Sublingual Diffusion of Epinephrine Microcrystals from Rapidly Disintegrating Tablets for the Potential First-Aid Treatment of Anaphylaxis: In Vitro and Ex Vivo Study

Formulation and optimization of ivermectin nanocrystals for enhanced topical delivery

The increasing resistance to antiparasitic drugs and limited availability of new agents highlight the need to improve the efficacy of existing treatments. Ivermectin (IVM) is commonly used for parasite treatment in humans and animals, however its efficacy is not optimal and the emergence of IVM-resistant parasites presents a challenge. In this context, the physico-chemical characteristics of IVM were modified by nanocrystallization to improve its equilibrium water-solubility and skin penetration, potentially improving its therapeutic effectiveness when applied topically. IVM-nanocrystals (IVM-NC) were prepared using microfluidization technique. The impact of several process/formulation variables on IVM-NC characteristics were studied using D-optimal statistical design. The optimized formulation was further lyophilized and evaluated using several in vitro and ex vivo tests. The optimal IVM-NC produced monodisperse particles with average diameter of 186 nm and polydispersity index of 0.4. In vitro results showed an impressive 730-fold increase in the equilibrium solubility and substantial 24-fold increase in dissolution rate. Ex vivo permeation study using pig's ear skin demonstrated 3-fold increase in dermal deposition of IVM-NC. Additionally, lyophilized IVM-NC was integrated into topical cream, and the resulting drug release profile was superior compared to that of the marketed product. Overall, IVM-NC presents a promising approach to improving the effectiveness of topically applied IVM in treating local parasitic infections.

Optimization, Characterization and In Vivo Evaluation of Mupirocin Nanocrystals for Topical Administration

Treatment of infectious skin conditions resulting from wounds and burns with topical antibiotics is challenging, particularly those caused by methicillin-resistant Staphylococcus aureus bacteria (MRSA). This is due to the formation of bacterial biofilms characterized by antimicrobial resistance. Mupirocin (MP), a widely used topical antibiotic, is active against gram-positive bacteria including MRSA. However, MP suffers from sub-optimal therapeutic efficacy due to its poor water-solubility and the significant rise in MP-resistant S. aureus. In this study, the physico-chemical characteristics of MP were modified through nanocrystallization to improve its therapeutic efficacy for the treatment of skin infections. Mupirocin-nanocrystals (MP-NC) were prepared using a nanoprecipitation technique and optimized using a D-optimal response surface design. The optimization of MP-NC produced ultra-small monodisperse spherical particles with a mean diameter of 70 nm and a polydispersity index of 0.2. The design resulted in two optimal MP-NC formulations that were evaluated by performing series of in vitro, ex vivo, microbiological, and in vivo studies. In-vitro results showed a 10-fold increase in the saturation solubility and a 9-fold increase in the dissolution rate of MP-NC. Ex vivo permeation studies, using pig ears skin, showed a 2-fold increase in the dermal deposition of MP-NC with the highest drug deposition occurring at 500-µm skin depth. Moreover, the optimal MP-NC formulations were lyophilized and incorporated into a 2% w/w cream. Microbiological studies revealed a 16-fold decrease in the minimum inhibitory concentration and the minimum bactericidal concentration of MP-NC. In vivo studies, using a rat excision burn wound model, demonstrated rapid and complete healing of infected burn wounds in rats treated with MP-NC cream in comparison to marketed Avoban ointment. Our results suggest that nanocrystallization of MP may provide an avenue through which higher levels of a topically applied MP can be permeated into the skin to reach relevant infectious areas and exert potential local antibacterial effects.

Assessment of epinephrine sublingual stability and permeability pathways to enhance its permeability for the treatment of anaphylaxis

Prompt epinephrine (Epi) injection using auto-injectors is the initial life-saving out-of-hospital treatment for anaphylaxis. However, patients and healthcare providers are eagerly awaiting a more convenient alternative dosage form that would overcome auto-injectors drawbacks. Previously, we extensively evaluated multiple alternative fast-disintegrating sublingual Epi tablet (FDSTs) formulations. However, the sublingual stability of Epi and effect of modifying the sublingual microenvironment pH on its stability and transport pathways were not yet fully investigated. Results depicted that Epi remained sufficiently stable at various pHs in human saliva and porcine sublingual tissue's extract. Epi permeability (EP) through excised porcine sublingual membrane was greatest at pH 8.0 (p < 0.05), 11-fold higher than the negative control (Epi at pH 6.8). Sodium carbonate (Na Carb) 0.75% was the most efficient buffer to modify Epi solution pH to 8.0. Both sodium dodecyl sulfate (SDS) 0.075% and palmitoyl-DL-carnitine chloride (PCC) 1.2% increased paracellular EP 10-fold and 3-fold, respectively; however, both demonstrated a delayed enhancement (>5 min). Meanwhile, Na Carb and SDS combination increased EP 23-fold without a delay. It is evident that pH-modifiers or their SDS combination showed promising potential to enhance Epi sublingual permeability and further reduce the required Epi dose using FDSTs as a feasible alternative to Epi auto-injectors.

Modulation of the sublingual microenvironment and pH-dependent transport pathways to enhance atropine sulfate permeability for the treatment of organophosphates poisoning

Atropine sulfate (AS) auto-injectors are the only approved antidote for out-of-hospital emergency treatment of organophosphates (OP) toxicity. However, they are only available for military use and require the administration of multiple auto-injectors. Therefore, an alternative, patient-friendly and more affordable fast-disintegrating sublingual tablets (FDSTs) of AS were previously developed. In this article, the effect of modifying the microenvironment's pH and/or using penetration enhancers on AS sublingual transport pathways were evaluated in an attempt to further enhance AS sublingual permeability. Ten different AS FDST formulations with or without the incorporation of alkalizer and various penetration enhancers were manufactured and characterized. AS permeability was investigated through excised porcine sublingual membrane using Franz cells. Results showed that the incorporation of either a transcellular enhancer or alkalizer achieved a significantly higher AS permeability enhancement (twofold). Combining sodium bicarbonate (Na Bicarb) 2% as alkalizer with sodium dodecyl sulfate (SDS) 1% as a transcellular enhancer resulted in the greatest synergistic enhancement in AS sublingual permeability (up to twelvefold). In conclusion, the modified AS FDST developed in this work has the potential to improve the pharmacokinetic parameters of AS following sublingual administration for the first-aid treatment of OP toxicity in future animal bioequivalency studies.

World allergy organization anaphylaxis guidance 2020

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions. The occurrence of anaphylaxis has increased in recent years, and subsequently, there is a need to continue disseminating knowledge on the diagnosis and management, so every healthcare professional is prepared to deal with such emergencies. The rationale of this updated position document is the need to keep guidance aligned with the current state of the art of knowledge in anaphylaxis management. The World Allergy Organization (WAO) anaphylaxis guidelines were published in 2011, and the current guidance adopts their major indications, incorporating some novel changes. Intramuscular epinephrine (adrenaline) continues to be the first-line treatment for anaphylaxis. Nevertheless, its use remains suboptimal. After an anaphylaxis occurrence, patients should be referred to a specialist to assess the potential cause and to be educated on prevention of recurrences and self-management. The limited availability of epinephrine auto-injectors remains a major problem in many countries, as well as their affordability for some patients.

Effect of Fast-Disintegrating Tablets' Characteristics on the Sublingual Permeability of Atropine Sulfate for the Potential Treatment of Organophosphates Toxicity

Atropine sulfate (AS) fast-disintegrating sublingual tablets (FDSTs) were tested for AS sublingual permeation's feasibility as a potential alternative dosage form to treat organophosphates (OP) toxicity. More than 12,000 OP pesticide toxicity cases were reported in the USA from 2011 to 2014. AS is the recommended antidote for OP toxicity; however, it is only available as an ATROPEN® auto-injector, an IM injection, for self-administration, which is associated with several drawbacks and limitations. Six AS FDST batches were formulated and characterized. Two tablet sizes, group A weighing 150 mg and group B weighing 50 mg, were formulated with three different AS doses: 2 mg (A1 and B1), 4 mg (A2 and B2), and 8 mg (A3 and B3). AS in vitro diffusion and sublingual permeation were investigated in Franz cells using a cellulose membrane and an excised porcine sublingual membrane. The effect of AS load and tablet size on sublingual permeation was also evaluated. All batches passed quality control tests. AS FDSTs' size and AS load had a significant effect on tablet disintegration time and drug dissolution, which significantly impacted AS concentration gradient across the diffusional membrane. Group B FDSTs (smaller tablets) resulted in a significantly higher initial permeation (JAUC_0-15) compared to group A FDSTs. Also, the cumulative AS (JAUC_0-90) and AS influx (J) increased linearly with increasing AS dose. These AS FDSTs have the potential to be explored in vivo to determine the required bioequivalent sublingual AS dose as an alternative dosage form for the treatment of OP toxicity.

In Vivo Evaluation of Taste-Masked Fast-Disintegrating Sublingual Tablets of Epinephrine Microcrystals

In community settings, IM injection of 0.3 mg epinephrine (Epi) using an auto-injector is the drug of choice for treatment of anaphylaxis. Previously, a taste-masking (TM) formulation of fast-disintegrating sublingual tablets (FDSTs) was developed in our lab. Also, Epi was micronized (Epi-MC) successfully and reduced the previously achieved bioequivalent sublingual Epi dose to 0.3 mg IM injection by half using non-taste-masked fast-disintegrating sublingual tablets (TM-FDSTs). Our objective for this study was to evaluate the sublingual absorption of Epi-MC using TM-FDST. These sublingual Epi tablets have potential for out-of-hospital treatment of anaphylaxis and are suitable for human studies. TM-FDSTs containing Epi-MC were manufactured by direct compression. The rate and extent of Epi absorption from our developed 20 mg Epi-MC-TM-FDSTs (n = 5) were evaluated in rabbits and compared to the previous result from 20 mg Epi-MC in non-TM-FDSTs and EpiPen® auto-injector. Blood samples were collected over 1 h, and Epi concentrations were measured using HPLC with electrochemical detection. Mean ± SEM AUC0-1 h and Cmax from 20 mg Epi-MC-TM-FDSTs (733 ± 78 ng/ml/min and 30 ± 8 ng/ml) and 20 mg Epi-MC-non-TM-FDSTs (942 ± 109 ng/ml/min and 38 ± 4 ng/ml) were not significantly different (p > 0.05) from each other or from EpiPen® (592 ± 50 ng/ml/min and 28 ± 3 ng/ml) but were significantly higher (p < 0.05) than endogenous Epi after placebo FDSTs (220 ± 32 ng/ml/min and 8 ± 1 ng/ml). Mean ± SD Tmax was not significantly different (p > 0.05) among all formulations. Epi-MC-TM-FDSTs formulation improved Epi absorption twofold and reduced the required bioequivalent dose by 50%, similar to results obtained using non-TM-FDSTs. The incorporation of TM excipients did not interfere with the absorption of Epi-MC.

Epinephrine in Anaphylaxis: Preclinical Study of Pharmacokinetics after Sublingual Administration of Taste-Masked Tablets for Potential Pediatric Use

Epinephrine is a life-saving treatment in anaphylaxis. In community settings, a first-aid dose of epinephrine is injected from an auto-injector (EAI). Needle phobia highly contributes to EAI underuse, leading to fatalities—especially in children. A novel rapidly-disintegrating sublingual tablet (RDST) of epinephrine was developed in our laboratory as a potential alternative dosage form. The aim of this study was to evaluate the sublingual bioavailability of epinephrine 30 mg as a potential pediatric dose incorporated in our novel taste-masked RDST in comparison with intramuscular (IM) epinephrine 0.15 mg from EAI, the recommended and only available dosage form for children in community settings. We studied the rate and extent of epinephrine absorption in our validated rabbit model (n = 5) using a cross-over design. The positive control was IM epinephrine 0.15 mg from an EpiPen Jr^®. The negative control was a placebo RDST. Tablets were placed under the tongue for 2 min. Blood samples were collected at frequent intervals and epinephrine concentrations were measured using HPLC with electrochemical detection. The mean ± SEM maximum plasma concentration (C_max) of 16.7 ± 1.9 ng/mL at peak time (T_max) of 21 min after sublingual epinephrine 30 mg did not differ significantly (p > 0.05) from the C_max of 18.8 ± 1.9 ng/mL at a T_max of 36 min after IM epinephrine 0.15 mg. The C_max of both doses was significantly higher than the C_max of 7.5 ± 1.7 ng/mL of endogenous epinephrine after placebo. These taste-masked RDSTs containing a 30 mg dose of epinephrine have the potential to be used as an easy-to-carry, palatable, non-invasive treatment for anaphylactic episodes for children in community settings.

Contemporary issues in anaphylaxis and the evolution of epinephrine autoinjectors: What will the future bring?

BACKGROUND

Food allergy and anaphylaxis appear to be increasing in the United States, especially in young children, and preparedness is paramount to successful emergency management in the community. Although the treatment of choice for anaphylaxis is epinephrine delivered by autoinjection, some devices are challenged by less user-friendly designs or pose the risk of injury, especially in young patients. Human factors engineering has played a larger role in the development of more recent epinephrine autoinjector technologies and will continue to play a role in the evolution and future design of epinephrine autoinjectors.

OBJECTIVE

To discuss contemporary issues related to the identification and management of anaphylaxis, current and future epinephrine autoinjector design, and unmet needs for the treatment of special populations, namely, young children weighing less than 15 kg.

METHODS

The literature was reviewed and select articles retrieved to support expert clinical opinions on the need for improved recognition of anaphylaxis, epinephrine autoinjector design, and unmet needs in special populations.

RESULTS

Anaphylaxis may be underrecognized and poorly defined in infant- and toddler-aged children, current devices may not be adequate to safely treat these patients (ie, inappropriate needle length), and health care professionals may not be aware of these issues.

CONCLUSION

As epinephrine autoinjector technology continues to evolve, device characteristics that promote safe, user-friendly experiences and give clinicians and their patients confidence to successfully treat anaphylaxis during an emergency, without injury, will be favored.

Formulation and Evaluation of Fast-Disintegrating Sublingual Tablets of Atropine Sulfate: the Effect of Tablet Dimensions and Drug Load on Tablet Characteristics

In this study, we formulated and evaluated the effects of tablet dimensions and drug load on the characteristics of atropine sulfate (AS) fast-disintegrating sublingual tablets (FDSTs). We aim to develop AS FDSTs as an alternative non-invasive and portable dosage form for the emergency treatment of organophosphate (OP) toxicity. AS autoinjector, AtroPen®, is the only self-administered dosage form available as an antidote for-out-of-hospital emergency use, but it is associated with several limitations and drawbacks. Seven FDST formulations of two tablet sizes, 150 mg (A) and 50 mg (B), and of several AS loads, 0 mg (A1, B1), 2 mg (A2, B2), 4 mg (B3), and 8 mg (B4a, B4b), were formulated and manufactured by direct compression. AS FDST characteristics were evaluated using USP and non-USP tests. Results were statistically compared at p < 0.05. All FDSTs passed the USP content uniformity and friability tests, disintegrated and released AS in ≤30 and 60 s. B1 and B2 were significantly harder than A1 and A2. Water uptake of A1 was significantly the highest. However, B1 and B2 had shorter disintegration and wetting times and higher amounts of AS dissolved than did A1 and A2 (p < 0.05). Increasing AS negatively affected FDST tensile strength (p < 0.05 for B4a) and water uptake (p < 0.05 for B3, B4a and B4b), however, without affecting AS dissolution. Formulation of AS up to 16% into smaller FDSTs was successful. Smaller FDSTs were harder and disintegrated more quickly. These AS FDSTS have the potential for further in vivo testing to evaluate their OP antidote potential.

Anaphylaxis in children and adolescents: The European Anaphylaxis Registry

BACKGROUND

Anaphylaxis in children and adolescents is a potentially life-threatening condition. Its heterogeneous clinical presentation and sudden occurrence in virtually any setting without warning have impeded a comprehensive description.

OBJECTIVE

We sought to characterize severe allergic reactions in terms of elicitors, symptoms, emergency treatment, and long-term management in European children and adolescents.

METHODS

The European Anaphylaxis Registry recorded details of anaphylaxis after referral for in-depth diagnosis and counseling to 1 of 90 tertiary allergy centers in 10 European countries, aiming to oversample the most severe reactions. Data were retrieved from medical records by using a multilanguage online form.

RESULTS

Between July 2007 and March 2015, anaphylaxis was identified in 1970 patients younger than 18 years. Most incidents occurred in private homes (46%) and outdoors (19%). One third of the patients had experienced anaphylaxis previously. Food items were the most frequent trigger (66%), followed by insect venom (19%). Cow's milk and hen's egg were prevalent elicitors in the first 2 years, hazelnut and cashew in preschool-aged children, and peanut at all ages. There was a continuous shift from food- to insect venom- and drug-induced anaphylaxis up to age 10 years, and there were few changes thereafter. Vomiting and cough were prevalent symptoms in the first decade of life, and subjective symptoms (nausea, throat tightness, and dizziness) were prevalent later in life. Thirty percent of cases were lay treated, of which 10% were treated with an epinephrine autoinjector. The fraction of intramuscular epinephrine in professional emergency treatment increased from 12% in 2011 to 25% in 2014. Twenty-six (1.3%) patients were either admitted to the intensive care unit or had grade IV/fatal reactions.

CONCLUSIONS

The European Anaphylaxis Registry confirmed food as the major elicitor of anaphylaxis in children, specifically hen's egg, cow's milk, and nuts. Reactions to insect venom were seen more in young adulthood. Intensive care unit admissions and grade IV/fatal reactions were rare. The registry will serve as a systematic foundation for a continuous description of this multiform condition.