Incompatibility of antimalarial drugs: challenges in formulating combination products for malaria

Lipophilic drugs require more advance formulation, especially if the intention is to make solutions or semisolid formulations. This also accounts for most antimalarial drugs. Although some of these antimalarial drugs are soluble in lipid vehicles, few of them, such as lumefantrine (LF), are also poorly soluble in oily vehicles. Trying to dissolve and formulate LF as a liquid formulation together with other antimalarial drugs is, therefore, a major task. When mixed in solution together with artemether (AR), precipitation occurs, sometimes with LF precipitating out on its own, and sometimes with AR precipitating out alongside LF. In this study, it was hypothesized that the use of fatty acids could lead to enhanced solubility in lipid formulation. Addition of the fatty acid solved the dissolution challenges, making LF soluble for over a year at room temperature (21-23 °C); but further research is needed to test the mechanism of action of the fatty acid. In addition, design of experiments (MODDE® 13) revealed that the amount of fatty acid in the formulation was the only significant factor for LF precipitation.

Compliance and illiteracy when treating tuberculosis

According to Centers for Disease Control and Prevention, one-fourth of the worlds' population was infected with tuberculosis (TB) in 2017. It is estimated that globally, more than 1 billion woken are infected with TB. The treatment of TB is limited to follow the treatment schedule. A small pause in taking the meds, forgetting the meds for a day or two etc will result in relapse of the disease. Unfortunately, illiteracy is associated with poor compliance and understanding of the importance of following the treatment protocol. In 2015, it was estimated that about 11% of the world's population over 15 y were illiterate. Where two-thirds were women. This is even worse in sub-Saharan Africa, where 34.7% of all adults above 15 y were illiterate in 2019.

Colour of Medicines and Children's Acceptability? A Systematic Literature Review of Children's Perceptions about Colours of Oral Dosage Forms

The colour of a product plays an important role in consumer experiences, and in the context of pharmaceutical products, this could potentially affect a patient's expectations, behaviours, and adherence. Several studies have been conducted on adults, but little is known about children's opinions on colours of medicines and to what extent medicines' colour affects their acceptability. To address this gap, a systematic search in PubMed, Scopus, MEDLINE, and Web of Science was conducted. Two authors independently screened the titles, abstracts, and references of all articles and selected studies conducted on children (0-18 years old), assessing children's preferences or opinions about colour of oral dosage forms as either a primary or secondary objective or as an anecdotal record. A total of 989 publications were identified and, after screening, 18 publications were included in the review. Red and pink were the most liked colours and there appeared to be a relationship between the colour of a medicine and expected taste/flavour. The review also highlighted a scarcity of information, usually collected as an anecdotal record. Several gaps in the current knowledge were underlined, emphasizing the need of patient-centred studies to understand if the use of certain colours can improve or worsen the acceptability of a paediatric medicine. This will help inform pharmaceutical manufacturers and regulators on the role and need of colours in children's medicines beyond quality purposes.

Estimation of Pediatric Dosage of Antimalarial Drugs, Using Pharmacokinetic and Physiological Approach

Most of the individuals who die of malaria in sub-Saharan Africa are children. It is, therefore, important for this age group to have access to the right treatment and correct dose. Artemether-lumefantrine is one of the fixed dose combination therapies that was approved by the World Health Organization to treat malaria. However, the current recommended dose has been reported to cause underexposure or overexposure in some children. The aim of this article was, therefore, to estimate the doses that can mimic adult exposure. The availability of more and reliable pharmacokinetic data is essential to accurately estimate appropriate dosage regimens. The doses in this study were estimated using the physiological information from children and some pharmacokinetic data from adults due to the lack of pediatric pharmacokinetic data in the literature. Depending on the approach that was used to calculate the dose, the results showed that some children were underexposed, and others were overexposed. This can lead to treatment failure, toxicity, and even death. Therefore, when designing a dosage regimen, it is important to know and include the distinctions in physiology at various phases of development that influence the pharmacokinetics of various drugs in order to estimate the dose in young children. The physiology at each time point during the growth of a child may influence how the drug is absorbed, gets distributed, metabolized, and eliminated. From the results, there is a very clear need to conduct a clinical study to further verify if the suggested (i.e., 0.34 mg/kg for artemether and 6 mg/kg for lumefantrine) doses could be clinically efficacious.

The effect of D-(+)-glucosamine, N-acetyl-D-glucosamine and tetraethylene glycol on the stability of oxytocin in aqueous solution

The aim of the present study was to identify the effect of D-(+)-glucosamine, N-acetyl-D-glucosamine, tetraethyleneglycol, and the mixture of these additives on the stability of oxytocin in phosphate and acetate buffer solutions, at pH 4.5. Our findings demonstrate that tetraethyleneglycol has a destabilizing effect on oxytocin in both phosphate buffer and acetate buffer. D-(+)-Glucosamine hydrochloride had small to negligible effect at low concentrations, yielding a slight improvement lower concentrations of the additive in the presence of the buffers used, but at higher concentrations it increased the rate of degradation. N-Acetyl-D-glucosamine showed a possibly slight improvement to the stability of oxytocin. It is hypothesized that the different effect of N-acetyl-D-glucosamine compared to D-(+)-glucosamine is a consequence of the free amine group in D-(+)-glucosamine promoting a faster degradation, while the amino group is acetylated in N-acetyl-D-glucosamine and therefore no longer reactive in the same way. While it remains unclear why tetraethyleneglycol has a destabilizing effect on oxytocin, the D-(+)-glucosamine results aid in deepening our understanding of the degradation mechanism of oxytocin.

Atrial fibrillation substrate mapping with decrement evoked potential mapping

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Sociedad Española de Cardiologia.

OnBehalf

DEFINE-AF

Background

Identifying and targeting atrial substrate zones that are vulnerable to unidirectional block and slow conduction may be critical to improve the outcomes of atrial fibrillation (AF) ablation. Functional mapping of the atrial substrate with Decrement Evoked Potential (DeEP) and a single extrastimulus in this population could potentially lead to novel therapeutic strategies.

Aim

1) To systematically analyze whether the DEEP are present in the atrial tissue and their locations after pulmonary vein isolation. 2) To assess their relationship with the underlying voltage.  3) To assess the presence of DEEP as a function of the subtype of AF.

Methods

Consecutive patients with AF undergoing ablation were prospectively enrolled at 3 institutions. A biatrial voltage map was created and after pulmonary vein isolation (PVI). A drive train and an extrastimulus (atrial refractory period + 20ms) was delivered from an epicardial site (proximal CS) and an endocardial site (left atrial appendage (LAA). A multipolar mapping catheter was sequentially placed at 8 left atrial sites and 5 right atrial sites. Electrograms (EGMs) that showed a local delay of >10ms in activation with the extrastimulus were identified as DEEPs. Patients were followed for a mean of 11 ± 5 months

Results

74 patients, 63 pers AF (85%), mean age 62 ± 8, mean LA size 41 ±12 mm were enrolled. Of 19240 EGMs analyzed, 8.2% showed DEEPs (54.6% with CS pacing and 45.4% with LAA pacing, p = 0.0001). The mean local decrement seen was 39 ms. Most DEEPs (76.2%) were identified in sites with a normal EGM at baseline with preserved voltages. DEEPs were differentially distributed within the regions mapped, more frequently in LA than RA (9.2% vs 6.6%, p < 0.0001). Patients with persistent AF had a higher proportion of DEEPs than patients with paroxysmal AF (9.7% vs 5.1%, p < 0.001).

Conclusions

Atrial DEEPs are: 1) More often identified when pacing endocardially. 2) More common in patients with persistent AF. 3) More frequent in the LA than in the RA. 4) Mostly located in regions with normal voltages at baseline. All those findings suggest the importance of the functional substrate mapping in the atrium and could lead to novel therapeutic targets. Abstract Figure. Example of atrial DEEP

Effect of 18-Crown-6 on Oxytocin Stability in Aqueous Buffer Solutions

In this study, the effect of 18-crown-6 on the stability of oxytocin in aqueous solution was explored. The study found that while 12-crown-4 and 15-crown-5 do not stabilize oxytocin, 18-crown-6 does have a stabilizing effect in citrate/phosphate buffer at pH 4.5. However, in acetate buffer at the same pH, the presence of 18-crown-6 had a destabilizing effect, possibly leading to a different degradation pathway. Both the stabilizing and destabilizing effects, depending on the buffer used, are concentration dependent where a higher concentration of 18-crown-6 is linked to a stronger effect. It is hypothesized that this effect may be linked to 18-crown-6 binding to the protonated ammonium group of oxytocin. Upon changing the mobile phase used in high-performance liquid chromatography experiments, we observed evidence supporting this binding hypothesis. When an acidic mobile phase was used (0.01% trifluoroacetic acid (TFA)), a partial shift in oxytocin retention time was observed for samples in acetate buffers in the presence of 18-crown-6 when using a 150 mm column (C18). The amount of the peak that shifted depended on the 18-crown-6 concentration used. A similar shift in oxytocin peak retention time was observed for samples in both acetate and citrate/phosphate buffers when using a 250 mm column (C18), but the peak completely shifted in those samples. When using an even more acidic mobile phase (0.1% TFA), the oxytocin peaks all had the same retention time again. Ultraviolet and nuclear magnetic resonance spectroscopy experiments also showed that the presence of 18-crown-6 has an observable effect on the resulting oxytocin spectra.

Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study

The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.

Modulation of immune responses using adjuvants to facilitate therapeutic vaccination

Therapeutic vaccination offers great promise as an intervention for a diversity of infectious and non-infectious conditions. Given that most chronic health conditions are thought to have an immune component, vaccination can at least in principle be proposed as a therapeutic strategy. Understanding the nature of protective immunity is of vital importance, and the progress made in recent years in defining the nature of pathological and protective immunity for a range of diseases has provided an impetus to devise strategies to promote such responses in a targeted manner. However, in many cases, limited progress has been made in clinical adoption of such approaches. This in part results from a lack of safe and effective vaccine adjuvants that can be used to promote protective immunity and/or reduce deleterious immune responses. Although somewhat simplistic, it is possible to divide therapeutic vaccine approaches into those targeting conditions where antibody responses can mediate protection and those where the principal focus is the promotion of effector and memory cellular immunity or the reduction of damaging cellular immune responses as in the case of autoimmune diseases. Clearly, in all cases of antigen-specific immunotherapy, the identification of protective antigens is a vital first step. There are many challenges to developing therapeutic vaccines beyond those associated with prophylactic diseases including the ongoing immune responses in patients, patient heterogeneity, and diversity in the type and stage of disease. If reproducible biomarkers can be defined, these could allow earlier diagnosis and intervention and likely increase therapeutic vaccine efficacy. Current immunomodulatory approaches related to adoptive cell transfers or passive antibody therapy are showing great promise, but these are outside the scope of this review which will focus on the potential for adjuvanted therapeutic active vaccination strategies.

Evaluation of in vitro mucoadhesiveness and texture profile analysis of doxycycline in situ hydrogels

Delivery of active ingredients to the oral mucosa from topically applied formulations reduces side effects from systemic administration and enhances the treatment efficiency. The challenge however, is to maintain the formulation at the administration site due to rapid salivary flow and mechanical movements of the mouth. Therefore, addition of mucoadhesive polymers could aid in enhancing the formulation residence time by increasing the mucoadhesion capacity but this effect is negligible especially if low ratio of mucoadhesive polymers are added to the formulation. Different mucoadhesive polymers at 0.5% w/w (either single or combination of two polymers) were added to the hydrogels and tested for mucoadhesion capacity, tensile strengths, adhesiveness, cohesiveness, compressibility and hardness. 0.5% povidone showed significantly highest work of mucoadhesion, 0.5% Carbopol formulation showed least cohesiveness and 0.5% HPMC showed highest adhesiveness, but a formulation containing a combination of 0.25% HPMC and 0.25% povidone showed the ideal parameters among all the mucoadhesive polymers tested. The effect of increase in concentration of HPMC (0.5, 1, 1.5, 2%) showed linear relationship for work of mucoadhesion and tensile strengths whereas for TPA the values were non-linear. The drug release from the optimized polymer matrices was found to follow zero-order release profile and the mechanism was found to be super case-II transport relaxation release. The results of this study indicate the mucoadhesive polymers do not impact the tensile strengths (p =0.05), but the texture properties and work of mucoadhesion of the formulations can be significantly (p <0.05) altered by the choice of mucoadhesive component at 0.5%w/w, though not for all the polymers tested. The study provides scope to predict in vivo performance and helps optimize for localized delivery.

Long-term Stabilization of Aqueous Doxycycline Formulations, in Mucoadhesive Hydrogels for Treatment of Oral Mucosal Conditions

BACKGROUND

The main aim of this work was to develop stable (>2 years) doxycycline formulation, at clinically relevant concentrations and using clinically relevant formulation. Doxycycline has a MMP- inhibitory effects that is important for the treatment of various oral mucosal conditions. Therefore, protecting doxycycline from degradation in aqueous formulation requires halting or prevention of oxidation and epimerisation of the active compound.

METHODS

Stabilizing excipients were intuitively put together to enhance the stability as a cumulative effort. A total of 30 hydrogels were compared with different types and concentrations of stability enhancing excipients, pH, storage temperatures (4, 25 and 40°C) and mucoadhesive polymers. The duration of the study was from day 1 and up to 58 months. The gelation temperature was adjusted below the actual body temperature. The complexation efficiency between the doxycycline and HPβCD was studied using the DSC, FTIR and XRPD.

RESULTS

The majority of formulations at 4°C were highly stable by the end of 58 months and their stabilities were improved at all 3 temperatures.

CONCLUSION

In conclusion, it is possible to prevent doxycycline from both oxidation and epimerization in an aqueous formulation, for up to 5 years.

Doxycycline and Monocaprin In Situ Hydrogel: Effect on Stability, Mucoadhesion and Texture Analysis and In Vitro Release

The aim of this study was to develop a stable aqueous formulation containing a combination of doxycycline and monocaprin in clinically relevant concentrations. Increase in expression of Matrix metalloproteinases (MMPs) and microbial role in oral diseases is well established and the combination of above active ingredients could be potentially beneficial in treatment of oral mucosal conditions. The hydrogels containing different concentrations of doxycycline and monocaprin in the presence and absence of stabilizing excipients were developed and their stabilities were studied at 4 °C for up to 1 year. The drug-drug interaction was evaluated using Fourier-transform infrared spectroscopy (FTIR). The addition of monocaprin on doxycycline in situ hydrogel's mucoadhesiveness, texture properties and drug release mechanism was studied. The addition of monocaprin negatively affected the doxycycline stability and was concentration dependent, whereas monocaprin was stable up to 1 year. Doxycycline did not interfere with the anti-Candidal activity of monocaprin. Furthermore, the presence of monocaprin significantly affected the formulation hardness, compressibility and adhesiveness. Monocaprin and doxycycline release followed zero order kinetics and the release mechanism was, by anomalous (non-Fickian) diffusion. The addition of monocaprin increased the drug release time and altered the release mechanism. It is possible to stabilize doxycycline in the presence of monocaprin up to 1 year at 4 °C.

Aspirin causes endothelium-dependent vasodilation of resistance arteries from non-gravid and gravid rats

OBJECTIVE

The objective of this study was to understand the effect of acetylsalicylic acid (aspirin) on resistance arteries from mesentery and uterus. During pregnancy, the uterine vasculature undergoes consistent growth to provide sufficient uteroplacental blood flow, a process whose failure is associated with pregnancy complications characterized by high uterine vascular resistance.

METHODS

Uterine arcuate (UA) and mesenteric arteries (MA; diameter <300 µm) isolated from non-gravid, mid-gravid (day 14), and late-gravid rats (day 20) were exposed to aspirin (10^-12 to 10^-5 M). Further, in UA from late-gravid rats, aspirin was evaluated in presence of inhibitors of nitric oxide synthases, cyclooxygenase, cyclic nucleotides (cAMP, cGMP) and BK channels, and also on endothelium-denuded vessels.

RESULTS

Aspirin dilated both UA and MA in a dose dependent manner. Pregnancy increased aspirin vasodilation in MA and UA from mid-gravid rats, an effect that was reduced in vessels from late gravid animals at concentrations >10^-7 M. Further, uterine vasodilation was significantly reduced when the endothelium was removed (p < 0.001), and by inhibitors of nitric oxide synthase (p < 0.001), cyclooxygenase synthase (p < 0.05), cyclic nucleotides cGMP/cAMP and BK channels.

CONCLUSION

This is the first study to show a direct vasodilatory effect of aspirin on rat uterine artery that is mediated by a combination of cellular - primarily endothelial - mechanisms. Our results in UA suggest that the use of aspirin may be effective in enhancing uteroplacental blood flow, while its vasodilation effect on MA may lower peripheral resistance.

Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia

BACKGROUND

Preterm preeclampsia is an important cause of maternal and perinatal death and complications. It is uncertain whether the intake of low-dose aspirin during pregnancy reduces the risk of preterm preeclampsia.

METHODS

In this multicenter, double-blind, placebo-controlled trial, we randomly assigned 1776 women with singleton pregnancies who were at high risk for preterm preeclampsia to receive aspirin, at a dose of 150 mg per day, or placebo from 11 to 14 weeks of gestation until 36 weeks of gestation. The primary outcome was delivery with preeclampsia before 37 weeks of gestation. The analysis was performed according to the intention-to-treat principle.

RESULTS

A total of 152 women withdrew consent during the trial, and 4 were lost to follow up, which left 798 participants in the aspirin group and 822 in the placebo group. Preterm preeclampsia occurred in 13 participants (1.6%) in the aspirin group, as compared with 35 (4.3%) in the placebo group (odds ratio in the aspirin group, 0.38; 95% confidence interval, 0.20 to 0.74; P=0.004). Results were materially unchanged in a sensitivity analysis that took into account participants who had withdrawn or were lost to follow-up. Adherence was good, with a reported intake of 85% or more of the required number of tablets in 79.9% of the participants. There were no significant between-group differences in the incidence of neonatal adverse outcomes or other adverse events.

CONCLUSIONS

Treatment with low-dose aspirin in women at high risk for preterm preeclampsia resulted in a lower incidence of this diagnosis than placebo. (Funded by the European Union Seventh Framework Program and the Fetal Medicine Foundation; EudraCT number, 2013-003778-29 ; Current Controlled Trials number, ISRCTN13633058 .).

Placental Protein 13 Administration to Pregnant Rats Lowers Blood Pressure and Augments Fetal Growth and Venous Remodeling

Reduced first-trimester concentrations of placental protein 13 (PP13) are associated with subsequent development of preeclampsia, a major pregnancy disorder. We previously showed that PP13 has a vasodilatory effect, reduces blood pressure and augments expansive remodeling of the uteroplacental vasculature in pregnant rats. In this study, slow-release osmotic pumps were implanted in gravid rats (on day 8) to provide 1 week of PP13 supplementation. Treatment was associated with a reversible blood pressure reduction that returned to normal on day 15. In addition, PP13 caused venous expansion that is larger in the venous branches closer to the placenta. Then, it increased placental and pup weights. Similar administration of a truncated PP13 variant (DelT221) that is unable to bind carbohydrates (a rare spontaneous mutation associated with a high frequency of severe early preeclampsia among Blacks in South Africa) produced a hypotensive effect similar to the full-length molecule, but without venous remodeling and increased placental and pup weights. These results indicate the importance of PP13 carbohydrate binding for inducing vascular remodeling and improving reproductive outcome. Future studies are needed to determine whether beneficial effects would be evident in animal models of preeclampsia or in women predisposed to the development of preeclampsia.

Placental Protein 13 (PP13) - A Placental Immunoregulatory Galectin Protecting Pregnancy

Galectins are glycan-binding proteins that regulate innate and adaptive immune responses, and some confer maternal-fetal immune tolerance in eutherian mammals. A chromosome 19 cluster of galectins has emerged in anthropoid primates, species with deep placentation and long gestation. Three of the five human cluster galectins are solely expressed in the placenta, where they may confer additional immunoregulatory functions to enable deep placentation. One of these is galectin-13, also known as Placental Protein 13 (PP13). It has a "jelly-roll" fold, carbohydrate-recognition domain and sugar-binding preference resembling other mammalian galectins. PP13 is predominantly expressed by the syncytiotrophoblast and released from the placenta into the maternal circulation. Its ability to induce apoptosis of activated T cells in vitro, and to divert and kill T cells as well as macrophages in the maternal decidua in situ, suggests important immune functions. Indeed, mutations in the promoter and an exon of LGALS13 presumably leading to altered or non-functional protein expression are associated with a higher frequency of preeclampsia and other obstetrical syndromes, which involve immune dysregulation. Moreover, decreased placental expression of PP13 and its low concentrations in first trimester maternal sera are associated with elevated risk of preeclampsia. Indeed, PP13 turned to be a good early biomarker to assess maternal risk for the subsequent development of pregnancy complications caused by impaired placentation. Due to the ischemic placental stress in preterm preeclampsia, there is increased trophoblastic shedding of PP13 immunopositive microvesicles starting in the second trimester, which leads to high maternal blood PP13 concentrations. Our meta-analysis suggests that this phenomenon may enable the potential use of PP13 in directing patient management near to or at the time of delivery. Recent findings on the beneficial effects of PP13 on decreasing blood pressure due to vasodilatation in pregnant animals suggest its therapeutic potential in preeclampsia.

The role of the carbohydrate recognition domain of placental protein 13 (PP13) in pregnancy evaluated with recombinant PP13 and the DelT221 PP13 variant

INTRODUCTION

Placental protein 13 (PP13), a placenta specific protein, is reduced in the first trimester of pregnancy in women who subsequently develop preeclampsia. A naturally occurring PP13 deletion of thymidine at position 221 (DelT221 or truncated variant) is associated with increased frequency of severe preeclampsia. In this study we compared the full length (wildtype) PP13 and the truncated variant.

METHODS

Full length PP13 or its DelT221 variant were cloned, expressed and purified from E-Coli. Both variants were administrated into pregnant rats at day 8 of pregnancy for slow release (>5 days) through osmotic pumps and rat blood pressure was measured. Animals were sacrificed at day 15 or day 21 and their utero-placental vasculature was examined.

RESULTS

The DelT221 variant (11 kDA) lacked exon 4 and a part of exon 3, and is short of 2 amino acids involved in the carbohydrate (CRD) binding of the wildtype (18 kDA). Unlike the wildtype PP13, purification of DelT221 variant required special refolding. PP13 specific poly- clonal antibodies recognized both PP13 and DelT221 but PP13 specific monoclonal antibodies recognized only the wildtype, indicating the loss of major epitopes. Wildtype PP13 mRNA and its respective proteins were both lower in PE patients compared to normal pregnancies. The DelT221 mutant was not found in a large Caucasian cohort. Pregnant rats exposed to wildtype or DelT221 PP13 variants had significantly lower blood pressure compared to control. The wildtype but not the DelT221 mutant caused extensive vein expansion.

CONCLUSION

This study revealed the importance of PP13 in regulating blood pressure and expanding the utero-placental vasculature in pregnant rats. PP13 mutant lacking amino acids of the PP13 CRD domain fails to cause vein expansion but did reduce blood pressure. The study provides a basis for replenishing patients at risk for preeclampsia by the full length but not the truncated PP13.

Impact of changes to reimbursement of fixed combinations of inhaled corticosteroids and long-acting β₂ -agonists in obstructive lung diseases: a population-based, observational study

BACKGROUND

In 2010, the Icelandic government introduced a new cost-saving policy that limited reimbursement of fixed inhaled corticosteroid/long-acting β₂ -agonist (ICS/LABA) combinations.

METHODS

This population-based, retrospective, observational study assessed the effects of this policy change by linking specialist/primary care medical records with data from the Icelandic Pharmaceutical Database. The policy change took effect on 1 January 2010 (index date); data for the year preceding and following this date were analysed in 8241 patients with controlled/partly controlled asthma and/or chronic obstructive pulmonary disease (COPD) who had been dispensed an ICS/LABA during 2009. Oral corticosteroid (OCS) and short-acting β₂ -agonist (SABA) use, and healthcare visits, were assessed pre- and post-index.

RESULTS

The ICS/LABA reimbursement policy change led to 47.8% fewer fixed ICS/LABA combinations being dispensed during the post-index period among patients whose asthma and/or COPD was controlled/partly controlled during the pre-index period. Fewer ICS monocomponents were also dispensed. A total of 48.6% of patients were no longer receiving any respiratory medications after the policy change. This was associated with reduced disease control, as demonstrated by more healthcare visits (44.0%), and more OCS (76.3%) and SABA (51.2%) dispensations.

CONCLUSIONS

Overall, these findings demonstrate that changes in healthcare policy and medication reimbursement can directly impact medication use and, consequently, clinical outcomes and should, therefore, be made cautiously.

Localized rotational activation in the left atrium during human atrial fibrillation: relationship to complex fractionated atrial electrograms and low-voltage zones

BACKGROUND

In humans, the existence of rotors or reentrant sources maintaining atrial fibrillation (AF) and the underlying electroanatomic substrate has not been well defined.

OBJECTIVE

Our aim was to determine the prevalence of localized rotational activation (RotA) in the left atrium (LA) during human AF and whether complex fractionated atrial electrograms (CFAEs) or low-voltage areas colocalize with RotA sites.

METHODS

We prospectively studied 32 patients (mean age 57 ± 8 years; 88% with persistent AF) undergoing AF catheter ablation. Bipolar electrograms were recorded for 2.5 seconds during AF using a roving 20-pole circular catheter in the LA. RotA was defined as sequential temporal activation of bipoles around the circular catheter. Bipolar electrogram fractionation index and bipolar voltage were used to define CFAEs and low-voltage areas, respectively.

RESULTS

In 21 (66%) patients, 47 RotA sites were identified. Few (9%) lasted 2.5 seconds (cycle length 183 ± 6 ms), while the majority (91%) were nonsustained (duration 610 ± 288 ms; cycle length 149 ± 11 ms). RotA was most common in the pulmonary vein antrum (71%) and posterior LA (25%). CFAEs were recorded from 18% ± 12% of LA area, and most (92% ± 7%) were not associated with RotA sites. However, 85% of RotA sites contained CFAEs. Very low voltage (<0.1 mV) areas comprised 12% ± 10% of LA area and were present in 23% of RotA sites.

CONCLUSIONS

In patients with predominantly persistent AF, localized RotA is commonly present but tends to be transient (<1 second). Although most CFAEs do not colocalize with RotA sites, the high prevalence of CFAEs and very low voltages within RotA sites may indicate slow conduction in diseased myocardium necessary for their maintenance.

Potential negative consequences of non-consented switch of inhaled medications and devices in asthma patients

BACKGROUND

Asthma requires individually tailored and careful management to control and prevent symptoms and exacerbations. Selection of the most appropriate treatment is dependent on both the choice of drugs and inhaler device; however, financial pressures may result in patients being switched to alternative medications and devices in an attempt to reduce costs.

AIM

This review aimed to examine the published literature in order to ascertain whether switching a patient's asthma medications or device negatively impacts clinical and economic outcomes.

MATERIALS AND METHODS

A literature search of MEDLINE (2001-13 September 2011) was conducted to identify English-language articles focused on the direct impact of switching medications and inhaler devices and switching from fixed-dose combination to monocomponent therapy via separate inhalers in patients with asthma; the indirect impacts of switching were also assessed.

RESULTS

Evidence showed that non-consented switching of medications and inhalers in patients with asthma can be associated with a range of negative outcomes, at both individual and organisational levels. Factors that reduce adherence may lead to compromised symptom control resulting in increased healthcare resource utilisation and poorer patient quality of life.

DISCUSSION

The consequences of a non-consented switch should be weighed carefully against arguments supporting an inhaler switch without the patient's consent for non-medical/budgetary reasons, such as potential reductions in initial acquisition costs, which may be associated with subsequent additional healthcare needs.

CONCLUSION

Given the increasing pressure for reduced costs and efficient allocation of limited healthcare resources, an additional investment in ensuring high medication adherence may lead to greater savings due to a potentially decreased demand for healthcare services. In contrast, savings achieved in acquisition costs may result in a greater net loss due to increased healthcare consumption caused by decreased asthma control.

Placental protein 13 (PP13): a new biological target shifting individualized risk assessment to personalized drug design combating pre-eclampsia

BACKGROUND

Pre-eclampsia affects 2-7% of all pregnant women and is a major cause of maternal and fetal morbidity and mortality. The etiology of pre-eclampsia is still unknown but it is well documented that impaired placentation is a major contributor to its development. One of the placenta-specific proteins is placental protein 13 (PP13). Lower first trimester levels of maternal serum PP13 and its encoding placental mRNA are associated with the development of both early and late-onset severe pre-eclampsia. In cases where this protein is mutated, the frequency of pre-eclampsia is higher.

METHODS

19 out of 68 studies on PP13, published between January 2006 and September 2012, were used to evaluate the value of maternal blood PP13 as a marker of pre-eclampsia.

RESULTS

A meta-analysis presented in this review shows that low serum levels of PP13 in the first trimester of pregnancy can predict the development of pre-eclampsia later in pregnancy. Although some functions of this protein have been assessed in in vitro experiments, the in vivo functions of PP13 are still unknown, especially when circulating in the maternal bloodstream. A recent pilot study has shown that in gravid rats PP13 causes significant vasodilatation, reduced blood pressure and increased maternal uterine artery remodeling.

CONCLUSION

Reviewing these effects of PP13, the authors propose the use of PP13 as a new drug candidate. Replenishing PP13 in those women with low serum levels early in pregnancy may help prepare their vasculature for pregnancy. This novel pharmacological approach to combat pre-eclampsia is presented as a new direction to transfer from individualized risk to personalized prevention.

Effects of placental protein 13 on the cardiovascular system in gravid and non-gravid rodents

OBJECTIVES

Here, we performed a pathophysiological examination of the vascular function of rodent in the presence of placental protein 13 (PP13) and its implication to regulate the development of preeclampsia.

METHODS

Single i.v. injection and prolonged in vivo exposure to PP13 via osmotic pumps were performed in gravid and non-gravid rats to examine the influence of PP13 on blood pressure and heart rate in animals. The effect of PP13 was also examined in isolated uterine and mesenteric arteries, along with the examination of placental blood supply.

RESULTS

Human PP13 has a major impact on the maternal cardiovascular system of rodents by reducing blood pressure, either at single or prolonged exposure, and causing significant vasodilatation in isolated arteries. Prolonged exposure was followed by increased elaboration and angiogenesis of the uteroplacental arteries supplying the placenta.

CONCLUSION

This is the first study describing effects of PP13 on vasodilatation and uterine artery remodeling. The results imply that PP13 may have a physiological role in improving uteroplacental blood flow. The findings of this study make it tempting to speculate that keeping PP13 levels within a certain 'therapeutic window' during pregnancy may facilitate proper adaptation of the maternal vasculature to pregnancy.

p-Chloroamphetamine-induced rat ejaculation is not associated with the preoptic nucleus or medial nucleus amygdala

Aim:  In the rat, intraperitoneal injection of p-chloroamphetamine (PCA), which releases central 5-hydroxytryptamine (5-HT) from serotonergic nerve terminals, induces ejaculation, even in the absence of an estrus female or female-related smell information. It is well known that the medial preoptic nucleus (MPN) and the medial nucleus amygdala (MEA) play a major role in the control of male sexual behavior in mammals. We examined whether or not neuronal activity of the MPN and/or the MEA was associated with PCA-induced ejaculation. Methods:  Using c-Fos immunohistochemistry, we demonstrated a difference in the neural activities of the MPN and the MEA for ejaculation during copulation with an estrus female and ejaculation by PCA injection. Results:  Increased numbers of c-Fos-immunoreactive (c-Fos-IR) cells were found in the MPN and the MEA in the brains of the mating animals, whereas in the brains of the animals undergoing PCA-induced ejaculation there was no increase in the number of c-Fos-IR cells in the MPN and a small increase in the MEA. Conclusion:  Based on these results, ejaculation induced by PCA is not associated with the MPN. Moreover, the MEA is not the main act for this ejaculation. (Reprod Med Biol 2008; 7: 37-43).

Immunization prevents DDT buildup in mouse tissues

DDT is used for pest control, causing health and environmental hazards in some parts of the world. The goal of this study was to assess whether immunization against a toxic compound could reduce the toxicant uptake of an organism, specifically to develop a DDT immunization that promotes the production of specific antibodies and assess whether it reduces DDT levels in the bodies of mice that are exposed to DDT by intake. BALB/c mice were immunized with DDT-keyhole limpet hemocyanine (DDT-KLH) conjugate (n=10) or unconjugated KLH (n=10), which was used as a control. After the immunization specific DDT antibodies in the mouse serum were determined by ELISA and then the mice were fed chow containing 40 mg/kg of DDT for 45 days. Finally, the concentration of DDT and its metabolites, DDE and DDD, in various tissues was measured by gas chromatography. Specific DDT antibody levels were significantly higher in the DDT immunized group than in the control group. DDT, DDE and DDD levels in adipose tissue, blood, brain and spleen were significantly reduced in the DDT immunized animals relative to control animals. However, DDT and DDD levels were higher in the liver compared to the control group. The findings indicate that the DDT immunization reduces the total uptake of DDT in animal tissues, which is reflected by the lower levels in adipose tissue, blood, brain and spleen. The elevated levels in liver suggest that DDT-antibody complexes in mouse serum are delivered to the liver.

Effects of complete heart block on myocardial function, morphology, and energy metabolism in the rat

AIMS

Severe sustained bradycardia may cause acute and possibly chronic congestive heart failure (CHF). The aim of this study was to investigate acute and chronic effects of complete heart block (CHB) on cardiac function, morphology, and creatine (Cr) metabolism.

METHODS AND RESULTS

CHB was induced in male Sprague-Dawley rats (approximately 250 g, n = 11) by means of electrocautery applied to the region of AV node and were compared with controls (n = 15). The rats were investigated at 1, 3, and 12 weeks after CHB induction with transthoracic echocardiography. Invasive haemodynamic assessment of left and right ventricular pressures was performed at 12 weeks. After the sacrifice, the hearts were freeze-clamped for analysis of myocardial Cr, and high energy phosphometabolites. The efficacy of operative procedure was 54%. The peri-operative mortality rate was 20%. Heart rate (HR) decreased by approximately 50% (P < 0.01) while stroke volume (SV) increased 2.5 times (P < 0.01) in the CHB rats. Cardiac index remained unchanged. The rats with CHB grew normally and were in no apparent distress. Filling pressures in left and right ventricles were normal. The CHB rats developed marked cardiomegaly with biventricular dilatation and eccentric left ventricular hypertrophy (P < 0.01). There was no change in the myocardial content of Cr and high energy phosphometabolites.

CONCLUSION

Rats with CHB are compensating for reduction in HR with increased SV without haemodynamic and biochemical characteristics of CHF. This model may be useful to study the effects of CHB and bradycardia on myocardial structure, function, electrophysiology, and metabolism as well as for studies of cell therapy for reparation of AV conductance.

Mucosal Tolerance to KLH Reduces BSA-Induced Arthritis in Rats—An Indication of Bystander Suppression

Mucosal tolerance has been shown to reduce disease severity in animal models mimicking human autoimmune diseases. The objective of this study was to examine whether mucosal tolerance against keyhole limpet haemocyanin (KLH) could be used to reduce bovine serum albumin (BSA)-induced arthritis in rats and whether anti-inflammatory drugs or passive cigarette smoke affected tolerance induction. Arthritis was induced by immunizing rats with BSA and then injecting BSA into one knee and saline into the other knee for comparison. Prior to BSA immunization, the rats were treated intranasally with KLH or saline and KLH then injected in the knee joints at the time of BSA injection, or the rats were treated with or without anti-inflammatory drugs or subjected to cigarette smoke prior to and during intranasal treatment with BSA. The rats that received intranasal treatment with KLH had a significantly less inflammation in their left knee joint compared to rats that received intranasal saline treatment. Beclamethasone increased the tolerance effect of BSA, whereas passive cigarette smoke abrogated the mucosal tolerance. This data suggests that bystander suppression can be used to treat arthritis and other autoimmune diseases, even when the autoantigen is not known.

Induction of protective and specific antibodies against cocaine by intranasal immunisation using a glyceride adjuvant

The goal of this study was to investigate an intranasal cocaine vaccine containing the mucosal adjuvant macrogol-6-glycerol capylocaprate (RhinoVax). Cocaine-KLH conjugate was prepared and administered in two formulations. Ten mice were immunised intranasally using RhinoVax as adjuvant and ten subcutaneously using aluminium hydroxide as an adjuvant. A negative control group (n=10) received unconjugated KLH with RhinoVax intranasally. Specific cocaine antibodies in serum were measured following primary and booster immunisation. Relative antibody responses in serum indicated that the immunisation was successful. Animals were then challenged with cocaine either intranasally or intraperitoneally with subsequent measurement of drug distribution into the serum, brain and olfactory bulb. The cocaine-immunised groups revealed significantly lower cocaine levels in the brain compared to the negative control group. The inhibition of cocaine distribution to the brain in the intranasal immunised group was comparable to that of the subcutaneous immunised group. This was unexpected because the cocaine specific antibody levels in serum were fivefold lower in the intranasal immunised group. However, the presence of mucosal cocaine specific antibodies after intranasal immunisation could play an important role in hindering direct access of cocaine into the brain via the olfactory bulb.

[Attitude of the Icelandic population towards performing cardiopulmonary resuscitation on strangers in the pre-hospital setting.]

OBJECTIVE

Initiation of bystander cardiopulmonary resuscitation (CPR) is directly linked to the outcome of cardiac arrest in the community. Recent reports have indicated a reluctance among witnesses to perform CPR on strangers especially mouth to mouth ventilation. The status of this in Iceland is unknown. The objective of this study was to assess the attitude of Icelanders towards bystander CPR.

MATERIAL AND METHODS

A telephone survey was conducted on 1200 randomly selected Icelanders, aged 16-75 years, with regard to their attitude towards pre-hospital CPR on strangers. A total of 804 (70.1%) chose to participate.

RESULTS

A large number had received some kind of training in CPR (73%), wheras only 6% had actually participated in CPR. In accordance, 50% thought they would be able to perform chest compressions adequately and 55% mouth to mouth ventilation. A total of 491 (65%) would likely volunteer to perform chest compressions on a stranger, while 178 (24%) would not and 84 (11%) were undecided. Similarly, 473 (64%) would likely volunteer to perform mouth to mouth ventilation on a stranger. One hundred seventy seven (24%) would not and 93 (12%) were unsure. An overwhelming majority, 620 (81%) said it would not make any difference regarding their participation in CPR if the procedure was simplified and included only chest compressions but not mouth to mouth ventilation.

CONCLUSIONS

Icelanders have a very positive attitude towards bystander CPR, over two thirds have had some kind of CPR instruction and a large majority has no aversion towards performing mouth to mouth ventilation on strangers. These results are in contrast to similar data from the United States.

Serum amyloid P component inhibits influenza A virus infections: in vitro and in vivo studies

Serum amyloid P component (SAP) binds in vitro Ca(2+)-dependently to several ligands including oligosaccharides with terminal mannose and galactose. We have earlier reported that SAP binds to human influenza A virus strains, inhibiting hemagglutinin (HA) activity and virus infectivity in vitro. These studies were extended to comprise five mouse-adapted influenza A strains, two swine influenza A strains, a mink influenza A virus, a ferret influenza A reassortant virus, a influenza B virus and a parainfluenza 3 virus. The HA activity of all these viruses was inhibited by SAP. Western blotting showed that SAP bound to HA trimers, monomers and HA1 and HA2 subunits of influenza A virus. Binding studies indicated that galactose, mannose and fucose moieties contributed to the SAP reacting site(s). Intranasal administration of human SAP to mice induced no demonstrable toxic reactions, and circulating antibodies against SAP were not detected. Preincubation of virus (A/Japan/57) with SAP prevented primary infection of mice and development of antiviral antibodies. After a single intranasal administration of SAP (40 microg) 1 h before primary infection with virus (2LD(50)), nine out of 10 mice survived on day 10 and these mice approached normal body weight, whereas control mice (one out of five surviving on day 10) died. The data provide evidence of the potential of intranasally administered SAP for prophylactic treatment of influenza A virus infections in humans.

Intranasal absorption of buprenorphine--in vivo bioavailability study in sheep

The bioavailability of buprenorphine, HCl (BPP) in sheep after nasal administration of two formulations has been studied. 0.9 mg BPP in 150 microl was administered nasally and compared to 0.6 mg i.v. The test solutions were formulated with 30% polyethylene glycol 300 (PEG 300) and 5% dextrose, respectively. The bioavailability for PEG 300 was 70% (S.D.+/-27%, n=6), whereas the bioavailability for 5% dextrose was 89% (S.D.+/-23%, n=6). A two-compartment model with initial and terminal serum half-lives of 10 and 23 min, respectively, may describe the pharmacokinetics. The rate of absorption for both nasal formulations was very fast (t(max)=10 min). The C(max) was 37 ng/ml (S.D.+/-17) and 48 (S.D.+/-10) for PEG 300 and dextrose, respectively. No significant difference was found between the two formulations, but PEG 300 has advantages in relation to freezing point depression and solubility, which may be considered if further studies are going to be initiated. The high nasal bioavailability and short time to maximal plasma concentration suggests that it is possible to make a clinically relevant nasal formulation of BPP for the treatment of pain.

Intranasal immunization with pneumococcal polysaccharide conjugate vaccines protects mice against invasive pneumococcal infections

Host defenses against Streptococcus pneumoniae depend largely on opsonophagocytosis mediated by antibodies and complement. Since pneumococcus is a respiratory pathogen, mucosal immune responses may play a significant role in the defense against pneumococcal infections. Thus, mucosal vaccination may be an alternative approach to current immunization strategies, but effective adjuvants are required. Protein antigens induce significant mucosal immunoglobulin A (IgA) and systemic IgG responses when administered intranasally (i. n.) with the glyceride-polysorbate based adjuvant RhinoVax (RV) both in experimental animals and humans. The immunogenicity and efficacy of pneumococcal polysaccharide conjugate vaccines (PNC) of serotypes 1 and 3 was studied in mice after i.n. immunization with RV. Antibodies were measured in serum (IgM, IgG, and IgA) and saliva (IgA) and compared to antibody titers induced by parenteral immunization. The PNCs induced significant systemic IgG and IgA antibodies after i.n. immunization only when given with RV and, for serotype 1, serum IgG titers were comparable to titers induced by subcutaneous immunization. In addition, i.n. immunization with PNC-1 in RV elicited detectable mucosal IgA. These results demonstrate that RV is a potent mucosal adjuvant for polysaccharides conjugated to proteins. A majority of the PNC-1-immunized mice were protected against both bacteremia and pneumonia after i.n. challenge with a lethal dose of serotype 1 pneumococci, and protection correlated significantly with the serum IgG titers. Similarly, the survival of mice immunized i.n. with PNC-3 in RV was significantly prolonged. These results indicate that mucosal vaccination with PNC and adjuvants may be an alternative strategy for prevention against pneumococcal infections.

Single- and repeated-dose local toxicity in the nasal cavity of rabbits after intranasal administration of different glycols for formulations containing benzodiazepines

To furnish a systemic effect after intranasal administration, a formulation must contain the therapeutic dose in no more than 150 L, the maximum volume that can be applied as a single administration in one nostril in man. The objectives of these studies were to examine the local toxicity of formulations containing benzodiazepines and to document the effects to support clinical trials in man. After stability, pharmacological and pharmacokinetic studies of several benzodiazepine formulations, we studied nasal toxicity after single and repeated administration to rabbits of poly(ethylene glycol) 200, tetra(ethylene glycol), glycofurolum and mixtures of these vehicles both with and without benzodiazepines. Single-dose studies with examinations 5 or 10min after application were undertaken with poly(ethylene glycol), tetra(ethylene glycol), glycofurolum and tetra(ethylene glycol)-glycofurolum in the ratio 95:5; the reactions were similar to that after physiological saline. A 14-day repeated-dose study was conducted with diazepam, lorazepam and flunitrazepam formulations in poly(ethylene glycol), and flunitrazepam in poly(ethylene glycol)-glycofurolum in the ratio 70:30; the two vehicles without any benzodiazepine were also examined. Microscopic study revealed mild changes only in the treated groups. A final four-week study was conducted with repeated administration of clonazepam formulated in tetra(ethylene glycol)-glycofurolum in the ratio 95:5; microscopy revealed mild changes after three 150-microL doses daily, but no abnormalities after one or three 100-microL doses daily. It was concluded that these three solvents individually or as mixtures resulted in only mild local toxicity and might be acceptable as vehicles in nasal preparations of benzodiazepines and other non-irritating drugs for short-term use in man.

Intranasal administration of diazepam aiming at the treatment of acute seizures: clinical trials in healthy volunteers

Intranasal administration of diazepam may be a practical alternative to the conventional acute medication of seizures, such as status epilepticus. Nine healthy students participated in an open crossover study on intranasal versus intravenous administration of diazepam (2 mg). Blood samples were collected, pharmacodynamic tests were performed, and the volunteers filled out questionnaire. Peak concentration was achieved after 18+/-11 min and the bioavailability was 50.4+/-23.3%. A pharmacodynamic effect was observed after about 5 min, but the dose, even for i.v. administration, was too low to generate a strong measurable effect. The results indicate that intranasally administered diazepam may be an effective alternative to i.v. administration in relief of seizures, e.g. in an acute situation when a physician or nurse is not available on location.

Selective augmentation of antibodies in various mucosal regions, after intranasal immunization with diphtheria in mice

The kinetics of antibody responses were analyzed in various mucosal membranes as well as in the blood and the spleen after intranasal vaccination of mice with diphtheria toxoid. The results show a selective increase in antibody response in the respiratory area and the vagina followed by the gastrointestinal tract, but not in the spleen. IgG and IgM showed an increase 7 days after revaccination, followed by a rapid decline. However, IgA peaked 3 days after revaccination and did not decline throughout the study.

Intranasal vaccination: pharmaceutical evaluation of the vaccine delivery system and immunokinetic characteristics of the immune responses

The purpose of this study was to analyze the effect of some pharmaceutical excipients when used for mucosal vaccine formulations and to characterize the achieved immune response. After conducting various pharmaceutical evaluations of the formulations, immunokinetic studies were performed in mice, guinea pigs, and rabbits. The kinetics and the characteristics (antibody isotypes, etc.) of the immune response were studied, as well as the induced level of toxin neutralizing IgG antibodies, which are usually used as the only measures of the potency of vaccines. Results in mice show that intranasal vaccination results in a potent and rapid immune response, similar to that seen after subcutaneous immunization. In guinea pigs and rabbits, however, the subcutaneous immunization produced significantly stronger response than did intranasal vaccination. The most promising excipients were found to be either Polysorbate 20 or Cremophor EL in an aqueous mixture together with caprylic/capric glyceride. The results indicate that nontoxic and pharmaceutically acceptable excipients can be used for mucosal vaccination, providing an interesting alternative to parenteral vaccination.

Pharmacokinetic and pharmacodynamic response after intranasal administration of diazepam to rabbits

Nasal application of drugs might be an alternative to intravenous administration in acute situations such as epileptic or fever seizures. In the search for a nasal formulation leading to a peak plasma concentration of diazepam at a tmax < or = 5 min bioavailability in rabbits has been studied after intranasal administration of the drug in ten vehicles of different polarity. The animals were dosed with 3 mg diazepam, dissolved in 100 microL vehicle, the solution being administered into both nostrils. The bioavailability, measured during the first 30 min, because periods after this are not relevant for acute treatment, was found to be between 49 and 62% for the four most promising vehicles, pure glycofurol 75, tetraethyleneglycol, poly(ethylene glycol) 200 and 30% glycofurol in tetraethyleneglycol. The tmax for these vehicles was achieved after 5 min, and they induced a very rapid pharmacodynamic response after 1.5 to 3.5 min. The bioavailability was reduced when more polar liquids such as ethanol and tween 20, or lipid oils, e.g. vegetable oil and miglyol 840 were added to the glycofurol. There was a good correlation between tmax and the induction of pharmacodynamic response. These results suggest that nasal application of diazepam in a water-free low-molecular-weight glycol might be of clinical importance as an alternative to intravenous injection, especially in acute situations.

Intranasal booster vaccination against diphtheria and tetanus in man

The booster responses of three different formulations of intranasal (i.n.) diphtheria-tetanus (D-T) vaccines were determined in military recruits and compared with a conventional subcutaneous D-T vaccine. The vaccines for mucosal delivery were sprayed into one nostril and contained D and T toxoids in an enhancer mixture of polysorbate and caprylic/capric glycerides. All of the vaccines gave rise mainly to a systemic IgG response. Among 51 persons with anti-D antibody concentrations in serum below a protective level of 0.01 international units (IU ml-1) before vaccination, all except two attained protective antibody concentrations 4 weeks after vaccination. The median increase in anti-D antibody concentration was 113-fold with the most efficient i.n. formulation. The median increase in anti-T antibody level was 2.4-fold, however, the pre-vaccination levels for this antigen were very high. Within the examined levels, the booster response depended mainly on the dose of the antigen in the vaccine rather than on the concentration of the vehicle mixture. Compared with the parenteral D-T vaccine containing aluminium hydroxide as an adjuvant, all of the tested i.n. formulations showed somewhat lower immunogenicity in man as well as in pre-clinical guinea-pig studies. Among 215 persons immunized i.n., 61% preferred this route of administration rather than a parenteral injection, although the formulations were all associated with varying local symptoms, frequently stinging and pronounced, nasal secretion.

Evaluation of local toxicity after repeated intranasal vaccination of guinea-pigs

In intranasal vaccination it is important that the adjuvant does not have any toxic effect on the sensitive nasal mucosa. In this study a histological and clinical evaluation of the effects of two different adjuvants in a vaccine containing detoxified diphtheria (DT) and tetanus toxoid (TT) in guinea pigs was done. The guinea pigs were divided in four groups and treated daily for 14 days with different formulations. Group I with saline, Groups 2 and 3 with the vaccines in a non-ionic surfactant formulation containing glycerides and Group 4 with tetraethyleneglycol formulation containing glycofurol. The guinea pigs in Groups 1, 2 and 4 were sacrificed on day 15 and Group 3, 1 week later and the tissues processed for histological examination. The animals remained healthy during the treatment and minor clinical signs, such as nose-blowing, decreased with time. The histological appearance, including the development of lymphoid tissue, was comparable in all groups. A specific toxic effect on the nasal mucosa by the different vaccine and adjuvant formulations was not observed.

Intranasal administration of diphtheria toxoid. Selecting antibody isotypes using formulations having various lipophilic characteristics

Non-ionic excipients, having different lipophilicity, were compared for their selection of immunological response in different organs and biological fluids. In order to express the lipophilicity of the formulation, the balance between the size and strength of the hydrophilic and lipophilic groups was used, called the hydrophile-lipophile balance (HLB) value. Mice were immunized and boosted intranasally with diphtheria toxoid, and samples were taken from the blood, spleen, nasal wash, lungs, saliva, stomach, duodenum, jejunum and the skin. In general, formulations which were highly hydrophilic and highly lipophilic were not able to augment the immunological response markedly (except for IgA). Formulations having intermediate HLB values, e.g. around 9.0, stimulated both IgG1 and IgG2a production, where the HLB = 5.5 formulation seemed to stimulate mainly IgG2b and IgG3 antibody production. On the other hand, comparing the IgA concentration in various samples with respective IgG level, increasing HLB value seems to augment the production of mainly IgA antibodies. The results indicate that the antibody isotypes may be controlled, using variations in the hydrophile-lipophile balance value.

Stimulation of the transepithelial flux of influenza HA vaccine by cholera toxin B subunit

Secretory antibodies in mucosal surfaces are known to play an essential role in protection against various infectious diseases. To enhance the production of such antibodies, influenza HA vaccine was inoculated intranasally into rabbits, together with cholera toxin B subunit (CTB) which is known to augment antibody response to an unrelated antigen. This combination resulted in high levels of serum IgG antibody responses against HA and CTB molecules, 3-4 weeks after inoculation, compared with the inoculation of HA vaccine alone. The adjuvant mechanism for CTB was studied by using Ussing chambers, in which nasal mucosa from rabbits were mounted. CTB was found to enhance the transepithelial flux of HA vaccine, from the mucosal side (lumen) into the serosal side (lamina propria), indicating that the permeability of the membrane was changed by CTB. Moreover, to achieve effective flux of HA vaccines, some interactions between the vaccine and CTB across the membrane were found, which may effect the effectiveness of the vaccine formulation. The results suggest that one of the mechanisms by which CTB enhances the production of mucosal antibody response is to enhance the transepithelial influx of vaccine into the nasal mucosa, where the cells involved in the antibody production are located. CTB may be used as a potent adjuvant to induce antibody response, by nasal vaccination, against pathogens impinging on mucosal surfaces.