5-ASA colonic mucosal concentrations resulting from different pharmaceutical formulations in ulcerative colitis

Downregulation of OATP2B1 by proinflammatory cytokines leads to 5-ASA hyposensitivity in Ulcerative colitis

5-Aminosalicylic acid (5-ASA) is a first-line agent in both remission and maintenance therapy for ulcerative colitis (UC). However, the mucosal concentration of 5-ASA was significantly lower in patients with severe histological inflammation, which further led to a poor response to 5-ASA treatment. Our study aimed to clarify the mechanism of 5-ASA uptake into colonic epithelial cells and to further explore the reason for the decreased colonic mucosal 5-ASA concentration in UC patients. Our results demonstrated that the colonic 5-ASA concentration was notably reduced in DSS-induced colitis mice and inversely correlated with colonic inflammation. 5-ASA was not a substrate of carnitine/organic cation transporter 1/2 (OCTN1/2) or multidrug resistance protein 1 (MDR1), whereas organic anion transporting polypeptide 2B1 (OATP2B1) and sodium-coupled monocarboxylate transporter 1 (SMCT1) mediated the uptake of 5-ASA, with a greater contribution from OATP2B1 than SMCT1. Inhibitors and siRNAs targeting OATP2B1 significantly reduced 5-ASA absorption in colonic cell lines. Moreover, OATP2B1 expression was dramatically downregulated in colon tissues from UC patients and dextran sodium sulfate (DSS)-induced colitis mice, and was also negatively correlated with colonic inflammation. Mechanistically, mixed proinflammatory cytokines downregulated the expression of OATP2B1 in a time- and concentration-dependent manner through the hepatocyte nuclear factor 4 α (HNF4α) pathway. In conclusion, OATP2B1 was the pivotal transporter involved in colonic 5-ASA uptake, which indicated that inducing OATP2B1 expression may be a strategy to promote 5-ASA uptake and further improve the concentration and anti-inflammatory efficacy of 5-ASA in UC.

Oral Drug Delivery Systems Applied to Launched Products: Value for the Patients and Industrial Considerations

Drug delivery systems (DDS) control the amount, rate, and site of administration of drug substances in the body as well as their release and ADME (absorption, distribution, metabolism, excretion). Among the various types of DDS, amount-controlled DDS for solubilization and absorption increase the bioavailability. Time- and amount-controlled DDS are controlled release formulations classified as (1) membrane-type, (2) matrix-type, (3) osmotic-type, and (4) ion-exchange type. Timed-release formulations also control the time and amount of release and the absorption of drugs. Site- and amount-controlled DDS are characterized by colonic delivery and intestinal lymph-targeting to improve release and ADME of drug substances. Finally, site-, time-, and amount-controlled DDS are gastroretentive formulations and local delivery in the oral cavity to improve site retention, release, and ADME of drugs. DDS can enhance efficacy, reduce adverse effects, and optimize the dosing frequency of various drug products to increase patient value. This review focuses on patient value and industrial considerations of launched oral DDS. We provide a technological overview of candidate and marketed DDS, as well as the pros/cons of the technologies for industrialization with consideration to excipients, manufacturing, and storage stability. Moreover, to demonstrate the usefulness of the technology and support the selection and development of the best technologies for patients, we also describe patient value from clinical studies and analyses, particularly with regard to increased new medical options, higher efficacy, reduced adverse effects, reduced number of doses and clinic visits, easier administration, higher quality of life, greater adherence, and satisfaction.

Potential of Mesalazine Therapeutic Drug Monitoring by Measuring Fecal Excretion in Patients With Ulcerative Colitis

BACKGROUND

Therapeutic drug monitoring of mesalazine (5-ASA) in patients with ulcerative colitis is unavailable. Mucosal 5-ASA concentrations are assumed to be higher during remission, but biopsy is not practical. Therefore, we investigated the feasibility of measuring mesalazine levels in feces. To explore the potential role of fecal mesalazine measurements in therapeutic drug monitoring, we compared the dry fecal concentration and daily fecal excretion of 5-ASA and its metabolite N-acetyl-5-ASA in patients with ulcerative colitis with active and quiescent disease.

METHODS

Adults with ulcerative colitis on oral mesalazine and scheduled for colonoscopy were eligible for inclusion in this cross-sectional study. Stool and urine samples were collected for 48 and 24 hours, respectively, and rectal biopsies were performed. (N-acetyl-)5-ASA was measured using mass spectrometry. Biochemically active disease was defined as a fecal calprotectin level above 100 mcg/g and endoscopically active disease as any activity following the endoscopic Mayo score (≥1).

RESULTS

Approximately 28 patients were included in the study. Daily fecal excretion of (N-acetyl-)5-ASA did not differ between patients with (n = 13) and without (n = 15) endoscopically active disease [median 572 mg/d versus 597 mg/d ( P = 0.86) for 5-ASA and 572 mg/d versus 554 mg/d ( P = 0.86) for N-acetyl-5-ASA]. The same applied to the fecal concentration [median 9.7 mcg/mg dry weight versus 10.3 ( P = 0.53) and 12.0 versus 9.9 ( P = 0.89)]. The results were comparable when the biochemical disease activity definition was used. The mucosal concentrations and urinary excretion of (N-acetyl-)5-ASA did not differentiate between quiescent and active activity.

CONCLUSIONS

Fecal (N-acetyl-)5-ASA measurements do not correlate with disease activity, which renders it an unsuitable tool for therapeutic drug monitoring of mesalazine.

pH-dependent vs. constant release of mesalazine in the treatment of ulcerative colitis: Do drug delivery concepts determine therapeutic efficacy? (Review)

Inflammatory bowel diseases (IBD) have developed to become a major global health problem. Ulcerative colitis (UC) is one of two main types of IBD, and >90% of patients suffering from mild or moderate forms of UC are treated with mesalazine, a well-tolerated and cost-effective drug. To allow oral administration, the drug has to be protected from resorption before it can reach the affected sites in the colon. The drug is therefore released from most currently used medications either constantly slow (time-dependent) or triggered by an increased pH during gastrointestinal transition. Both variants are widely used in clinical practice and it is surprising that they have not yet been compared directly in a large clinical study. In this overview, the evidence that may suggest preferential use of one type of mesalazine formulation over the other in general or for defined subgroups of patients is summarized and evaluated. Data from in vitro modelling of drug release and measurements of drug concentrations in colonic mucosa suggest that in many cases, constant release and pH-dependent formulations are of similar therapeutic efficiency; however, pH-triggered release may be superior in patients with proctitis-type UC or sites of inflammation in the proximal colon. Additionally, patients with a long gastric residence time, slow small intestinal transition, disease-related diarrhea or sensitivity to systemic adverse effects may benefit more from pH-dependent release formulations. In general, medications based on both concepts show similar efficacies, but the pH-dependent release formulations seem to be more robust in the treatment of a not further classified group of patients with UC. Future comparative clinical studies are required to clearly define the subgroups of patients that should be treated preferably with constant or pH-dependent release formulations of mesalazine.

Differential effects of mesalazine formulations on thiopurine metabolism through thiopurine S-methyltransferase inhibition

BACKGROUND AND AIM

Thiopurines are often used in combination with mesalazine for the treatment of ulcerative colitis (UC). Mesalazine formulations are delivered to the digestive tract by various delivery systems and absorbed as 5-aminosalicylic acid (5-ASA). 5-ASA is known to inhibit thiopurine S-methyltransferase (TPMT) activity and to affect thiopurine metabolism. There have been no studies comparing TPMT inhibition by multimatrix mesalazine (MMX) with other formulations. We investigated the difference in TPMT inhibition by different mesalazine formulations and prospectively confirmed the clinical relevance.

METHODS

Plasma concentrations of 5-ASA, N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA), and TPMT activities were measured in UC patients receiving various mesalazine formulations (time-dependent or pH-dependent mesalazine or MMX) as monotherapy. Patients already on both time-dependent or pH-dependent mesalazine and thiopurines switched their mesalazine to MMX, examining 6-thioguanine nucleotide (6-TGN) and 6-methylmercaptopurine (6-MMP) 0 and 8 weeks after switching. Clinical relapse after switching was also monitored for 24 weeks.

RESULTS

Plasma 5-ASA and N-Ac-5-ASA levels were significantly higher in patients receiving time-dependent mesalazine (n = 12) compared with pH-dependent mesalazine (n = 12) and MMX (n = 15), accompanied by greater TPMT inhibition. Prospective switching from time-dependent mesalazine to MMX decreased 6-TGN levels, increased those of 6-MMP, and increased 6-MMP/6-TGN ratios. Furthermore, this resulted in significantly more relapses than switching from pH-dependent mesalazine to MMX.

CONCLUSIONS

Time-dependent mesalazine has higher plasma 5-ASA and N-Ac-5-ASA levels and greater TPMT inhibition than MMX. Therefore, switching from time-dependent mesalazine to MMX may lead to an increase of 6-MMP/6-TGN, which may reduce the clinical effectiveness of thiopurines, warranting close monitoring after switch.

Factors associated with the persistence of oral 5-aminosalicylic acid monotherapy in ulcerative colitis: a nationwide Norwegian cohort study

BACKGROUND

Oral 5-aminosalicylic acid (5-ASA) is the mainstay treatment of ulcerative colitis (UC) and therapy with oral 5-ASA is associated with beneficial outcomes. We have examined factors associated with the persistence of oral 5-ASA treatment in a national cohort of UC patients.

METHODS

Patients with newly diagnosed UC from 2010 to 2014 using oral 5-ASA monotherapy were identified by combining data from the Norwegian Patient Registry and the Norwegian Prescription Database. The median follow-up time was 1029 days. Drug persistence was defined as duration of oral 5-ASA preparation as monotherapy. Non-persistence of a oral 5-ASA preparation as monotherapy was defined as stopping oral 5-ASA, initiation of any further anti-inflammatory treatment including a course of glucocorticoids and a change to another oral 5-ASA preparation. Drug persistence was analyzed using the Kaplan-Meier method and influence of covariates on drug persistence was analyzed with the Cox proportional hazard model.

RESULTS

A total of 3421 patients were identified. The overall median 5-ASA drug persistence was 179 days. In univariate analyses, persistence was associated with preparation type and high-dose treatment, while oral glucocorticoid use or hospitalization around the start of oral 5-ASA were associated with shorter 5-ASA persistence. In multivariate analyses, oral glucocorticoids [HR 1.67 (1.54-1.80), p < 0.005] and hospitalization around start of 5-ASA [HR 1.23 (1.14-1.34), p < 0.005] were associated with non-persistence, whereas high dose (⩾3 g/day) 5-ASA was associated with longer persistence [HR 0.68 (0.65-0.71), p < 0.005].

CONCLUSION

High-dose treatment with oral 5-ASA was associated with longer persistence of oral 5-ASA monotherapy, whereas the presence of factors indicating more severe disease around initiation of 5-ASA monotherapy was associated with a shorter persistence.

Paeoniflorin protects against dextran sulfate sodium (DSS)-induced colitis in mice through inhibition of inflammation and eosinophil infiltration

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers in the digestive tract. The treatment commonly includes anti-inflammatory agents like 5-aminosalicylic acid or corticosteroids or biologics for people with UC who are no longer responding to corticosteroids. The radices of Paeonia lactiflora Pall. or similar plants of the Paeonia genus have been used in Chinese medicine to treat certain diseases that resemble the symptoms of UC. Paeoniflorin, a terpenoid glycoside, is a major active component for the anti-inflammatory and antitumor activity. In this study, we evaluated the therapeutic effect of paeoniflorin (PF) against dextran sulfate sodium (DSS)-induced colitis in mice and found that PF exhibited protective activity against colitis. PF treatment suppressed NF-κB pathway activation, resulting down regulation of pro-inflammatory factor expression. In addition, we detected reduction in eosinophil-related chemokine gene expression and eosinophil infiltration. The treatment also reversed Treg cell population suppression. Although PF treatment did not block COX2 induction, the compound weakly inhibited COX2 activity in an enzymatic assay. Taken together, PF exerts its therapeutic activity against UC through inhibition of inflammation and eosinophil infiltration.

Oxidized phospholipids affect small intestine neuromuscular transmission and serotonergic pathways in juvenile mice

BACKGROUND

Oxidized phospholipid derivatives (OxPAPCs) act as bacterial lipopolysaccharide (LPS)-like damage-associated molecular patterns. OxPAPCs dose-dependently exert pro- or anti-inflammatory effects by interacting with several cellular receptors, mainly Toll-like receptors 2 and 4. It is currently unknown whether OxPAPCs may affect enteric nervous system (ENS) functional and structural integrity.

METHODS

Juvenile (3 weeks old) male C57Bl/6 mice were treated intraperitoneally with OxPAPCs, twice daily for 3 days. Changes in small intestinal contractility were evaluated by isometric neuromuscular responses to receptor and non-receptor-mediated stimuli. Alterations in ENS integrity and serotonergic pathways were assessed by real-time PCR and confocal immunofluorescence microscopy in longitudinal muscle-myenteric plexus whole-mount preparations (LMMPs). Tissue levels of serotonin (5-HT), tryptophan, and kynurenine were measured by HPLC coupled to UV/fluorescent detection.

KEY RESULTS

OxPAPC treatment induced enteric gliosis, loss of myenteric plexus neurons, and excitatory hypercontractility, and reduced nitrergic neurotransmission with no changes in nNOS⁺ neurons. Interestingly, these changes were associated with a higher functional response to 5-HT, altered immunoreactivity of 5-HT receptors and serotonin transporter (SERT) together with a marked decrease in 5-HT levels, shifting tryptophan metabolism toward kynurenine production.

CONCLUSIONS AND INFERENCES

OxPAPC treatment disrupted structural and functional integrity of the ENS, affecting serotoninergic tone and 5-HT tissue levels toward a higher kynurenine content during adolescence, suggesting that changes in intestinal lipid metabolism toward oxidation can affect serotoninergic pathways, potentially increasing the risk of developing functional gastrointestinal disorders during critical stages of development.

Mucosal concentrations of N-acetyl-5-aminosalicylic acid related to endoscopic activity in ulcerative colitis patients with mesalamine

BACKGROUND AND AIM

5-Aminosalicylic acid (5-ASA) is a fundamental treatment for mild-to-moderate ulcerative colitis (UC). 5-ASA is taken up into the colonic mucosa and metabolized to N-acetyl-5-ASA (Ac-5-ASA). Few studies have assessed whether mucosal 5-ASA and Ac-5-ASA concentrations are associated with endoscopic remission. This study aimed to investigate differences in 5-ASA and Ac-5-ASA concentrations according to endoscopic activity.

METHODS

This single-center, prospective, cross-sectional study was conducted between March 2018 and February 2019. UC patients who were administered with 5-ASA medication for at least 8 weeks before sigmoidoscopy were enrolled. Mucosal 5-ASA and Ac-5-ASA concentrations were measured using liquid chromatography with tandem mass spectrometry. The primary endpoint was defined as the difference in mucosal concentrations of 5-ASA and Ac-5-ASA, according to the Mayo endoscopic subscore (MES).

RESULTS

Mucosal concentrations were analyzed in 50 patients. In the sigmoid colon, the median 5-ASA concentration in patients with MES of 0 (17.3 ng/mg) was significantly higher than MES ≥ 1 (6.4 ng/mg) (P = 0.019). The median 5-ASA concentrations in patients with Ulcerative Colitis Endoscopic Index of Severity ≤ 1 (16.4 ng/mg) were also significantly higher than in patients with Ulcerative Colitis Endoscopic Index of Severity ≥ 2 (4.63 ng/mg) (P = 0.047). In the sigmoid colon, the concentration of Ac-5-ASA was higher in patients with MES of 0 (21.2 ng/mg) than in patients with MES ≥ 1 (5.81 ng/mg) (P = 0.022).

CONCLUSIONS

The present study showed that mucosal Ac-5-ASA concentrations, as well as 5-ASA concentrations, are higher in UC patients with endoscopic remission. Ac-5-ASA may be useful for a biomarker of 5-ASA efficacy.

Similar pharmacokinetics of three dosing regimens comprising two oral delayed-release mesalamine formulations in healthy adult volunteers: Randomised, open-label, parallel-group study

Aims

Mesalamine is the first‐line therapy for treating mild‐to‐moderate ulcerative colitis. Multiple mesalamine formulations are available, with similar safety and efficacy profiles. Mesalamine is commonly administered as divided dosing, although once‐daily dosing may provide benefits for patients. We evaluated the pharmacokinetics of three dosing regimens of two oral delayed‐release mesalamine formulations in healthy adult volunteers.

Methods

A randomised, open‐label, parallel‐group study of mesalamine pharmacokinetics following Lialda 2 × 1.2 g once daily (QD) (dose A), Asacol 6 × 400 mg QD (dose B), or Asacol 2 × 400 mg three times daily (TID) (dose C) over 7 days. Assessments included 5‐aminosalicylic acid (5‐ASA) and N‐acetyl 5‐aminosalicylic acid (N‐Ac‐5‐ASA, primary metabolite) pharmacokinetics (A_e(%), AUC_0‐24 and C_max), safety and tolerability.

Results

All enrolled volunteers (n = 37) completed the study. Steady state was achieved for all treatments by day 4. Ratios (95% CI) of means for steady‐state AUC_0‐24 (dose A vs B 90.3% [39.8, 204.8], dose A vs C 123.5% [55.3, 275.7], dose B vs C 136.8% [61.3, 305.5]) and C_max (dose A vs B 106.0% [46.4, 242.2], dose A vs C 133.0% [59.1, 299.0], dose B vs C 125.5% [55.8, 282.1]) were similar for all 5‐ASA treatments. Mean urinary excretion of 5‐ASA plus N‐Ac‐5‐ASA was comparable between treatments (dose A 21.3%, dose B 20.2%, dose C 17.9%). All treatment regimens were well tolerated; no safety issues were observed.

Conclusions

Plasma and urine pharmacokinetics for Asacol TID, Asacol QD, and Lialda QD are similar, suggesting similar daily systemic exposures can be obtained with either TID or QD dosing. NCT00751699.

Colitis and Crohn's Foundation (India) consensus statements on use of 5-aminosalicylic acid in inflammatory bowel disease

Despite several recent advances in therapy in inflammatory bowel disease (IBD), 5-aminosalicylic acid (5-ASA) therapy has retained its place especially in ulcerative colitis. This consensus on 5-ASA is obtained through a modified Delphi process, and includes guiding statements and recommendations based on literature evidence (randomized trials, and observational studies), clinical practice, and expert opinion on use of 5-ASA in IBD by Indian gastroenterologists. The aim is to aid practitioners in selecting appropriate treatment strategies and facilitate optimal use of 5-ASA in patients with IBD.

Involvement of Enteric Glia in Small Intestine Neuromuscular Dysfunction of Toll-Like Receptor 4-Deficient Mice

Enteric glial cells (EGCs) influence nitric oxide (NO)⁻ and adenosine diphosphate (ADP)⁻ mediated signaling in the enteric nervous system (ENS). Since Toll-like receptor 4 (TLR4) participates to EGC homoeostasis, this study aimed to evaluate the possible involvement of EGCs in the alterations of the inhibitory neurotransmission in TLR4^−/− mice. Ileal segments from male TLR4^−/− and wild-type (WT) C57BL/6J mice were incubated with the gliotoxin fluoroacetate (FA). Alterations in ENS morphology and neurochemical coding were investigated by immunohistochemistry whereas neuromuscular responses were determined by recording non-adrenergic non-cholinergic (NANC) relaxations in isometrically suspended isolated ileal preparations. TLR4^−/− ileal segments showed increased iNOS immunoreactivity associated with enhanced NANC relaxation, mediated by iNOS-derived NO and sensitive to P2Y1 inhibition. Treatment with FA diminished iNOS immunoreactivity and partially abolished NO⁻ and ADP⁻ mediated relaxation in the TLR4^−/− mouse ileum, with no changes of P2Y1 and connexin-43 immunofluorescence distribution in the ENS. After FA treatment, S100β and GFAP immunoreactivity in TLR4^−/− myenteric plexus was reduced to levels comparable to those observed in WT. Our findings show the involvement of EGCs in the alterations of ENS architecture and in the increased purinergic and nitrergic-mediated relaxation, determining gut dysmotility in TLR4^−/− mice.

Solving the questions regarding 5-aminosalitylate formulation in the treatment of ulcerative colitis

5-aminosalicylate is a fundamental treatment for patients with ulcerative colitis with mild-to-moderate disease; however, evidence for 5-aminosalicylate treatment is unclear in some situations. This review discusses the clinical guidelines and previous studies, and highlights the following points: (1) Although rectal 5-aminosalicylate is effective for proctitis, physicians should endeavor to reduce patient's distress when administering suppositories or enema as the first-line therapy. It should be clarified whether oral 5-aminosalicylate alone with a drug delivery system that allows higher 5-aminosalicylate concentrations to reach the distal colon would be as effective as rectal 5-aminosalicylate therapy. (2) There has been no direct evidence demonstrating the clinical efficacy of switching the 5-aminosalicylate treatment to other 5-aminosalicylate formulations. However, switching to a different 5-aminosalicylate formulation may be indicated if clinical symptoms are not progressive. (3) Several studies have shown that colonic mucosal 5-aminosalicylate concentration correlates with clinical and endoscopic severity; however, it is unclear whether a high 5-aminosalicylate concentration has therapeutic efficacy. (4) The maximum dose of 5-aminosalicylate is necessary for patients with risk factors for recurrence or hospitalization. (5) Optimization of 5-aminosalicylate dosage may be indicated even for quiescent patients with ulcerative colitis if mucosal healing is not obtained, and if patients have multiple risk factors for recurrence. (6) Furthermore, the discontinuation of 5-aminosalicylate is acceptable when biologics are used. Because there are many "old studies" providing evidence for 5-aminosalicylate formulations, more clinical studies are needed to establish new evidence.

Nanoparticle-Mediated Drug Delivery Systems For The Treatment Of IBD: Current Perspectives

Inflammatory bowel disease (IBD), which mainly consists of Crohn’s disease and ulcerative colitis, is a chronic and relapsing inflammatory condition of the gastrointestinal tract. The traditional treatment strategies relied on frequent administration of high dosages of medications, including antibiotics, non-steroidal anti-inflammatory drugs, biologics, and immunomodulators, with the goal of reducing inflammation. Some of these medications were effective in alleviating the early-stage inflammatory symptoms, but their long-term efficacies were compromised by the accumulation of toxicities. Recently, nanoparticle (NP)-based drugs have been widely studied for their potential to solve such problems. Various mechanisms/strategies, including size-, charge-, pH-, pressure-, degradation-, ligand-receptor-, and microbiome- dependent drug delivery systems, have been exploited in preclinical studies. A certain number of NP delivery systems have sought to target drugs to the inflamed intestine. Although several NP-based drugs have entered clinical trials for the treatment of IBD, most have failed due to premature drug release, weak targeting ability, and the high immune toxicity of some of the synthetic nanomaterials that have been used to fabricate the NPs. Therefore, there is still a need for rationally designed and stable NP drug delivery system that can specifically target drugs to the disease site, prolong the drug’s residence time, and minimize systemic side effects. This review will analyze the current state of the art in NP-mediated drug delivery for IBD treatment. We will focus on topics such as deliverable targets (at the tissue or cellular level) for treating inflammation; the target-homing NP materials that can interact with such targets; and the major administration routes for treating IBD. These discussions will integrate notable trends in the research and development of IBD medications, including multi-responsive NP-mediated delivery and naturally-derived targeting NPs. Finally, current challenges and future directions will be presented in the hopes of advancing the study of NP-mediated strategies for treating IBD.

Mucosal 5-aminosalicylic acid concentration, drug formulation and mucosal microbiome in patients with quiescent ulcerative colitis

BACKGROUND

5-aminosalicylic acid (5-ASA) is the first-line therapy for ulcerative colitis (UC). 5-ASA acts locally in the colonic mucosa by numerous proposed mechanisms, and is metabolised by N-acetyltransferase (NAT). Large variations in mucosal 5-ASA concentrations have been reported, but the underlying mechanisms are not understood.

AIM

To study the relationship between 5-ASA concentration, 5-ASA formulation, NAT genotype and bacterial microbiome in patients with UC.

METHODS

Patients with quiescent UC, using monotherapy of Mezavant (n = 18), Asacol (n = 14) or Pentasa (n = 10), 4.0-4.8 g/day were included. 5-ASA was measured in colonic mucosal biopsies and serum by ultra-high performance liquid chromatography. NAT genotypes were determined by Sanger sequencing. Bacterial microbiome was sequenced from faeces and mucosa by 16S rRNA sequencing using Illumina Miseq.

RESULTS

Mezavant provided the highest mucosal 5-ASA levels (geometric mean 2.39 ng/mg), followed by Asacol (1.60 ng/mg, 33% lower, P = 0.50) and Pentasa (0.57 ng/mg, 76% lower, P = 0.033). Mucosal 5-ASA concentration was not associated with NAT genotype, but serum 5-ASA concentration and NAT1 genotype was associated (P = 0.044). Mucosal 5-ASA concentration was positively associated with mucosal bacterial diversity (P = 0.0005) and bacterial composition. High mucosal 5-ASA concentration was related to reduced abundance of pathogenic bacteria such as Proteobacteria, and increased abundance of several favourable bacteria such as Faecalibacterium.

CONCLUSIONS

Mucosal 5-ASA concentration is positively associated with bacterial diversity and a mucosal bacterial composition that are perceived favourable in UC. Mezavant yielded higher mucosal 5-ASA concentrations than Pentasa. 5-ASA may have beneficial effects on the mucosal microbiome, and high concentrations possibly amend dysbiosis in UC.

Influence of Pharmaceutical Formulation on the Mucosal Concentration of 5-Aminosalicylic Acid and N-Acetylmesalamine in Japanese Patients with Ulcerative Colitis

The efficacy of 5-aminosalicylic acid (5-ASA) as the first-line therapy for ulcerative colitis (UC) is determined by the extent of drug delivery to the inflamed region. Moreover, differences among the various formulations influence delivery of the drug. In this study, we examined the clinical significance of colonic mucosal concentrations of 5-ASA and N-acetylmesalamine (Ac-5-ASA) in UC patients receiving a pH-dependent or time-dependent release formulation of 5-ASA. The subjects were 67 patients with UC who were treated with a pH-dependent or time-dependent formulation of 5-ASA between December 2011 and April 2014. A retrospective observational analysis of clinical outcomes was performed using the clinical activity index (CAI) obtained on the day of biopsy. Colonic mucosal concentrations of 5-ASA and Ac-5-ASA in biopsy samples were measured by LC-tandem mass spectrometry/mass spectrometry. Patients who were treated with the pH-dependent formulation had higher colon mucosal concentrations of 5-ASA than those who were treated with the time-dependent formulation. Additionally, 5-ASA concentration was significantly higher in patients with CAI scores ≤3. A higher concentration of Ac-5-ASA was achieved with the time-dependent formulation than with the pH-dependent formulation. Furthermore, patients with CAI scores ≤3 had higher concentrations of 5-ASA than those with CAI scores ≥4. The colonic mucosal concentration of 5-ASA in patients with UC is influenced by the pharmaceutical formulation and the remission status of UC.

Extracts from Hericium erinaceus relieve inflammatory bowel disease by regulating immunity and gut microbiota

Hericium erinaceus (HE), a traditional edible mushroom, is known as a medicine food homology to ameliorate gastrointestinal diseases. To investigate whether HE is clinically effective in alleviating inflammatory bowel disease (IBD), HE extracts (polysaccharide, alcoholic extracts and whole extracts were prepared using solvent extraction methods) were administrated for 2 weeks in rats with IBD induced by trinitro-benzene-sulfonic acid (TNBS) enema (150 mg/kg). Significant clinical and histological changes in IBD rats were identified, including damage activity, common morphous and tissue damage index scores in colonic mucosa and myeloperoxidase (MPO) activity. The damage activity, common morphous and tissue damage index scores in colonic mucosa (P <0.05) were improved, MPO activities were decreased. Inflammatory factors were also differentially expressed in colonic mucosa in IBD rats, including serum cytokines, Foxp3 and interleukin (IL)-10 were increased while NF-κB p65 and tumor necrosis factor (TNF)-α were decreased (P <0.05), and T cells were activated (P <0.05), especially in the alcohol extracts-treated group. We also found that the structure of gut microbiota of the H. erinaceus extracts-treated groups changed significantly by compared with the model group. Further studies revealed that the polysaccharides in HE extracts may play a prebiotic role, whereas the alcoholic extracts show bactericidin-like and immunomodulatory effects. Taken together, we demonstrated that H. erinaceus extracts could promote the growth of beneficial gut bacteria and improve the host immunity in vivo IBD model, which shows clinical potential in relieving IBD by regulating gut microbiota and immune system.

Pharmacokinetics in Wistar Rats of 5-[(4-Carboxybutanoyl)Amino]-2-Hydroxybenzoic Acid: A Novel Synthetic Derivative of 5-Aminosalicylic Acid (5-ASA) with Possible Anti-Inflammatory Activity

5-[(4-carboxybutanoyl)amino]-2-hydroxybenzoic acid (C2) is a novel synthetic derivative of 5-aminosalicylic acid (5-ASA), which is currently being evaluated ex vivo as an anti-inflammatory agent and has shown satisfactory results. This study aimed to obtain the pharmacokinetic profiles, tissue distribution and plasma protein binding of C2 in Wistar Rats. Additionally, an HPLC method was developed and validated to quantify C2 in rat plasma. The pharmacokinetic profiles of intragastric, intravenous and intraperitoneal administration routes at singles doses of 100, 50, and 100 mg/kg, respectively, were studied in Wistar rats. The elimination half-life of intravenously administered C2 was approximately 33 min. The maximum plasma level of C2 was reached approximately 24 min after intragastric administration, with a Cmax value of 2.5 g/mL and an AUCtot value of 157 μg min-1/mL; the oral bioavailability was approximately 13%. Following a single intragastric or oral dose (100 mg/kg), C2 was distributed and detected in all examined tissues (including the brain and colon). The results showed that C2 accumulates over time. The plasma protein binding results indicated that the unbound fraction of C2 at concentrations of 1 to 20 μg/mL ranged from 89.8% to 92.5%, meaning that this fraction of C2 is available to cross tissues. Finally, the blood-plasma partitioning (BP ratio) of C2 in rat plasma was 0.71 and 0.6 at concentrations of 5 and 10 μg/mL, respectively, which indicates that C2 is free in the plasmatic phase and not inside blood cells. The results of this study suggest that a fraction of the administered C2 dose is absorbed in the stomach, and the fraction that is not absorbed reaches the small intestine and colon. This distribution constitutes the main advantage of C2 compared with 5-ASA for the treatment of ulcerative colitis (UC) and Crohn's disease (CD).

Efficacy of a pH-dependent controlled-release mesalazine based on clinical and endoscopic assessment for ulcerative colitis: a retrospective cohort study

Background

We conducted a retrospective cohort study to clinically and endoscopically assess the efficacy of delayed-release mesalazine for ulcerative colitis.

Methods

The study included 104 ulcerative colitis patients (52 men, 52 women) initiated on treatment with delayed-release mesalazine between 2009 and 2012. The clinical symptoms at months 0, 1, and 12 were scored using the clinical activity index. An endoscopic index was also used to determine disease activity in 72 patients who underwent total colonoscopy before and after mesalazine treatment.

Results

The clinical activity index at months 0, 1, and 12 were 4.6±2.8, 3.4±1.8, and 2.8±1.4, respectively, decreasing with time after the start of mesalazine treatment (P<0.001). The endoscopic index decreased significantly from 4.5±3.2 before to 3.1±2.8 after the start of delayed-release mesalazine treatment in the mean follow-up period of 1.0±0.4 years (P<0.001).

Conclusion

Delayed-release mesalazine was confirmed to be effective both clinically and endoscopically.

Release of 5-Aminosalicylic Acid (5-ASA) from Mesalamine Formulations at Various pH Levels

Introduction

Oral formulations of 5-aminosalicylic acid (5-ASA) for treatment of ulcerative colitis have been developed to minimize absorption prior to the drug reaching the colon. In this study, we investigate the release of 5-ASA from available oral mesalamine formulations in physiologically relevant pH conditions.

Methods

Release of 5-ASA from 6 mesalamine formulations (APRISO^®, Salix Pharmaceuticals, Inc., USA; ASACOL^® MR, Procter & Gamble Pharmaceuticals UK Ltd.; ASACOL^® HD, Procter & Gamble Pharmaceuticals, USA; MEZAVANT XL^®, Shire US Inc.; PENTASA^®, Ferring Pharmaceuticals, Ltd., UK; SALOFALK^®, Dr. Falk Pharma UK Ltd.) was evaluated using United States Pharmacopeia apparatus I and II at pH values of 1.0 (2 h), 6.0 (1 h), and 6.8 (8 h). Dissolution profiles were determined for each formulation, respectively.

Results

Of the tested formulations, only the PENTASA formulation demonstrated release of 5-ASA at pH 1.0 (48%), with 56% cumulative release after exposure to pH 6.0 and 92% 5-ASA release after 6–8 h at pH 6.8. No other mesalamine formulation showed >1% drug release at pH 1.0. The APRISO formulation revealed 36% 5-ASA release at pH 6.0, with 100% release after 3 h at pH 6.8. The SALOFALK formulation revealed 11% 5-ASA release at pH 6.0, with 100% release after 1 h at pH 6.8. No 5-ASA was released by the ASACOL MR, ASACOL HD, and MEZAVANT XL formulations at pH 6.0. At pH 6.8, the ASACOL MR and ASACOL HD formulations exhibited complete release of 5-ASA after 4 and 2 h, respectively, and the MEZAVANT XL formulation demonstrated complete 5-ASA release over 6–7 h.

Conclusion

5-Aminosalicylic acid release profiles were variable among various commercially available formulations.

Funding

Shire Development LLC.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0206-4) contains supplementary material, which is available to authorized users.

Accuracy of Rapid Fecal Calprotectin Test in Monitoring Inflammatory Bowel Diseases Under Treatment with TNFα Antagonists

BACKGROUND

Anti-TNFα antibodies are effective in treating inflammatory bowel diseases (IBDs) unresponsive to the standard treatments. Information about the role of rapid fecal calprotectin (FC) in monitoring ambulatory IBD patients under treatment with anti-TNFα is lacking. Our aim was to assess the accuracy of rapid FC in monitoring those patients.

METHODS

Seventy-two patients (38 males, 34 females, mean age 42.5 years, range 23-57 years), affected by ulcerative colitis (UC) (20 patients) or by Crohn's disease (CD) (52 patients) were treated with anti-TNFα antibodies. FC was assessed by a rapid semiquantitative test.

RESULTS

With respect to the absence of clinical remission, FC test showed sensitivity of 71.8 %, specificity of 65.2 %, PPV of 41.8 %, and NPV of 86.9 %. In UC patients, FC test showed a sensitivity of 66.7 %, a specificity of 56.1 %, a PPV of 18.2 %, and a NPV of 92.0 %. In CD patients, FC test showed sensitivity of 70.6 %, specificity of 65.2 %, PPV of 50.0 %, and NPV of 81.8 %. With respect to the presence of endoscopic lesions, FC test showed sensitivity of 73.5 %, specificity of 96.0 %, PPV of 96.2 %, and NPV of 72.7 %. In UC patients, FC test showed sensitivity of 47.2 %, specificity of 84.6 %, PPV of 89.5 %, and NPV of 36.7 %. In CD patients, FC test showed sensitivity of 90.1 %, specificity of 79.7 %, PPV of 71.9 %, and NPV of 93.3 %.

CONCLUSIONS

Diagnostic accuracy of rapid FC seems better in predicting persistence of endoscopic lesions than clinical remission in IBD patients under treatment with anti-TNFα.