Maja Stojančević

The impact of farnesoid X receptor activation on intestinal permeability in inflammatory bowel disease

The most important function of the intestinal mucosa is to form a barrier that separates luminal contents from the intestine. Defects in the intestinal epithelial barrier have been observed in several intestinal disorders such as inflammatory bowel disease (IBD). Recent studies have identified a number of factors that contribute to development of IBD including environmental triggers, genetic factors, immunoregulatory defects and microbial exposure. The current review focuses on the influence of the farnesoid X receptor (FXR) on the inhibition of intestinal inflammation in patients with IBD. The development and investigation of FXR agonists provide strong support for the regulatory role of FXR in mucosal innate immunity. Activation of FXR in the intestinal tract decreases the production of proinflammatory cytokines such as interleukin (IL) 1-beta, IL-2, IL-6, tumour necrosis factor-alpha and interferon-gamma, thus contributing to a reduction in inflammation and epithelial permeability. In addition, intestinal FXR activation induces the transcription of multiple genes involved in enteroprotection and the prevention of bacterial translocation in the intestinal tract. These data suggest that FXR agonists are potential candidates for exploration as a novel therapeutic strategy for IBD in humans.

Application of bile acids in drug formulation and delivery

Bile acids are naturally produced in humans and are known to provide human health benefits through their endocrinological, microfloral, metabolic and other åffects that are still to be elucidated. In recent years, there has been a growing interest in using bile acids as absorption enhancers for drug delivery. Bile acids are amphiphilic molecules with a unique ability to facilitate and promote drug permeation through biological membranes. The role of bile acids in promoting drug permeation has been experimentally illustrated in various pharmaceutical formulations including oral, nasal, ocular, buccal, pulmonary and rectal delivery as well as through the blood–brain barrier. Recently, bile acids have drawn attention in the field of drug delivery due to their ability to act as a drug carrier system in the form of mixed micelles, bilosomes and chemical conjugates with drug molecules. Bile acids have demonstrated a unique ability to enhance the epithelial transport of hydrophilic drugs through the paracellular route and that of hydrophobic compounds through both paracellular and transcellular routes. The aim of this review is to discuss various chemical and pharmaceutical aspects of BAs and their potential applications in drug formulation and delivery.

An advanced microencapsulated system: a platform for optimized oral delivery of antidiabetic drug-bile acid formulations

Abstract Introduction: In previous studies, we have shown that a gliclazide–cholic acid derivative (G–CA) mixture resulted in an enhanced ileal permeation of G (ex vivo). When administered orally to diabetic rats, it brought about a significant hypoglycaemic effect. In this study, we aim to create a novel microencapsulated-formulation of G–CA with uniform and coherent structure that can be further tested in our rat model of type 1 diabetes (T1D). We also aim to examine the effect of CA addition to G microcapsules in the morphology, structure and excipients’ compatibility of the newly designed microcapsules. Method: Microencapsulation was carried out using our Buchi-based microencapsulating system developed in our laboratory. Using sodium alginate (SA) polymer, both formulations were prepared: G–SA (control) and G–CA–SA (test) at a constant ratio (1:3:30), respectively. Complete characterizations of microcapsules were carried out. Results: The new G–CA–SA formulation is further optimized by the addition of CA exhibiting pseudoplastic-thixotropic rheological characteristics. Bead size remains similar after CA addition, the new microcapsules show no chemical interactions between the excipients and this was supported further by the spectral studies suggesting bead stability. Conclusion: The new microencapsulated-formulation has good and uniform structural properties and may be suitable for oral delivery of antidiabetic-bile acid formulations.

An Insight on Differences in Availability and Reimbursement of Orphan Medicines Among Serbia, Bulgaria and Sweden

ABSTRACT In the European Union (EU), rare diseases are defined as life-threatening or chronically debilitating diseases with prevalence lower than five in 10,000 inhabitants. Although individually rare, together, rare diseases affect a significant part of the population (27–36 million people in the EU). Therefore, patient access to orphan medicines is receiving increasing political attention in the EU. In order to assess the differences in availability of reimbursed orphan medicines among Serbia, Bulgaria and Sweden, National Reimbursement Lists were reviewed and identified orphan medicines were crossed with the List of orphan drugs in Europe, published in July 2011, available from Orphanet. The analysis of regulatory traits was based mainly on a review of the official documents setting out legislation regarding rare diseases and orphan medicines in the studied countries. Only 6.5% (4 out of 61) of the authorised orphan medicines in Europe with prior orphan designation and 25.0% (17 out of 68) without prior orphan designation were available and reimbursed in Serbia. In the Bulgarian Positive Drug List 44.3% (27 out of 61) of the drugs with prior orphan designation and 50.0% (34 out of 68) without prior orphan designation were identified. The share of reimbursed orphan medicines was the highest in Sweden among the observed countries—52.5% (32 out of 61) of the medicines with orphan designation and 60.3% (41 out of 61) without prior orphan designation. According to the first level of the ATC Classification System, most of the reimbursed orphan medicines in the three studied countries belonged to the group L: “Antineoplastic and immunomodulating agents”, while the most common indications for authorised and reimbursed orphan medicines were “Neoplasms” (C00-D48), with 19 available orphan drugs in Serbia, 26 in Sweden and 31 in Bulgaria. Inequities in the access to orphan medicines among Serbia, Bulgaria and Sweden may be explained by the differences in the approaches for registration, pricing and reimbursement of orphan medicines. The low share of reimbursed orphan drugs in Serbia may be due to incomplete compliance with EU legislation and existence of domestic procedure for authorisation as well. The EU legislation and policy on treatment of rare diseases obviously facilitate the penetration of orphan drugs on the EU market, but apparently there is also considerable budget impact on the availability of reimbursed orphan medicines.

Remarkably lower consumption of antidepressants in Serbia in comparison with Finland

Background Depression is an important health problem worldwide due to significant disability that it causes, reduction of quality of life, loss of work days, and even suicide. The aim of our survey was to evaluate the overall utilization and pattern of use of antidepressants in Serbia in a comparison with Finland in 2010 and to propose appropriate interventions in Serbia on the basis of the results obtained.

Differences in the use of medicines for peptic ulcer and gastro-esophageal reflux disease between Serbia, Croatia and Sweden

Results The overall consumption of medicines from A02B subgroup in 2010 in Serbia was 22.9 DID, whereas in Croatia and Sweden was 32.8 DID and 48.6 DID, respectively. In Serbia, H2RAs accounted for 71.8% (16.5 DID) of medicines used within A02B subgroup, while in Croatia H2RAs accounted for 37.3% (12.2 DID) and in Sweden 2.2% (1.1 DID). In the same year, the utilization of PPIs in Serbia (6.5 DID) was more than three times lower than in Croatia (20.6 DID) and more than seven times lower than in Sweden (47.3 DID). The bulk of prescription (DU90%) was made up of 3 (out of 7) medicines in Serbia, 5 (out of 8) medicines in Croatia and 5 (out of 14) medicines in Sweden. The most frequently used medicine from the A02B subgroup in Serbia was ranitidine (56.0%, i.e. 12.8 DID), in Croatia pantoprazole (36.5%, i.e.12.0 DID) and in Sweden omeprazole (81.3%, i.e. 39.0 DID).

Considerable differences in the utilisation of antidiabetics between Serbia and Scandinavian countries

Background Diabetes mellitus is a major public health concern with devastating human, social and economic impact. It is increasing globally, affecting more than 180 million people worldwide. The objective of our study was to analyse the overall volume of use of antidiabetics in Serbia compared to Scandinavian countries (Sweden, Norway, Denmark), chosen for their rational and conservative prescription practice. Methods Data on consumption of antidiabetics (ATC group A10) in 2010 were extracted from the databases of the representative national authorities. Utilisation of these medicines was measured through the defined daily dose (DDD) unit and the results were expressed as DDD per 1000 inhabitants per day (DID). Results In 2010, antidiabetics were used at a similar rate in Serbia (47.3 DID) and Scandinavian countries (from 46.5 DID in Sweden to 47.67 DID in Norway), but the share of use of insulins (A10A) and oral antidiabetics (A10B) differed among the observed countries. The proportion of insulin in Serbia was 22.0% of all antidiabetics which is relatively low in comparison with Scandinavian countries (from 36.2% in Denmark to 50.8% in Sweden). Utilisation of long-acting insulins (A10AE) was much lower in Serbia (1.3 DID) compared to Scandinavian countries (range: 2.6–4.6 DID). The share of oral antidiabetics use also differed among these countries. In Serbia, sulfonylureas (A10BB), as a second-line treatment for type 2 diabetes, were used predominantly (55.6%) compared to metformin (44.1%). In Scandinavian countries, metformin, as preffered oral agent for type 2 diabetes and the only medicine from the biguanide class (A10BA), was used at a higher rate than in Serbia (from 51.2% in Denmark to 60.4% in Sweden). New medicinal products with effect on the incretin system (A10BH and A10BX) were also used at a higher rate in Scandinavian countries (range: 0.5–2.5 DID) in comparison to Serbia (0.002 DID). Conclusions