Review article: alginate-raft formulations in the treatment of heartburn and acid reflux

Simultaneous Delivery of Curcumin and Resveratrol via In Situ Gelling, Raft-Forming, Gastroretentive Formulations

Curcumin and resveratrol are polyphenolic compounds that have been shown to exhibit synergistic therapeutic properties including anti-inflammatory, anticancer, and antiulcer activities, which may be exploited for the treatment of gastric diseases. However, both compounds have poor aqueous solubility and rapid metabolism, resulting in a low oral bioavailability. In situ gelling, liquid formulations were developed to produce a gastroretentive, raft-forming delivery vehicle to improve bioavailability. Solid dispersions containing a mixture of curcumin and resveratrol with Eudragit® EPO (Cur/Res-SD) were first prepared using solvent evaporation, to improve the solubility and dissolution of the compounds. Solid dispersions of a weight ratio of 1:10 curcumin/resveratrol to Eudragit® EPO were subsequently incorporated into in situ gelling, liquid formulations based on the gelling polymers, sodium alginate (low viscosity and medium viscosity), pectin, and gellan gum, respectively. Calcium carbonate and sodium bicarbonate were included to produce carbon dioxide bubbles in the gel matrix, on exposure to gastric fluid, and to achieve flotation. Moreover, the calcium ions acted as a crosslinking agent for the hydrogels. Optimized formulations floated rapidly (<60 s) in simulated gastric fluid (pH = 1.2) and remained buoyant, resulting in the gradual release of more than 80% of the curcumin and resveratrol content within 8 h. The optimized formulation based on medium-viscosity sodium alginate exhibited enhanced cytotoxic activity toward human gastric adenocarcinoma cell lines (AGS), compared with unformulated curcumin and resveratrol compounds, and increased anti-inflammatory activity against RAW 264.7 macrophage cells compared with the NSAID, indomethacin. These findings demonstrate that in situ gelling, liquid formulations, loaded with a combination of curcumin and resveratrol in the form of solid dispersions, show potential as gastroretentive delivery systems for local and systemic effects.

The consensus of the Asociación Mexicana de Gastroenterología on the diagnosis and treatment of gastroesophageal reflux and gastroesophageal reflux disease in infants

Gastroesophageal reflux (GER) is a frequent normal phenomenon in children of any age. It is more common in infants, in whom the majority of episodes are short-lived and cause no other symptoms or complications, differentiating it from gastroesophageal reflux disease (GERD). The diagnosis and management of GER and GERD continue to be a challenge for the physician. Therefore, the aim of the Asociación Mexicana de Gastroenterología was to adapt international documents to facilitate their adoption by primary care physicians, with the goal of standardizing quality of care and reducing the number of diagnostic tests performed and inappropriate medication use. The ADAPTE methodology was followed, and the recommendations were approved utilizing the Delphi strategy. The executive committee carried out the review of the guidelines, position papers, and international reviews that met the a priori quality criteria and possible applicability in a local context. The recommendations were taken from those sources and adapted, after which they were approved by the working group. The consensus consists of 25 statements and their supporting information on the diagnosis and treatment of GER and GERD in infants. The adapted document is the first systematic effort to provide an adequate consensus for use in Mexico, proposing a practical approach to and management of GER and GERD for healthcare providers.

A rapid-floating natural polysaccharide gel-raft with double-effect for the treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a prevalent gastrointestinal condition characterized by regurgitating stomach contents into the esophagus, causing mucosal damage or erosion. Clinical physical protection treatment mainly relies on the use of floating rafts. Bletilla striata (BS) is widely regarded as the first-choice drug for treating digestive tract injuries in Chinese Medicine. The rapid-floating gel-raft (B-R) was prepared via a one-step swelling method using natural BS polysaccharide and glyceryl monooleate. Panax notoginseng saponins (PNS) were loaded to further prepare P/B-R according to clinical experience. Possessing hydrophobic dense, stratified porous structure and stable rheological properties, an outperforming floating performance of P/B-R was proven compared with Gaviscon® (alginate-antacid formulation) in vitro. In vivo imaging results showed that P/B-R can retain and adhere to the gastric mucosa of rats for up to 90 min, protecting and repairing the mucosa. Besides physical protection in situ, the systemic effects of antioxidant and anti-inflammatory actions for treating GERD were achieved through the intestinal release of PNS. Acid-labile PNS was protected by P/B-R against gastric acid, attaining the desired release and permeability. A significantly effective mucosa injury protective effect of P/B-R was found in ethanol-induced gastric damage model on rats. Moreover, P/B-R exhibits excellent biosafety at the cellular level.

Characterization of novel alginate-Aloe Vera raft systems for treatment of gastroesophageal reflux disease

Raft-forming systems are designed to relieve reflux symptoms by forming a physical barrier on top of the stomach. The present study aimed to evaluate the physico-chemical properties of alginate-aloe vera raft-forming systems for the first time. To achieve this goal, aloe vera was used in the proportion of 1 and 1.5 % in raft suspensions containing 5 % alginate as the main component of gel structure. Rafts were characterized by their volume, floating behavior, thickness, swelling properties, strength, resilience, reflux resistance, and acid neutralization capacity (ANC). Results showed the effectiveness of aloe vera in forming rafts that were voluminous, buoyant with greater total floating time (TFT), and stronger than formulations with no aloe vera. Furthermore, data showed that the presence of aloe vera could improve resilience time, swelling proportions, resistance to reflux under simulant conditions of movement in the stomach, and ANC values of rafts. Rafts were further characterized by oscillatory strain sweep test, differential scanning calorimetry, and Fourier transform infrared spectroscopy. Evaluation of the mechanical properties of rafts displayed a viscoelastic behavior of gels corresponding to the internal cross-linked structure of rafts. This study demonstrated that designing of alginate-aloe vera rafts can be suitable for the treatment of gastro-esophageal reflux disorders.

Pharmacological treatment of gastro-oesophageal reflux in children

BACKGROUND

Gastro-oesophageal reflux (GOR) is characterised by the regurgitation of gastric contents into the oesophagus. GOR is a common presentation in infancy, both in primary and secondary care, affecting approximately 50% of infants under three months old. The natural history of GOR in infancy is generally of a self-limiting condition that improves with age, but older children and children with co-existing medical conditions can have more protracted symptoms. The distinction between gastro-oesophageal reflux disease (GORD) and GOR is debated. Current National Institute of Health and Care Excellence (NICE) guidelines define GORD as GOR causing symptoms severe enough to merit treatment. This is an update of a review first published in 2014.

OBJECTIVES

To assess the effects of pharmacological treatments for GOR in infants and children.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE, Embase, and Web of Science up to 17 September 2022. We also searched for ongoing trials in clinical trials registries, contacted experts in the field, and searched the reference lists of trials and reviews for any additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any currently-available pharmacological treatment for GOR in children with placebo or another medication. We excluded studies assessing dietary management of GORD and studies of thickened feeds. We included studies in infants and children up to 16 years old.

DATA COLLECTION AND ANALYSIS

We used standard methodology expected by Cochrane.

MAIN RESULTS

We included 36 RCTs involving 2251 children and infants. We were able to extract summary data from 14 RCTs; the remaining trials had insufficient data for extraction. We were unable to pool results in a meta-analysis due to methodological differences in the included studies (including heterogeneous outcomes, study populations, and study design). We present the results in two groups by age: infants up to 12 months old, and children aged 12 months to 16 years old. Infants Omeprazole versus placebo: there is no clear effect on symptoms from omeprazole. One study (30 infants; very low-certainty evidence) showed cry/fuss time in infants aged three to 12 months had altered from 246 ± 105 minutes/day at baseline (mean +/- standard deviation (SD)) to 191 ± 120 minutes/day in the omeprazole group and from 287 ± 132 minutes/day to 201 ± 100 minutes/day in the placebo group (mean difference (MD) 10 minutes/day lower (95% confidence interval (CI) -89.1 to 69.1)). The reflux index changed in the omeprazole group from 9.9 ± 5.8% in 24 hours to 1.0 ± 1.3% and in the placebo group from 7.2 ± 6.0% to 5.3 ± 4.9% in 24 hours (MD 7% lower, 95% CI -4.7 to -9.3). Omeprazole versus ranitidine: one study (76 infants; very low-certainty evidence) showed omeprazole may or may not provide symptomatic benefit equivalent to ranitidine. Symptom scores in the omeprazole group changed from 51.9 ± 5.4 to 2.4 ± 1.2, and in the ranitidine group from 47 ± 5.6 to 2.5 ± 0.6 after two weeks: MD -4.97 (95% CI -7.33 to -2.61). Esomeprazole versus placebo: esomeprazole appeared to show no additional reduction in the number of GORD symptoms compared to placebo (1 study, 52 neonates; very low-certainty evidence): both the esomeprazole group (184.7 ± 78.5 to 156.7 ± 75.1) and placebo group (183.1 ± 77.5 to 158.3 ± 75.9) improved: MD -3.2 (95% CI -4.6 to -1.8). Children Proton pump inhibitors (PPIs) at different doses may provide little to no symptomatic and endoscopic benefit. Rabeprazole given at different doses (0.5 mg/kg and 1 mg/kg) may provide similar symptom improvement (127 children in total; very low-certainty evidence). In the lower-dose group (0.5 mg/kg), symptom scores improved in both a low-weight group of children (< 15 kg) (mean -10.6 ± SD 11.13) and a high-weight group of children (> 15 kg) (mean -13.6 ± 13.1). In the higher-dose groups (1 mg/kg), scores improved in the low-weight (-9 ± 11.2) and higher-weight groups (-8.3 ± 9.2). For the higher-weight group, symptom score mean difference between the two different dosing regimens was 2.3 (95% CI -2 to 6.6), and for the lower-weight group, symptom score MD was 4.6 (95% CI -2.9 to 12). Pantoprazole: pantoprazole may or may not improve symptom scores at 0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg pantoprazole in children aged one to five years by week eight, with no difference between 0.3 mg/kg and 1.2 mg/kg dosing (0.3 mg/kg mean -2.4 ± 1.7; 1.2 mg/kg -1.7 ± 1.2: MD 0.7 (95% CI -0.4 to 1.8)) (one study, 60 children; very low-certainty evidence). There were insufficient summary data to assess other medications.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence about symptom improvements and changes in pH indices for infants. There are no summary data for endoscopic changes. Medications may or may not provide a benefit (based on very low-certainty evidence) for infants whose symptoms remain bothersome, despite nonmedical interventions or parental reassurance. If a medication is required, there is no clear evidence based on summary data for omeprazole, esomeprazole (in neonates), H₂antagonists, and alginates for symptom improvements (very low-certainty evidence). Further studies with longer follow-up are needed. In older children with GORD, in studies with summary data extracted, there is very low-certainty evidence that PPIs (rabeprazole and pantoprazole) may or may not improve GORD outcomes. No robust data exist for other medications. Further RCT evidence is required in all areas, including subgroups (preterm babies and children with neurodisabilities).

Arctic Edible Brown Alga Fucus distichus L.: Biochemical Composition, Antiradical Potential and Human Health Risk

Fucus distichus L. is the dominant canopy-forming macroalga in the rocky intertidal areas of the Arctic and Subarctic. In the present study, the impact of the geographic location of F. distichus collected in the Baffin Sea (BfS), Norwegian Sea (NS), White Sea (WS), and Barents Sea (BS) on the variations in biochemical composition, antiradical properties, and health risk was evaluated. The accumulation of main carbohydrates (fucoidan, mannitol, and alginic acid) varied from 335 mg/g dry weight (DW) in NS to 445 mg/g DW in BS. The highest level of the sum of polyphenols and flavonoids was found in samples of F. distichus from WS and was located in the following ranking order: BS < BfS < NS < WS. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of seaweed is correlated with its phenolic content. It is notable that in most Arctic F. distichus samples, Cd, Cr, Pb, and Ni were not detected or their concentrations were below the limit of quantification. According to calculated targeted hazard quotient and hazard index values, all studied samples of Arctic F. distichus are safe for daily consumption as they do not pose a carcinogenic risk to the health of adults or children. The results of this study support the rationale for using Arctic F. distichus as a rich source of polysaccharides, polyphenols, and flavonoids with important antiradical activity. We believe that our data will help to effectively use the potential of F. distichus and expand the use of this algae as a promising and safe raw material for the food and pharmaceutical industries.

Optimizing the treatment of patients with gastroesophageal reflux disease: focus on nutritional risk factors and nutritional approaches

Gastroesophageal reflux disease (GERD) is a common upper gastrointestinal disease characterized by occurrence of typical symptoms associated with an increase in esophageal acid exposure. The transient lower esophageal sphincter relaxations (TLESRs) and hypotension is the key pathophysiological mechanisms of the development of reflux disease. For a long time, it was assumed that certain nutritional and lifestyle factors affect the mechanisms of the onset and progress of GERD. However, the accumulated scientific findings show contradicting results regarding contribution of these factors to the development of reflux disease. The treatment of GERD requires lifestyle modifications, diet therapy, pharmacotherapy, and, if necessary, surgery. Proton pump inhibitors (PPIs) form the basis of pharmacotherapy. Lifestyle modifications, including dietary therapy, is also part of the treatment plan for patients with reflux symptoms, however no clear guidelines in this regard are determined due to the lack of good evidence base. Yet, while the problems associated with the long-term use of PPIs are explored, patients and physicians are increasingly interested in the role of diet in the treatment of GERD. The article provides an overview of the dietary aspects in GERD with a focus on nutritional components and their impact on the pathophysiology and treatment of this disease. Although sequential food-group elimination in GERD is common in clinical practice, literature data demonstrate a broader approach, including reduction of sugar intake, increase of dietary fibres in the diet, and changes in patterns of eating habits as a general principle.

Topical Alginate Protection against Pepsin-Mediated Esophageal Damage: E-Cadherin Proteolysis and Matrix Metalloproteinase Induction

Epithelial barrier dysfunction is a hallmark of gastroesophageal reflux disease (GERD) related to symptom origination, inflammatory remodeling and carcinogenesis. Alginate-based antireflux medications were previously shown to topically protect against peptic barrier disruption, yet the molecular mechanisms of injury and protection were unclear. Herein, Barrett's esophageal (BAR-T) cells were pretreated with buffered saline (HBSS; control), dilute alginate medications (Gaviscon Advance or Gaviscon Double Action, Reckitt Benckiser), a viscosity-matched placebo, or ADAM10 and matrix metalloproteinase (MMP) inhibitors before exposure to HBSS pH7.4 or pH4 ± 1 mg/mL pepsin for 10-60 min. Cell viability was assessed by ATP assay; mediators of epithelial integrity, E-cadherin, ADAM10, and MMPs were examined by Western blot and qPCR. Alginate rescued peptic reduction of cell viability (p < 0.0001). Pepsin-pH4 yielded E-cadherin fragments indicative of regulated intramembrane proteolysis (RIP) which was not rescued by inhibitors of known E-cadherin sheddases. Transcriptional targets of E-cadherin RIP fragments were elevated at 24 h (MMP-1,2,9,14; p < 0.01). Alginate rescued E-cadherin cleavage, ADAM10 maturation, and MMP induction (p < 0.01). Results support RIP as a novel mechanism of peptic injury during GERD. Alginate residue after wash-out to mimic physiologic esophageal clearance conferred lasting protection against pepsin-induced molecular mechanisms that may exacerbate GERD severity and promote carcinogenesis in the context of weakly acidic reflux.

The development of an in-situ biopolymer-based floating gel for the oral delivery of metformin hydrochloride

Diabetes remains a global public health threat because of its increasing prevalence and mortality, especially in people under the age of 25. Metformin hydrochloride (HCl), as recommended by American Diabetes Association in 2022, is the first-line therapy for type 2 diabetes in adults. Metformin has low oral bioavailability due to poor permeability. Therefore, by developing metformin HCl oral in situ gel, sustained delivery of metformin can be achieved, thus enhancing the absorption of the drug. Sodium alginate and pectin were used for formulating the system. Different adjuvant polymers, including HPMC K4M, HPMC K100 LV, PEG 4000, and SCMC were used as released-pattern-modifying agents. All formulations could afloat in 0.1 N HCl at the pH of 1.2 within a minute and stay afloat for over 8 h. The optimized formulation could be made from either sodium alginate (2%) and HPMC K4M (0.5%) or pectin (2%) and HPMC K4M (2%). The optimized formulations gradually released metformin HCl with a cumulative release of 80% within 8 h. We successfully developed floating in situ gels that can release metformin HCl sustainedly.

Comparison of acid-lowering drugs for endoscopy negative reflux disease: Systematic review and network Meta-Analysis

BACKGROUND

The comparative efficacy and safety of medical therapies for gastro-esophageal reflux symptoms in endoscopy-negative reflux disease is unclear. We conducted a network meta-analysis to evaluate efficacy and safety of proton pump inhibitors (PPIs), histamine-2-receptor antagonists, potassium-competitive acid blockers (PCABs), and alginates in patients with endoscopy-negative reflux disease.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials from inception to February 1, 2022. We included randomized controlled trials (RCTs) comparing efficacy of all drugs versus each other, or versus a placebo, in adults with endoscopy-negative reflux disease. Results were reported as pooled relative risks with 95% confidence intervals to summarize effect of each comparison tested, with treatments ranked according to P-score.

KEY RESULTS

We identified 23 RCTs containing 10,735 subjects with endoscopy-negative reflux disease. Based on failure to achieve complete relief of symptoms between ≥2 and <4 weeks, omeprazole 20 mg o.d. (P-score 0.94) ranked first, with esomeprazole 20 mg o.d. or 40 mg o.d. ranked second and third. In achieving adequate relief, only rabeprazole 10 mg o.d. was significantly more efficacious than placebo. For failure to achieve complete relief at ≥4 weeks, dexlansoprazole 30 mg o.d. (P-score 0.95) ranked first, with 30 ml alginate q.i.d. combined with omeprazole 20 mg o.d., and 30 ml alginate t.i.d. second and third. In terms of failure to achieve adequate relief at ≥4 weeks, dexlansoprazole 60 mg o.d. ranked first (P-score 0.90), with dexlansoprazole 30 mg o.d. and rabeprazole 20 mg o.d. second and third. All drugs were safe and well-tolerated.

CONCLUSIONS & INFERENCES

Our results confirm superiority of PPIs compared with most other drugs in treating endoscopy-negative reflux disease. Future RCTs should aim to better classify patients with endoscopy-negative reflux disease, and to establish the role of alginates and PCABs in achieving symptom relief in both the short- and long-term.

EsReflux Protocol: Epidemiological Study of Heartburn and Reflux-like Symptoms in Spanish Community Pharmacies

(1) Background: Heartburn and reflux discomfort are frequent reasons for consultation at the community pharmacy. To facilitate the assistance work of the community pharmacist and its coordination between different levels of care, a group of experts in Community Pharmacy, Primary Care, and Gastroenterology have recently worked on an algorithm to manage these symptoms in the community pharmacy (Professional Pharmaceutical Service). The objective of this study is to analyze the clinical and sociodemographic characteristics of patients with heartburn and/or reflux-like symptoms who go to a community pharmacy, and to evaluate the clinical and humanistic results after the implementation of a Professional Pharmaceutical Service. (2) Methods: A pre-post study will be carried out to evaluate clinical and humanistic results after the implementation of a Professional Pharmaceutical Service. We will include 1200 patients who ask for advice or get a non-prescription medication due to acid and/or reflux symptoms in 240 Spanish pharmacies. Clinical data will be collected at baseline and 15 days after the pharmaceutical intervention. The GERD Impact Scale (GIS) questionnaire will be applied to assess changes in heartburn/reflux-like symptoms and quality of life after the intervention.

Gastroesophageal reflux disease: risk factors, current possibilities of diagnosis and treatment optimisation

Gastroesophageal reflux disease (GERD) is one of the most common causes of health care seeking at the primary care level in many countries. At an epidemiological level, GERD has been shown to be associated with a number of risk factors: obesity, tobacco smoking, alcohol abuse, certain patterns of eating behaviour, and the use of several medications. GERD is now regarded as a heterogeneous disease and includes different phenotypes (erosive reflux disease, non-erosive reflux disease, hypersensitive oesophagus, functional heartburn), the proper diagnosis of which improves the effectiveness of therapy in patients with heartburn symptoms. Daily impedance–pH monitoring is known to be an integral part of the diagnostic algorithm for GERD and is a functional diagnostic method to record all types of refluxes entering the oesophagus regardless of pH, to assess their association with symptoms, and to determine whether patients with heartburn symptoms belong to a particular phenotype. Esophageal manometry plays a key role in the evaluation of patients with heartburn symptoms, as it helps to rule out other conditions that may mimic GERD: achalasia cardia and scleroderma esophagus. This technique is used to assess thoracic esophageal motility and sphincter function and in the assessment of patients prior to antireflux surgery or in the refractory course of GERD. The article describes in detail GERD risk factors (triggers of heartburn), as well as diagnostic aspects, taking into account a differentiated approach to patients with heartburn based on daily impedance–pH monitoring data in accordance with the current guidelines and recommendations.

Antacids revisited: review on contemporary facts and relevance for self-management

Heartburn and acid regurgitation are the typical symptoms of gastroesophageal reflux. Despite the availability of several treatment options, antacids remain the mainstay treatment for gastroesophageal reflux-related symptoms based on their efficacy, safety, and over-the-counter availability. Antacids are generally recommended for adults and children at least 12 years old, and the FDA recommends antacids as the first-line treatment for heartburn in pregnancy. This narrative review summarizes the mechanism, features, and limitations related to different antacid ingredients and techniques available to study the acid neutralization and buffering capacity of antacid formulations. Using supporting clinical evidence for different antacid ingredients, it also discusses the importance of antacids as OTC medicines and first-line therapies for heartburn, particularly in the era of the COVID-19 pandemic, in which reliance on self-care has increased. The review will also assist pharmacists and other healthcare professionals in helping individuals with heartburn to make informed self-care decisions and educating them to ensure that antacids are used in an optimal, safe, and effective manner.

The views of African and Middle Eastern Gastroenterologists on the management of mild-to-moderate, non-erosive gastro-esophageal reflux disease (GERD)

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a common gastrointestinal disorder that occurs when backflow of the gastric contents into the esophagus results in troublesome symptoms. Though GERD has been extensively studied in Western populations, literature on the management of GERD in patients in Africa and Middle East (AME) is scarce.

AREAS COVERED

In this review, we provide an overview of the management of mild-to-moderate GERD in AME. Here we focus on the efficacy and safety of currently available treatments for GERD to help physicians and community pharmacists appropriately manage patients with mild-to-moderate GERD in the primary healthcare setting, detailing specific situations and patient scenarios that are relevant to the region, including management of GERD during Ramadan and post-bariatric surgery.

EXPERT OPINION

Under-appreciation of the burden of GERD in the region has resulted in a lack of consensus on management. Barriers that currently prevent the adoption of treatment guidelines in the primary healthcare setting may include lack of availability of local guidelines and referral systems, a paucity of region-specific research, and dogmatic adherence to traditional practice. By increasing awareness, strengthening knowledge, and by more effective utilization of resources, physicians and pharmacists could optimize GERD management strategies to better support patients.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.

Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

The Usages and Potential Uses of Alginate for Healthcare Applications

Due to their unique properties, alginate-based biomaterials have been extensively used to treat different diseases, and in the regeneration of diverse organs. A lot of research has been done by the different scientific community to develop biofilms for fulfilling the need for sustainable human health. The aim of this review is to hit upon a hydrogel enhancing the scope of utilization in biomedical applications. The presence of active sites in alginate hydrogels can be manipulated for managing various non-communicable diseases by encapsulating, with the bioactive component as a potential site for chemicals in developing drugs, or for delivering macromolecule nutrients. Gels are accepted for cell implantation in tissue regeneration, as they can transfer cells to the intended site. Thus, this review will accelerate advanced research avenues in tissue engineering and the potential of alginate biofilms in the healthcare sector.

Opening the Egg Box: NMR spectroscopic analysis of the interactions between s-block cations and kelp monosaccharides

The best-known theory accounting for metal-alginate complexation is the so-called "Egg Box" model. In order to gain greater insight into the metal-saccharide interactions that underpin this model, the coordination chemistry of the corresponding monomeric units of alginate, L-guluronate (GulA) and D-mannuronate (ManA) have been studied herein. GulA and ManA were exposed to solutions of different s-block cations and then analysed by ¹H and ¹³C NMR spectroscopy. It was found that the α/β ratio of the pyranose anomeric equilibria of GulA showed large pertubations from the starting value (α/β = 0.21 ± 0.01) upon contact with 1.0 M Ca²⁺, Sr²⁺, and Ba²⁺ (α/β = 1.50 ± 0.03, 1.20 ± 0.02, and 0.58 ± 0.02, respectively) at pD 7.9, but remained almost constant in the presence of Na⁺, K⁺, and Mg²⁺ (α/β = 0.24 ± 0.01, 0.19 ± 0.01, and 0.26 ± 0.01, respectively). By comparison, no significant changes were observed in the α/β ratios of ManA and related mono-uronates D-glucuronate (GlcA) and D-galacturonate (GalA) in the presence of all of the metal ions surveyed. Analysis of the ¹H and ¹³C coordination chemical shift patterns indicate that the affinity of α-GulA for larger divalent cations is a consequence of the unique ax-eq-ax arrangement of hydroxyl groups found for this uronate anomer.

Characterization of raft-forming alginate suspensions formed in HCl or model food systems at varying pH levels to better simulate gastric postprandial conditions

OBJECTIVE

Elucidate properties of raft-forming alginates in vitro with varying composition, a system in which the raft was formed (HCl solution; tomato soup; protein-rich beverage), and pH levels for a more accurate representation of postprandial gastric conditions.

SIGNIFICANCE

Knowledge of the impact of the food system and pH on properties of raft-forming alginates may aid in formulation optimization. Recommendations may be made on food that is consumed prior to their consumption to optimize efficacy as a therapeutic agent.

METHODS

Dispersions of sodium alginate, calcium carbonate, and sodium bicarbonate were prepared with levels similar to commercial formulations. Rafts were formed in HCl solution, tomato soup, and a protein-rich beverage at pH 1-4 to assess raft properties.

RESULTS

Significant differences (p < 0.05) in raft mass, strength, resilience, and ability to buffer acid were observed depending on the system in which the rafts were formed. The highest mass was obtained in tomato soup (48.5 ± 9.8 g) compared to the protein-rich beverage and HCl solution (32.5 ± 4.5 g and 23.4 ± 4.8 g, respectively) at pH 1. Rafts formed in the protein-rich beverage exhibited the highest strength. Rafts formed in both food systems had a greater ability to buffer added acid compared to rafts formed in HCl solution.

CONCLUSIONS

In vitro testing of raft forming alginates in HCl solution at low pH may not be sufficient to describe in vivo events, as a strong matrix effect was observed when rafts were formed in model meal systems at representative postprandial pH levels.

Optimization and Development of Albumin-Biopolymer Bioconjugates with Solubility-Improving Properties

Bioconjugation is an emerging field in the food and pharmaceutical industry. Due to its biocompatibility and high ligand binding capacity, albumin is widely used in modern drug delivery systems. However, the protein is sensitive to environmental stresses; albumin conjugates, on the other hand, have improved functional properties. Biopolymers are gaining interest due to their biodegradability and safety, compared to synthetic polymers. In this study, albumin–biopolymer bioconjugates were prepared by nonenzymatic Maillard reaction at 60 °C and 80% relative humidity. This nonenzymatic conjugation takes place between reducing sugars and available amino groups of a protein in certain conditions. The optimal molar ratio and time for the conjugation were studied by several investigation methods, including circular dichroism and fluorescence spectroscopy, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), and determination of available amino groups with ortho-phthaldialdehyde (OPA) assay. All of the measurements provided evidence for the covalent bonding of albumin and biopolymers, resulting in bioconjugates. Based on the results, a higher molar ratio and longer time are necessary to complete the reaction with the available amino groups. However, the optimal parameters are specific to each given biopolymer. The rheological behavior of the conjugates is characteristic of the initial biopolymer, which can be useful in drug development. Moreover, both the physical characteristics of albumin and the solubility-improving capacity were enhanced. Therefore, the potential use of albumin–biopolymer bioconjugates in the pharmaceutical industry could be considered.

Maintaining manganese in tumor to activate cGAS-STING pathway evokes a robust abscopal anti-tumor effect

Radiotherapy (RT)-induced DNA damage leaked into cytosol can elicit host antitumor immune response. However, such response rate is unpromising due to limited cyclic GMP-AMP synthase (cGAS) recognition of cytosolic DNA, which could be digested inherently by host DNases. Here we show that synchronizing Mn²⁺ delivery with accumulated cytosolic DNA after RT can promote the activation of cGAS-STING pathway, thereby enhancing RT-induced antitumor immunity. Intratumoral Mn²⁺ injection immediately after RT cannot enhance RT, while intratumoral Mn²⁺ injection 24 h after RT can. Direct-injected Mn²⁺ can be metabolized out from tumor in minutes while RT-induced DNA damage need cells mitotic progression for up to 24 h to accumulate into cytosol. Alginate can maintain Mn²⁺ in tumor for up to 24 h due to it can chelate divalent cations. When the release profile of Mn²⁺ is controlled by alginate (Alg) and synchronized with the accumulation of RT-induced DNA damage, over 90% inhibition rate can be obtained even in the unirradiated tumor, and survival time is significantly extended. This synchronizing strategy provides a simple and novel approach to effectively activate cGAS-STING pathway in tumor and promote RT-induced immunity.

Safety considerations when managing gastro-esophageal reflux disease in infants

Introduction: Gastro-esophageal reflux disease (GERD) in infants is worldwide diagnosed with increasing frequency, resulting in an increasing number of infants exposed to treatment. In this review, we focus on the safety of therapeutic options. Areas covered: English articles were searched from 1990 until May 2020 in PubMed and Google Scholar. Evidence suggests that non-pharmacological treatment is often effective and safe. Guidelines restrict pharmacological treatment to acid-suppressive medication, which is associated with adverse effects, often related to gastro-intestinal dysbiosis and consequences of the latter. Aluminum-free alginates have some efficacy and are not associated with relevant adverse effects. Especially in infants, GERD is often nonacid related. Prokinetics are not recommended because of lack of efficacy and numerous adverse effects. Expert opinion: Pediatric trials are underpowered regarding adverse effects. The number of infants exposed to anti-secretory agents is increasing worldwide, often without indication. Informing healthcare providers about adverse effects of acid-secretory medication may contribute to a more rational use. Acid inhibiting agents such as alginates are a drug class associated with limited efficacy and devoid of serious adverse effects. Regarding prokinetics, the risk of adverse effects outweighs the benefit. Reassurance of parents and nutritional management of GERD in infants is effective and safe.

Advances in the diagnosis and management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a multifaceted disorder encompassing a family of syndromes attributable to, or exacerbated by, gastroesophageal reflux that impart morbidity, mainly through troublesome symptoms. Major GERD phenotypes are non-erosive reflux disease, GERD hypersensitivity, low or high grade esophagitis, Barrett's esophagus, reflux chest pain, laryngopharyngeal reflux, and regurgitation dominant reflux. GERD is common throughout the world, and its epidemiology is linked to the Western lifestyle, obesity, and the demise of Helicobacter pylori. Because of its prevalence and chronicity, GERD is a substantial economic burden measured in physician visits, diagnostics, cancer surveillance protocols, and therapeutics. An individual with typical symptoms has a fivefold risk of developing esophageal adenocarcinoma, but mortality from GERD is otherwise rare. The principles of management are to provide symptomatic relief and to minimize potential health risks through some combination of lifestyle modifications, diagnostic testing, pharmaceuticals (mainly to suppress or counteract gastric acid secretion), and surgery. However, it is usually a chronic recurring condition and management needs to be personalized to each case. While escalating proton pump inhibitor therapy may be pertinent to healing high grade esophagitis, its applicability to other GERD phenotypes wherein the modulating effects of anxiety, motility, hypersensitivity, and non-esophageal factors may dominate is highly questionable.

Gastrointestinal pharmacology: practical tips for the esophagologist

Gastroesophageal reflux disease (GERD) is primarily a motor disorder, and its pathogenesis is multifactorial. As a consequence, treatment should be able to address the underlying pathophysiology. Proton pump inhibitors (PPIs) are the mainstay of medical therapy for GERD, but these drugs only provide the control of symptoms and lesions without curing the disease. However, continuous acid suppression with PPIs is recommended for patients with Barrett's esophagus because of their potential chemopreventive effects. In addition to the antisecretory activity, these compounds display several pharmacological properties, often overlooked in clinical practice. PPIs can indeed affect gastric motility, exert a mucosal protective effect, and an antioxidant, anti-inflammatory, and antineoplastic activity, also protecting cancer cells from developing chemo- or radiotherapeutic resistance. Even in the third millennium, current pharmacologic approaches to address GERD are limited. Reflux inhibitors represent a promise unfulfilled, effective and safe prokinetics are lacking, and antidepressants, despite being effective in selected patients, give rise to adverse events in a large proportion of them. While waiting for new drug classes (like potassium-competitive acid blockers), reassessing old drugs (namely alginate-containing formulations), and paving the new avenue of esophageal mucosal protection are, at the present time, the only reliable alternatives to acid suppression.

Development prospects of curable osteoplastic materials in dentistry and maxillofacial surgery

The article presents classification of the thermosetting materials for bone augmentation. The physical, mechanical, biological, and clinical properties of such materials are reviewed. There are two main types of curable osteoplastic materials: bone cements and hydrogels. Compared to hydrogels, bone cements have high strength features, but their biological properties are not ideal and must be improved. Hydrogels are biocompatible and closely mimic the extracellular matrix. They can be used as cytocompatible scaffolds for tissue engineering, as can protein- and nucleic acid-activated structures. Hydrogels may be impregnated with osteoinductors such as proteins and genetic vectors without conformational changes. However, the mechanical properties of hydrogels limit their use for load-bearing bone defects. Thus, improving the strength properties of hydrogels is one of the possible strategies to achieve the basis for an ideal osteoplastic material.

Chewable Antacid Tablets: Are Disintegration Tests Relevant?

A recently published FDA guidance on chewable tablets has addressed the quality attributes of this class of dosage forms. This study evaluated disintegration as a quality attribute for a number of commercially available chewable antacid tablets. Additionally, acid-neutralizing-capacity values were evaluated. A number of the products exhibited prolonged disintegration times-which were far longer than those of conventional immediate-release tablets. The mean disintegration times ranged from 6 to more than 60 min in distilled water and from 9 to over 60 min in 0.1 N HCl. The products with longer disintegration times had higher breaking force and tensile strength values. Despite the range in disintegration times, all products met the criteria for acid-neutralizing capacity. These results indicate a need for patients to be aware of the need to thoroughly chew antacid tablets upon administration. Given these considerations, disintegration testing would be a useful quality control test in evaluating these dosage forms as the implicit assumption by the manufacturer that patients will chew the product sufficiently may not be met in every case.

A Brief Review of Nutraceutical Ingredients in Gastrointestinal Disorders: Evidence and Suggestions

The dietary effect on gut health has long been recognized through the empirical practice of soothing gastric discomfort with certain types of food, and recently the correlation between specific diets with lower incidences of several gastrointestinal diseases has been revealed. Ingredients from those considered beneficial foods have been isolated and studied, and some of them have already been put into the supplement market. In this review, we focus on latest studies of these food-derived ingredients for their proposed preventive and therapeutic roles in gastrointestinal disorders, with the attempt of drawing evidence-based suggestions on consuming these products.

Development and characterization of novel ambroxol sustained-release oral suspensions based on drug-polymeric complexation and polymeric raft formation

The aim was to develop sustained-release aqueous suspensions of ambroxol utilizing drug-polymer complexation and raft-forming formulations. Ambroxol-carrageenan (ABX-CRG) complexation was studied for the optimum binding capacity, which was used to prepare the complex by kneading and coprecipitation. The prepared complex was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry and powder X-ray diffractometry. The complex was formulated as suspensions in aqueous raft-forming vehicle of sodium alginate (NA) and calcium carbonate (CC). The suspensions differed in the molecular weight and concentration of NA, in addition to CC level and inclusion of CRG in excess of drug-polymer complexation. In 0.1 M HCl as simulated gastric fluid, the suspensions were observed for their ability to form rafts and studied for drug-release. The optimum sustained-release, raft forming and pourable formulation using high molecular weight NA, NA concentration of 18 mg/ml and CC concentration of 9 mg/ml was reached. Another optimum suspension was obtained by replacement of CC with excess CRG. However, pH dissolution profiles of the optimum suspensions revealed less pH sensitivity of the release consequent to this replacement as well as more stable ABX release upon aging. Relative to Gaviscon liquid, the optimum suspensions formed rafts of similar strength and higher resilience.

Investigation of the Role of the Alkalizing Agent in Sodium Alginate Liquid Anti-reflux Suspension

Background:

Anti-reflux formulation is one of the popular formulations across the globe in the pharmaceutical industry used specifically for the management of gastro-oesophageal reflux disease. But, this formulation is less explored with respect to research. Anti-reflux formulation has challenges to show its antacid functionality, which could have synergies in the management of refluxes in gastro-oesophageal reflux disease. Alkalizing agents act as antacid and improve the acid neutralization capacity in the anti-reflux formulation, and can be used appropriately as they affect raft strength beyond certain (optimum) limits.

Objective:

The objective of this work is to investigate the significance of alkalizing agent in sodium alginate based on oral liquid anti-reflux suspension for the management of Gastro-oesophageal Reflux Disease (GERD).

Methods:

In the present study, the formulation was prepared using sodium alginate along with different alkalizing agents like calcium carbonate and sodium bicarbonate at different levels. The formulation was further studied for in-vitro characterization like pH, viscosity, Acid Neutralization Capacity (ANC), thickness, formation speed, flotation, and raft strength.

Results:

The formulation with a higher level of calcium carbonate as the alkalizing agent showed a positive effect on the acid neutralization capacity (20.83mEq) and raft strength (16.95g) as well. Whereas, the formulation with a higher level of sodium bi-carbonate (4.01%) showed improved acid neutralization (22.31mEq) but showed a negative effect on raft strengths (10.08g).

Conclusion:

Based on the study, the optimum levels include 5% sodium alginate, 1.6% calcium carbonate and 2.67% sodium bicarbonate to achieve good liquid suspension formulation possessing good acid neutralization capacity as well as raft strength.

Diverse Applications of Marine Macroalgae

The aim of this paper is to review the multiplicity of the current uses of marine macroalgae. Seaweeds are already used in many products and for different purposes, from food products to medicine. They are a natural resource that can provide a number of compounds with beneficial bioactivities like antioxidant, anti-inflammatory, anti-aging effects, among others. Despite studies directed in prospecting for their properties and the commodities already marketed, they could, surely, be even more researched and sustainably explored.

Raft-forming gastro-retentive formulations based on Centella asiatica extract-solid dispersions for gastric ulcer treatment

Liquid raft-forming formulations comprising solid dispersions of glycoside-rich Centella asiatica extract and Eudragit® EPO (GR-SD) were developed to achieve prolonged delivery of the glycosides, asiaticoside (AS) and madecassoside (MS) in the stomach and thus increase the effectiveness of gastric ulcer treatment. Solid dispersions of GR extract and Eudragit® EPO (GR-SD, weight ratio 1:0.5) resulted in the highest solubility of AS (41.7 mg/mL) and MS (29.3 mg/mL) and completed dissolution of both glycosides occurred in SGF within 10 min. The optimized raft-forming formulation was composed of alginate (2%), HPMC K-100 (0.5%), GR-SD (1.2%), and calcium carbonate (0.5%) as a calcium source and carbon dioxide producer. The formulation provided sufficient raft strength (> 7.0 g), rapid floating behavior in SGF (~30 s), and sustained release of AS (more than 80%) and MS (85%) over 8 h. GR-SD-based formulations administered once daily to rats for two days at a dose of 10 mg AS/kg reduced the severity of gastric ulcer induced by indomethacin with a greater curative efficacy than those of unformulated GR extract and a standard antiulcer agent: lansoprazole (p < 0.05). These findings demonstrate that GR-SD-based raft-forming systems offer significant promise for improving the treatment of gastric ulcers induced by non-steroidal anti-inflammatory drugs.

The Clinical Efficacy of a Pure Alginate Formulation (Lamina G) for Controlling Symptoms in Individuals with Reflux Symptoms: A Randomized Clinical Study

Background/Aims

Bicarbonate-containing alginate formulations are reported to be effective for controlling reflux symptoms. However, the efficacy of Lamina G alginate without gas production has not been reported. The aim is to evaluate the efficacy of a non-bicarbonate alginate in individuals with reflux symptoms without reflux esophagitis.

Methods

Participants who had experienced heartburn or regurgitation for 7 consecutive days were randomized to one of the following treatment groups: proton pump inhibitors (PPI) plus alginate (combination) or PPI plus placebo (PPI only). In addition, as a reference group, patients received placebo plus alginate (alginate only). The primary endpoint compared the percentage of patients with complete resolution of symptoms for the final 7 days of the treatment. Secondary endpoints compared changes in symptom score, symptom-free days during the treatment period, the Reflux Disease Questionnaire, Patient Assessment of Upper Gastrointestinal Disorders (PAGI)-Quality of Life and PAGI-Symptoms Severity Index scores, the investigator’s assessment of symptoms, and incidence of adverse events.

Results

Complete resolution of heartburn or regurgitation was not significantly different between the combination and PPI only groups (58.7% vs 57.5%, p=0.903). The secondary endpoints were not significantly different between the two groups. Complete resolution of heartburn or regurgitation, did not differ between the alginate only reference group and the PPI only group (75.0% vs 57.5%, p=0.146).

Conclusions

The addition of non-bicarbonate alginate to PPI was no more effective than PPI alone in controlling reflux symptoms.

Formulation, optimization, and evaluation of raft-forming formulations containing Nizatidine

OBJECTIVE

The main objective of this research is to formulate, optimize, and evaluate raft-forming chewable tablets of Nizatidine. Various raft-forming agents were used in preliminary screening. Sodium alginate showed maximum raft strength, so tablets were prepared using sodium alginate as the raft forming agent, along with calcium carbonate (CaCO₃) as antacid and raft strengthening agent, and sodium bicarbonate (NaHCO₃) as a gas generating agent.

RESEARCH DESIGN AND METHODS

Raft forming chewable tablets containing Nizatidine were prepared by direct compression and wet granulation methods, and evaluated for drug content, acid neutralization capacity, raft strength, and in-vitro drug release in 0.1 N HCl. Box-Behnken design was used for optimization.

RESULTS

Two optimized formulations were predicted from the design space. The first optimized recommended concentrations of the independent variables were predicted to be X₁ = 275.92 mg, X₂ = 28.60 mg, and X₃ = 202.14 mg for direct compression technique and the second optimized recommended concentrations were predicted to be X₁ = 253.62 mg, X₂ = 24.60 mg, and X₃ = 201.77 mg for wet granulation technique. Optimized formulations were stable at accelerated environmental testing for six months at 35 °C and 45 °C with 75% relative humidity. X-Ray showed that the raft floated immediately after ingestion and remained intact for ∼3 h.

CONCLUSION

Raft was successfully formed and optimized. Upon chewing tablets, a raft is formed on stomach content. That results in rapid relief of acid burning symptoms and delivering the drug into systemic circulation with enhanced bioavailability.

Proton Pump Inhibitor-Refractory Gastroesophageal Reflux Disease

Proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) is defined by the presence of troublesome GERD symptoms despite PPI optimization for at least 8 weeks in the setting of ongoing documented pathologic gastroesophageal reflux. It arises from a dysfunction in protective systems to prevent reflux and as propagation of physiologic reflux events. Treatment possibilities include pharmacologic options, invasive management strategies, and endoluminal therapies. Management strategy should be personalized to the patient's needs and mechanistic dysfunction. This article reviews the definition, mechanisms, and management options for PPI-refractory GERD.

Recent Advances in Pharmaceutical Potential of Brown Algal Polysaccharides and their Derivatives

Marine plants, animals and microorganisms display steady growth in the ocean and are abundant carbohydrate resources. Specifically, natural polysaccharides obtained from brown algae have been drawing increasing attention owing to their great potential in pharmaceutical applications. This review describes the structural and biological features of brown algal polysaccharides, including alginates, fucoidans, and laminarins, and it highlights recently developed approaches used to obtain the oligo- and polysaccharides with defined structures. Functional modification of these polysaccharides promotes their advanced applications in biomedical materials for controlled release and targeted drug delivery, etc. Moreover, brown algal polysaccharides and their derivatives possess numerous biological activities with anticancer, anticoagulant, wound healing, and antiviral properties. In addition, we also discuss carbohydrate- based substrates from brown algae, which are currently in clinical and preclinical studies, as well as the marine drugs that are already on the market. The present review summarizes the recent development in carbohydratebased products from brown algae, with promising findings that could rapidly facilitate the future discovery of novel marine drugs.

Two placebo-controlled crossover studies in healthy subjects to evaluate gastric acid neutralization by an alginate-antacid formulation (Gaviscon Double Action)

OBJECTIVE

To investigate the intragastric acid neutralization activity of a combined alginate-antacid formulation.

SIGNIFICANCE

Published studies have investigated the reflux-suppressing alginate component of Gaviscon Double Action (Gaviscon DA; RB, UK) but intragastric acid neutralization activity of the antacid component has not been evaluated in vivo.

METHODS

Intragastric pH monitoring, using a custom-made 10-electrode catheter, was evaluated in a two-part exploratory study in healthy subjects; Part I (n = 6) tested suitability of the catheter using antacid tablets (Rennie; Bayer, Germany); Part II (n = 12) evaluated gastric acid neutralization activity of Gaviscon DA liquid (20 ml) versus placebo in fasted subjects using a randomized, open-label, crossover design. The primary endpoint was the percentage of time that intragastric pH ≥4 was measured during 30 min post-treatment. A confirmatory study of identical design was subsequently conducted (n = 20).

RESULTS

Monitoring pH using the multielectrode catheter was a viable approach, directly detecting changes in intragastric pH following a single dose of antacid tablets. In the exploratory study, the percentage of time that pH ≥4 during 30 minutes post-treatment was 46.8% with Gaviscon DA liquid versus 4.7% with placebo (p = 0.0004). These findings were supported by the confirmatory study, where pH ≥4 was recorded 50.8% of the time with Gaviscon DA versus 3.5% with placebo (p = 0.0051). In this study, Gaviscon DA was safe and well tolerated.

CONCLUSIONS

These studies demonstrate the effective acid neutralizing capacity of Gaviscon DA versus placebo in healthy, fasted subjects. This adds to the evidence base for the combination of alginates and antacids.

Re-evaluation of propane-1,2-diol alginate (E 405) as a food additive

The present opinion deals with the re‐evaluation of propane‐1,2‐diol alginate (E 405) when used as a food additive. The Panel noted that absorption, distribution, metabolism and excretion (ADME) data on propane‐1,2‐diol alginate gave evidence for the hydrolysis of this additive into propane‐1,2‐diol and alginic acid. These two compounds have been recently re‐evaluated for their safety of use as food additives (EFSA ANS Panel, 2017, 2018). Consequently, the Panel considered in this opinion the major toxicokinetic and toxicological data of these two hydrolytic derivatives. No adverse effects were reported in subacute and subchronic dietary studies with propane‐1,2‐diol alginate. The available data did not indicate a genotoxic concern for propane‐1,2‐diol alginate (E 405) when used as a food additive. Propane‐1,2‐diol alginate, alginic acid and propane‐1,2‐diol were not of concern with respect to carcinogenicity. The Panel considered that any adverse effect of propane‐1,2‐diol alginate would be due to propane‐1,2‐diol. Therefore, the acceptable daily intake (ADI) of the food additive E 405 is determined by the amount of free propane‐1,2‐diol and the propane‐1,2‐diol released from the food additive after hydrolysis. According to the EU specification, the concentration of free and bound propane‐1,2‐diol amounts to a maximum of 45% on a weight basis. On the worst‐case assumption that 100% of propane‐1,2‐diol would be systemically available and considering the ADI for propane‐1,2‐diol of 25 mg/kg body weight (bw) per day, the Panel allocated an ADI of 55 mg/kg bw per day for propane‐1,2‐diol alginate. The Panel concluded that exposure estimates did not exceed the ADI in any of the population groups from the use of propane‐1,2‐diol alginate (E 405) as a food additive. Therefore, the Panel concluded that there is no safety concern at the authorised use levels.

The Effect of Alginate in Gastroesophageal Reflux in Infants

BACKGROUND

Guidelines are contradictory regarding the use of alginate in infants with persisting gastroesophageal reflux (GER). While The British National Institute for Health and Care (NICE) guidelines consider alginate as a treatment option, the guidelines of the European and North-American Societies for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN, NASPGHAN) do not recommend alginates.

AIMS

We assessed the efficacy of alginate to reduce GER episodes in infants.

METHODS

In a prospective, observational study, we consecutively enrolled all infants referred for pH-multiple intraluminal impedance (pH-MII) recording because of persisting GER symptoms not responsive to behavior and dietetic modifications. A 48-h pH-MII was performed in all infants; a baseline recording was performed during the first 24 h while magnesium or sodium alginate was administered during the second 24 h. The primary endpoint was the difference in the total number of GER episodes per 24 h between the baseline day and the second day during which the alginate was administered. The secondary outcome was the difference in symptoms between each period. We also compared other pH-MII data from before and during alginate administration.

RESULTS

We recruited 43 infants (median age 68 days, range 25-306); three pH-MII tracings were excluded because of artifacts. The median number of all MII reflux episodes was significantly reduced during alginate administration (76.0 vs 69.5; p < 0.001). Crying-fussiness, cough and regurgitation episodes all significantly improved during alginate administration (p = 0.00012; p = 0.005 and p = 0.04, respectively). The following MII parameters also decreased during the alginate administration: acid (19.0 vs 14.5; p < 0.04), non-acid (52.0 vs 49.5; p < 0.004), proximal GER episodes (46.0 vs 41.4; p < 0.007), and bolus exposure index (1.9 vs 1.6; p = 0.002). At least three out of seven pH-MII parameters decreased by > 10% during the alginate period in 31/40 infants (77.5%), without a significant difference between magnesium and sodium alginate.

CONCLUSION

These results suggest that alginate significantly decreases the number and extension of both acid and non-acid reflux episodes and associated symptoms in infants.

[The prospects of hydrogels usage as a basis for curable osteoplastic materials]

The article deals with the main types of the polymers used in hydrogel preparation. Their biological, physical and chemical properties was compared. Ways of polymers hardening and prospects of medical application were considered. The prospect of use of chitosan hydrogels activated by osteoinductors as a material for bone augmentation were concluded.

Recent Advances in the Pharmacological Management of Gastroesophageal Reflux Disease

The management of proton pump inhibitor-refractory GERD (rGERD) is a challenge in clinical practice. Since up to one-third of patients with typical GERD symptoms (heartburn and/or acid regurgitation) are not satisfied with proton pump inhibitor (PPI) therapy, new drug development targeting different pathophysiologies of GERD is imperative. At present, no other drugs serve as a more potent acid suppression agent than PPIs. As an add-on therapy, histamine type-2 receptor antagonists, alginates, prokinetics and transient lower esophageal sphincter relaxation inhibitors have some impact on the subgroups of rGERD, but greater effectiveness and fewer adverse effects for widespread use are required. Visceral hypersensitivity also contributes to the perception of GERD symptoms, and neuromodulators including antidepressants play a role in this category. Esophageal pH-impedance monitoring helps to distinguish functional heartburn from true GERD, and psychologic medication and cognitive behavior therapy are further therapy options instead of PPIs.

Re-evaluation of alginic acid and its sodium, potassium, ammonium and calcium salts (E 400-E 404) as food additives

The present opinion deals with the re-evaluation of alginic acid and its sodium, potassium, ammonium and calcium salts (E 400-E 404) when used as food additives. Alginic acid and its salts (E 400-E 404) are authorised food additives in the EU in accordance with Annex II and Annex III to Regulation (EC) No 1333/2008. Following the conceptual framework for the risk assessment of certain food additives re-evaluated under Commission Regulation (EU) No 257/2010, the Panel concluded that there was no need for a numerical Acceptable Daily Intake (ADI) for alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404), and that there was no safety concern at the level of the refined exposure assessment for the reported uses of alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404) as food additives. The Panel further concluded that exposure of infants and young children to alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404) by the use of these food additives should stay below therapeutic dosages for these population groups at which side-effects could occur. Concerning the use of alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404) in 'dietary foods for special medical purposes and special formulae for infants' (Food category 13.1.5.1) and 'in dietary foods for babies and young children for special medical purposes as defined in Directive 1999/21/EC' (Food category 13.1.5.2), the Panel further concluded that the available data did not allow an adequate assessment of the safety of alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404) in infants and young children consuming the food belonging to the categories 13.1.5.1 and 13.1.5.2.

Effect of alginate in patients with GERD hiatal hernia matters

Alginate-based formulations are frequently used as add-on proton pump inhibitor (PPI) therapy to help control of heartburn and regurgitation. There are limited data regarding the mechanisms and effects of alginate-based formulations. We aimed to evaluate the effects of the sodium alginate intake and its likely temporal relations on intraesophageal reflux events by MII-pH in patients with and without hiatal hernia (HH). Fifty GERD patients (18 with HH, 32 without HH) with heartburn or regurgitation once a week or more common were included. After combined multichannel intraluminal impedance and pH-metry (MII-pH) had been performed, all patients were asked to eat the same standard meal (double cheeseburger, 1 banana, 100 g regular yoghurt, and 200 mL water with total energy value of 744 kcal: 37.6% of carbohydrates, 21.2% of proteins, and 41.2% of lipids) during two consecutive days. On separate random two consecutive days, all patients took 10 mL of sodium alginate (GA; Gaviscon Advance; Reckitt Benckiser Healthcare, Hull, UK) or 10 mL of water, 30 minutes after the refluxogenic meal. After eating refluxogenic meal, patients were examined ½ hour for basal conditions, 1 hour in upright, and 1 hour in supine positions. Alginate significantly decreased acid reflux after intake at the first hour in comparison to water in patients with HH (6.1 vs. 13.7, P = 0.004) and without HH (3.5 vs. 5.5, P = 0.001). Weakly acid reflux were increased at the first hour in patients with HH (3.4 vs. 1.3, P = 0.019) and without HH (1.7 vs. 5, P = 0.02) compared to water. There was no distinctive effect of alginate on the height of proximal migration of reflux events in patients with HH and without HH. Alginate decreases acid reflux events within a limited time period, especially at the first hour both in patients with and without HH. Alginate has no effect on the height of reflux events along the esophagus both in patients with and without HH.