controlled and/or enzymatic-triggered release. With site of action located before systemic circulation and troublesome colonic sampling, there is room for the introduction of meaningful in vitro methods for development, quality control (QC) and regulatory applications of these formulations. A one-size-fits-all method seems unrealistic, as the selection of experimental conditions should resemble the physiological features exploited to trigger the release. This article reviews the state of the art for bio-predictive dissolution testing of colon-targeted products. Compendial methods overlook physiological aspects, such as buffer molarity and fluid composition. These are critical for pH-dependent products and time-controlled systems containing ionizable drugs. Moreover, meaningful methods for enzymatic-triggered products including either bacteria or enzymes are completely ignored by pharmacopeias. Bio-predictive testing may accelerate the development of successful products, although this may require complex methodologies. However, for high-throughput routine testing (e.g., QC), simplified methods can be used where balance is struck between simplicity, robustness and transferability on one side and bio-predictivity on the other. Ultimately, bio-predictive methods can occupy a special niche in terms of supplementing plasma concentration data for regulatory approval.

pH-Responsive Alginate-Based Microparticles for Colon-Targeted Delivery of Pure Cyclosporine A Crystals to Treat Ulcerative Colitis

Cyclosporine A (CsA) is a potent immunosuppressant for treating ulcerative colitis (UC). However, owing to severe systemic side effects, CsA application in UC therapy remains limited. Herein, a colon-targeted drug delivery system consisting of CsA crystals (CsAc)-loaded, Eudragit S 100 (ES)-coated alginate microparticles (CsAc-EAMPs) was established to minimize systemic side effects and enhance the therapeutic efficacy of CsA. Homogeneously-sized CsAs (3.1 ± 0.9 μm) were prepared by anti-solvent precipitation, followed by the fabrication of 47.1 ± 6.5 μm-sized CsAc-EAMPs via ionic gelation and ES coating. CsAc-EAMPs exhibited a high drug loading capacity (48 ± 5%) and a CsA encapsulation efficacy of 77 ± 9%. The in vitro drug release study revealed that CsA release from CsAc-EAMPs was suppressed under conditions simulating the stomach and small intestine, resulting in minimized systemic absorption and side effects. Following exposure to the simulated colon conditions, along with ES dissolution and disintegration of alginate microparticles, CsA was released from CsAc-EAMPs, exhibiting a sustained-release profile for up to 24 h after administration. Given the effective colonic delivery of CsA molecules, CsAc-EAMPs conferred enhanced anti-inflammatory activity in mouse model of dextran sulfate sodium (DSS)-induced colitis. These findings suggest that CsAc-EAMPs is a promising drug delivery system for treating UC.

Pectin based multi-particulate carriers for colon-specific delivery of therapeutic agents

In case of colon-specific delivery of therapeutic agents through oral route, microbial/enzyme-triggered release approach has several advantages over other approaches due to unique microbial ecosystem in the colon. Multiple-unit carriers have an edge over single-unit carriers for this purpose. Among different materials/polymers explored, pectin appears as a promising biopolymer to construct microbial-triggered colon-specific carriers. Pectin is specifically degraded by colonic enzymes but insusceptible to upper gastro-intestinal enzymes. In this article, utilization of pectin solely or in combination with other polymers and/or colonic-delivery approaches is critically discussed in detail in the context of multi-particulate systems. Several studies showed that pectin-based carriers can prevent the release of payload in the stomach but start to release in the intestine. Hence, pectin alone may construct delayed release formulation but may not be sufficient for effective colon-targeting. On the other hand, combination of pectin with other materials/polymers (e.g., chitosan and Eudragit® S-100) has demonstrated huge promise for colon-specific release of payload. Hence, smartly designed pectin-based multi-particulate carriers, especially in combination with other polymers and/or colon-targeting approaches (e.g., microbial-triggered + pH-triggered or microbial-triggered + pH-triggered + time-release or microbial-triggered + pH-triggered + pressure-based), can be successful colon-specific delivery systems. However, more clinical trials are necessary to bring this idea from bench to bedside.

Drug delivery formulation impacts cyclosporine efficacy in a humanised mouse model of acute graft versus host disease

Acute graft versus host disease (aGvHD) is an allogeneic T cell mediated disease which manifests as a severe inflammatory disease affecting multiple organs including the liver, skin, lungs and gastrointestinal tract. Existing prophylactic and therapeutic approaches in aGvHD include the use of cyclosporine A (CyA), however the currently approved CyA formulations which were designed to optimise systemic CyA bioavailability can have a number of side effects including nephrotoxicity as well as the potential to attenuate the beneficial Graft-versus-Leukemia (GvL) effect. An added complication with CyA is that it has a narrow therapeutic window, and following oral administration is absorbed only from the small intestine, with variable cytochrome P450 metabolism contributing to intra- and inter-patient variability. This study sought to investigate the efficacy of a novel CyA oral formulation enabled by the integrated SmPill® oral drug delivery platform in a humanised mouse model of aGvHD. The study compared the approved optimised CyA (Neoral®) with SmPill®-enabled CyA and a systemic intravenous CyA formulation. Our findings clearly demonstrate superior efficacy of the novel SmPill® CyA in prolonging survival in a clinically relevant humanised aGvHD model. SmPill® CyA significantly reduced pathological score in the small intestine, colon, liver and lung of aGvHD mice. In addition, SmPill® CyA significantly reduced the levels of pro-inflammatory cytokines in all the GvHD target tissues examined. Notably, SmPill® CyA was significantly more potent in reducing GvHD associated pathology and inflammatory cytokine production compared to the optimised approved oral CyA formulation, Neoral®.

Encapsulated cyclosporine does not change the composition of the human microbiota when assessed ex vivo and in vivo

Introduction. Management of steroid-refractory ulcerative colitis has predominantly involved treatment with systemic cyclosporine A (CyA) and infliximab.Aim. The purpose of this study was to assess the effect of using a colon-targeted delivery system CyA formulation on the composition and functionality of the gut microbiota.Methodology. Ex vivo faecal fermentations from six healthy control subjects were treated with coated minispheres (SmPill) with (+) or without (-) CyA and compared with a non-treated control in a model colon system. In addition, the in vivo effect of the SmPill+CyA formulation was investigated by analysing the gut microbiota in faecal samples collected before the administration of SmPill+CyA and after 7 consecutive days of administration from eight healthy subjects who participated in a pilot study.Results. Analysis of faecal samples by 16S rRNA gene sequencing indicated little variation in the diversity or relative abundance of the microbiota composition before or after treatment with SmPill minispheres with or without CyA ex vivo or with CyA in vivo. Short-chain fatty acid profiles were evaluated using gas chromatography, showing an increase in the concentration of n-butyrate (P=0.02) and acetate (P=0.32) in the faecal fermented samples incubated in the presence of SmPill minispheres with or without CyA. This indicated that increased acetate and butyrate production was attributed to a component of the coated minispheres rather than an effect of CyA on the microbiota. Butyrate and acetate levels also increased significantly (P=0.05 for both) in the faecal samples of healthy individuals following 7 days' treatment with SmPill+CyA in the pilot study.Conclusion. SmPill minispheres with or without CyA at the clinically relevant doses tested here have negligible direct effects on the gut microbiota composition. Butyrate and acetate production increased, however, in the presence of the beads in an ex vivo model system as well as in vivo in healthy subjects. Importantly, this study also demonstrates the relevance and value of using ex vivo colon models to predict the in vivo impact of colon-targeted drugs directly on the gut microbiota.

Premium ethylcellulose polymer based architectures at work in drug delivery

Premium ethylcellulose polymers are hydrophobic cellulose ether based biomaterials widely employed as biocompatible templates for the design of novel drug delivery systems. They are classified as United States Food and Drug Administration Generally-Recognized-As-Safe chemical substances and have been extensively utilized within the biomedical and pharmaceutical industries for over half a century. They have so far demonstrated the potential to modulate and improve the physiological performance of bioactives leading to the desired enhanced prophylactic and therapeutic outcomes. This review therefore presents a scholarly survey of inter-disciplinary developments focused on the functionalities of ethylcellulose polymers as biomaterials useful for the design of smart delivery architectures for relevant pharmacotherapeutic biomedical applications. Emphasis was placed on evaluating scientific resources related to recent advancements and future directions associated with its applications as delivery systems for drugs and biologics within the past decade thus complementing other specialized reviews showcasing the theme.

Local delivery of macromolecules to treat diseases associated with the colon

Current treatments for intestinal diseases including inflammatory bowel diseases, irritable bowel syndrome, and colonic bacterial infections are typically small molecule oral dosage forms designed for systemic delivery. The intestinal permeability hurdle to achieve systemic delivery from oral formulations of macromolecules is challenging, but this drawback can be advantageous if an intestinal region is associated with the disease. There are some promising formulation approaches to release peptides, proteins, antibodies, antisense oligonucleotides, RNA, and probiotics in the colon to enable local delivery and efficacy. We briefly review colonic physiology in relation to the main colon-associated diseases (inflammatory bowel disease, irritable bowel syndrome, infection, and colorectal cancer), along with the impact of colon physiology on dosage form design of macromolecules. We then assess formulation strategies designed to achieve colonic delivery of small molecules and concluded that they can also be applied some extent to macromolecules. We describe examples of formulation strategies in preclinical research aimed at colonic delivery of macromolecules to achieve high local concentration in the lumen, epithelial-, or sub-epithelial tissue, depending on the target, but with the benefit of reduced systemic exposure and toxicity. Finally, the industrial challenges in developing macromolecule formulations for colon-associated diseases are presented, along with a framework for selecting appropriate delivery technologies.

Pharmaceutical Dispersion Techniques for Dissolution and Bioavailability Enhancement of Poorly Water-Soluble Drugs

Over the past decades, a large number of drugs as well as drug candidates with poor dissolution characteristics have been witnessed, which invokes great interest in enabling formulation of these active ingredients. Poorly water-soluble drugs, especially biopharmaceutical classification system (BCS) II ones, are preferably designed as oral dosage forms if the dissolution limit can be broken through. Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This article reviews the most commonly used dispersion techniques for pharmaceutical processing that can practically enhance the dissolution and bioavailability of poorly water-soluble drugs. Major interests focus on solid dispersion, lipid-based dispersion (nanoencapsulation), and liquisolid dispersion (drug solubilized in a non-volatile solvent and dispersed in suitable solid excipients for tableting or capsulizing), covering the formulation development, preparative technique and potential applications for oral drug delivery. Otherwise, some other techniques that can increase the dispersibility of a drug such as co-precipitation, concomitant crystallization and inclusion complexation are also discussed. Various dispersion techniques provide a productive platform for addressing the formulation challenge of poorly water-soluble drugs. Solid dispersion and liquisolid dispersion are most likely to be successful in developing oral dosage forms. Lipid-based dispersion represents a promising approach to surmounting the bioavailability of low-permeable drugs, though the technique needs to traverse the obstacle from liquid to solid transformation. Novel dispersion techniques are highly encouraged to develop for formulation of poorly water-soluble drugs.

The pig as a preclinical model for predicting oral bioavailability and in vivo performance of pharmaceutical oral dosage forms: a PEARRL review

OBJECTIVES

In pharmaceutical drug development, preclinical tests in animal models are essential to demonstrate whether the new drug is orally bioavailable and to gain a first insight into in vivo pharmacokinetic parameters that can subsequently be used to predict human values. Despite significant advances in the development of bio-predictive in vitro models and increasing ethical expectations for reducing the number of animals used for research purposes, there is still a need for appropriately selected pre-clinical in vivo testing to provide guidance on the decision to progress to testing in humans. The selection of the appropriate animal models is essential both to maximise the learning that can be obtained from such experiments and to avoid unnecessary testing in a range of species.

KEY FINDINGS

The present review, provides an insight into the suitability of the pig model for predicting oral bioavailability in humans, by comparing the conditions in the GIT. It also contains a comparison between the bioavailability of compounds dosed to both humans and pigs, to provide an insight into the relative correlation and examples on why a lack of correlation may be observed.

SUMMARY

While there is a general trend towards predicting human bioavailability from pig data, there is considerable variability in the data set, most likely reflecting species specific differences in individual drug metabolism. Nonetheless, the correlation between pigs vs. humans was comparable to that reported for dogs vs. humans. The presented data demonstrate the suitability of the pig as a preclinical model to predict bioavailability in human.

Comparison Of iNfliximab and ciclosporin in STeroid Resistant Ulcerative Colitis: pragmatic randomised Trial and economic evaluation (CONSTRUCT)

BACKGROUND

The efficacy of infliximab and ciclosporin in treating severe ulcerative colitis (UC) is proven, but there has been no comparative evaluation of effectiveness.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of infliximab and ciclosporin in treating steroid-resistant acute severe UC.

METHOD

Between May 2010 and February 2013 we recruited 270 participants from 52 hospitals in England, Scotland and Wales to an open-label parallel-group, pragmatic randomised trial. Consented patients admitted with severe colitis completed baseline quality-of-life questionnaires before receiving intravenous hydrocortisone. If they failed to respond within about 5 days, and met other inclusion criteria, we invited them to participate and used a web-based adaptive randomisation algorithm to allocate them in equal proportions between 5 mg/kg of intravenous infliximab at 0, 2 and 6 weeks or 2 mg/kg/day of intravenous ciclosporin for 7 days followed by 5.5 mg/kg/day of oral ciclosporin until 12 weeks from randomisation. Further treatment was at the discretion of physicians responsible for clinical management. The primary outcome was quality-adjusted survival (QAS): the area under the curve (AUC) of scores derived from Crohn's and Ulcerative Colitis Questionnaires completed by participants at 3 and 6 months, and then 6-monthly over 1-3 years, more frequently after surgery. Secondary outcomes collected simultaneously included European Quality of Life-5 Dimensions (EQ-5D) scores and NHS resource use to estimate cost-effectiveness. Blinding was possible only for data analysts. We interviewed 20 trial participants and 23 participating professionals. Funded data collection finished in March 2014. Most participants consented to complete annual questionnaires and for us to analyse their routinely collected health data over 10 years.

RESULTS

The 135 participants in each group were well matched at baseline. In 121 participants analysed in each group, we found no significant difference between infliximab and ciclosporin in QAS [mean difference in AUC/day 0.0297 favouring ciclosporin, 95% confidence interval (CI) -0.0088 to 0.0682; p = 0.129]; EQ-5D scores (quality-adjusted life-year mean difference 0.021 favouring ciclosporin, 95% CI -0.032 to 0.096; p = 0.350); Short Form questionnaire-6 Dimensions scores (mean difference 0.0051 favouring ciclosporin, 95% CI -0.0250 to 0.0353; p = 0.737). There was no statistically significant difference in colectomy rates [odds ratio (OR) 1.350 favouring infliximab, 95% CI 0.832 to 2.188; p = 0.223]; numbers of serious adverse reactions (event ratio = 0.938 favouring ciclosporin, 95% CI 0.590 to 1.493; p = 0.788); participants with serious adverse reactions (OR 0.660 favouring ciclosporin, 95% CI 0.282 to 1.546; p = 0.338); numbers of serious adverse events (event ratio 1.075 favouring infliximab, 95% CI 0.603 to 1.917; p = 0.807); participants with serious adverse events (OR 0.999 favouring infliximab, 95% CI 0.473 to 2.114; p = 0.998); deaths (all three who died received infliximab; p = 0.247) or concomitant use of immunosuppressants. The lower cost of ciclosporin led to lower total NHS costs (mean difference -£5632, 95% CI -£8305 to -£2773; p < 0.001). Interviews highlighted the debilitating effect of UC; participants were more positive about infliximab than ciclosporin. Professionals reported advantages and disadvantages with both drugs, but nurses disliked the intravenous ciclosporin.

CONCLUSIONS

Total cost to the NHS was considerably higher for infliximab than ciclosporin. Nevertheless, there was no significant difference between the two drugs in clinical effectiveness, colectomy rates, incidence of SAEs or reactions, or mortality, when measured 1-3 years post treatment. To assess long-term outcome participants will be followed up for 10 years post randomisation, using questionnaires and routinely collected data. Further studies will be needed to evaluate the efficacy and effectiveness of new anti-tumour necrosis factor drugs and formulations of ciclosporin.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN22663589.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 44. See the NIHR Journals Library website for further project information.

Sustained-release multiparticulates for oral delivery of a novel peptidic ghrelin agonist: Formulation design and in vitro characterization

There is an impetus to provide appropriate sustained release oral delivery vehicles to protect biofunctional peptide loads from gastric degradation in vivo. This study describes the generation of a high load capacity pellet formulation for sustained release of a freely water-soluble dairy-derived hydrolysate, FHI-2571. The activity of this novel peptidic ghrelin receptor agonist is reported using in vitro calcium mobilization assays. Conventional extrusion spheronization was then used to prepare peptide-loaded pellets which were subsequently coated with ethylcellulose (EC) film coats using a fluid bed coating system in bottom spray (Wurster) mode. Aqueous-based EC coating dispersions produced mechanically brittle coats which fractured due to osmotic pressure build-up within pellets in simulated media. In contrast, an ethanolic-based EC coating solution provided robust, near zero-order release in both USP Type 1 and Type 4 dissolution studies. Interestingly, the functionality of aqueous-based EC film coats was restored by first layering pellets with a methacrylic acid copolymer (MA) subcoat, thereby hindering pellet core swelling in acidic media. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) was utilised as a complementary technique to confirm the results seen in USP dissolution studies. Retention of activity of the ghrelinergic peptide hydrolysate in the final encapsulated product was confirmed as being greater than 80%. The described pellet formulation is amenable to oral dosing in small animal studies in order to assess in vivo efficacy of the whey-derived ghrelinergic hydrolysate. In more general terms, it is also suitable as a delivery vehicle for peptide-based bioactives to special population groups e.g paediatric and geriatric.

Thermostability of the coating, antigen and immunostimulator in an adjuvanted oral capsule vaccine formulation

Oral vaccines present an attractive alternative to injectable vaccines for enteric diseases due to ease of delivery and the induction of intestinal immunity at the site of infection. However, susceptibility to gastrointestinal proteolysis, limited transepithelial uptake and a lack of clinically acceptable adjuvants present significant challenges. A further challenge to mass vaccination in developing countries is the very expensive requirement to maintain the cold chain. We recently described the effectiveness of a Single Multiple Pill^® (SmPill^®) adjuvanted capsule approach to enhance the effectiveness of a candidate enterotoxigenic Escherichia coli (ETEC) oral vaccine. Here it was demonstrated that this delivery system maintains the antigenicity of ETEC colonisation factor antigen I (CFA/I) and the immunostimulatory activity of the orally active α-Galactosylceramide (α-GalCer) adjuvant after storage of SmPill^® minispheres under room temperature and extreme storage conditions for several months. In addition, the internal structure of the cores of SmPill^® minispheres and antigen release features at intestinal pH were found to be preserved under all these conditions. However, changes in the surface morphology of SmPill^® minispheres leading to the antigen release at gastric pH were observed after a few weeks of storage under extreme conditions. Those modifications were prevented by the introduction of an Opadry^® White film coating layer between the core of SmPill^® minispheres and the enteric coating. Under these conditions, protection against antigen release at gastric pH was maintained even under high temperature and humidity conditions. These results support the potential of the SmPill^® minisphere approach to maintain the stability of an adjuvanted whole cell killed oral vaccine formulation.

Current status of selected oral peptide technologies in advanced preclinical development and in clinical trials

The development of oral dosage forms that allows absorption of therapeutic peptides to the systemic circulation is one of the greatest challenges for the pharmaceutical industry. Currently, a number of technologies including either mixtures of penetration enhancers or protease inhibitors and/or nanotechnology-based products are under clinical development. Typically, these formulations are presented in the form of enteric-coated tablets or capsules. Systems undergoing preclinical investigation include further advances in nanotechnology, including intestinal microneedle patches, as well as their combination with regional delivery to the colon. This review critically examines four selected promising oral peptide technologies at preclinical stage and the twelve that have progressed to clinical trials, as indicated in www.clinicaltrials.gov. We examined these technologies under the criteria of peptide selection, formulation design, system components and excipients, intestinal mechanism of action, efficacy in man, and safety issues. The conclusion is that most of the technologies in clinical trials are incremental rather than paradigm-shifting and that even the more clinically advanced oral peptide drugs examples of oral bioavailability appear to yield oral bioavailability values of only 1-2% and are, therefore, only currently suitable for a limited range of peptides.

Infliximab versus ciclosporin for steroid-resistant acute severe ulcerative colitis (CONSTRUCT): a mixed methods, open-label, pragmatic randomised trial

BACKGROUND

Infliximab and ciclosporin are of similar efficacy in treating acute severe ulcerative colitis, but there has been no comparative evaluation of their relative clinical effectiveness and cost-effectiveness.

METHODS

In this mixed methods, open-label, pragmatic randomised trial, we recruited consenting patients aged 18 years or older at 52 district general and teaching hospitals in England, Scotland, and Wales who had been admitted, unscheduled, with severe ulcerative colitis and failed to respond to intravenous hydrocortisone within about 5 days. Patients were randomly allocated (1:1) to receive either infliximab (5 mg/kg intravenous infusion given over 2 h at baseline, and again at 2 weeks and 6 weeks after the first infusion) or ciclosporin (2 mg/kg per day by continuous infusion for up to 7 days, followed by twice-daily tablets delivering 5·5 mg/kg per day for 12 weeks). Randomisation used a web-based password-protected site, with a dynamic algorithm to generate allocations on request, thus protecting against investigator preference or other subversion, while ensuring that each trial group was balanced by centre, which was the only stratification used. Local investigators and participants were aware of the treatment allocated, but the chief investigator and analysts were masked. Analysis was by treatment allocated. The primary outcome was quality-adjusted survival-ie, the area under the curve (AUC) of scores from the Crohn's and Ulcerative Colitis Questionnaire (CUCQ) completed by participants at baseline, 3 months, and 6 months, then every 6 months from 1 year to 3 years. This trial is registered with the ISRCTN Registry, number ISRCTN22663589.

FINDINGS

Between June 17, 2010, and Feb 26, 2013, 270 patients were recruited. 135 patients were allocated to the infliximab group and 135 to the ciclosporin group. 121 (90%) patients in each group were included in the analysis of the primary outcome. There was no significant difference between groups in quality-adjusted survival (mean AUC 564·0 [SD 241·9] in the infliximab group vs 587·0 [226·2] in the ciclosporin group; mean adjusted difference 7·9 [95% CI -22·0 to 37·8]; p=0·603). Likewise, there were no significant differences between groups in the secondary outcomes of CUCQ scores, EQ-5D, or SF-6D scores; frequency of colectomy (55 [41%] of 135 patients in the infliximab group vs 65 [48%] of 135 patients in the ciclosporin group; p=0·223); or mean time to colectomy (811 [95% CI 707-912] days in the infliximab group vs 744 [638-850] days in the ciclosporin group; p=0·251). There were no differences in serious adverse reactions (16 reactions in 14 participants receiving infliximab vs ten in nine patients receiving ciclosporin); serious adverse events (21 in 16 patients vs 25 in 17 patients); or deaths (three in the infliximab group vs none in the ciclosporin group).

INTERPRETATION

There was no significant difference between ciclosporin and infliximab in clinical effectiveness.

FUNDING

NIHR Health Technology Assessment programme.