Current therapeutic applications and pharmacokinetic modulations of ivermectin

Co-Processed Crystalline Solids of Ivermectin with Span® 60 as Solubility Enhancers of Ivermectin in Natural Oils

Despite being discovered over five decades ago, little is still known about ivermectin. Ivermectin has several physico-chemical properties that can result in it having poor bioavailability. In this study, polymorphic and co-crystal screening was used to see if such solid-state modifications can improve the oil solubility of ivermectin. Span® 60, a lipophilic non-ionic surfactant, was chosen as co-former. The rationale behind attempting to improve oil solubility was to use ivermectin in future topical and transdermal preparations to treat a range of skin conditions like scabies and head lice. Physical mixtures were also prepared in the same molar ratios as the co-crystal candidates, to serve as controls. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR spectra of the co-crystal candidates showed the presence of Span® 60's alkyl chain peaks, which were absent in the spectra of the physical mixtures. Due to the absence of single-crystal X-ray data, co-crystal formation could not be confirmed, and therefore these co-crystal candidates were referred to as co-processed crystalline solids. Following characterization, the solid-state forms, physical mixtures and ivermectin raw material were dissolved in natural penetration enhancers, i.e., avocado oil (AVO) and evening primrose oil (EPO). The co-processed solids showed increased oil solubility by up to 169% compared to ivermectin raw material. The results suggest that co-processing of ivermectin with Span® 60 can be used to increase its oil solubility and can be useful in the development of oil-based drug formulations.

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.

Physical and pharmacokinetic characterization of Soluvec™, a novel, solvent-free aqueous ivermectin formulation

Purpose: To describe application of the Quicksol™ solvent-free approach to solubilize ivermectin (IVM). Methods: Lyophilized IVM complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD) was resolubilized in aqueous polysorbate-80, generating Soluvec™. Lyophilizate was examined by Fourier-transform infrared spectroscopy and differential scanning calorimetry; Soluvec, by dynamic light scattering. Pharmacokinetics was evaluated in dogs allocated to subcutaneous (SC) or intramuscular (IM) Soluvec or oral IVM. Results: IVM in Soluvec was tightly bound by HPβCD, forming nearly monodisperse 28 nm particles with solubility ∼2500-times that of free IVM. SC and IM Soluvec increased IVM exposure, peak IVM and extended duration of IVM exposure, versus oral dosing. Conclusion: The Quicksol method generated Soluvec, a concentrated aqueous parenteral IVM formulation with pharmacokinetic properties suitable for veterinary or human use.

Electrochemical Characterisation and Confirmation of Antioxidative Properties of Ivermectin in Biological Medium

Ivermectin (IVM) is a drug from the group of anthelmintics used in veterinary and human medicine. Recently, interest in IVM has increased as it has been used for the treatment of some malignant diseases, as well as viral infections caused by the Zika virus, HIV-1 and SARS-CoV-2. The electrochemical behaviour of IVM was investigated using cyclic (CV), differential pulse (DPV) and square wave voltammetry (SWV) at glassy carbon electrode (GCE). IVM showed independent oxidation and reduction processes. The effect of pH and scan rate indicated the irreversibility of all processes and confirmed the diffusion character of oxidation and reduction as an adsorption-controlled process. Mechanisms for IVM oxidation at the tetrahydrofuran ring and reduction of the 1,4-diene structure in the IVM molecule are proposed. The redox behaviour of IVM in a biological matrix (human serum pool) showed a pronounced antioxidant potential similar to that of Trolox during short incubation, whereas a prolonged stay among biomolecules and in the presence of an exogenous pro-oxidant (tert-butyl hydroperoxide, TBH) resulted in a loss of its antioxidant effect. The antioxidant potential of IVM was confirmed by voltametric methodology which is proposed for the first time.

Implication of apoptosis and oxidative stress in mitigation of ivermectin long-term hazards by zinc nanoparticles in male rabbits

Ivermectin is the medication of choice for treating human onchocerciasis and is used in veterinary medicine to treat a variety of ectoparasites and endoparasites. This study was designed to investigate the effects of zinc nanoparticles (ZnNPs) on the fertility of male rabbits exposed to experimental ivermectin (IVM) intoxication. A total of 72 mature male rabbits were equally divided into 4 groups (n = 18). The first group (CTR) served as control; the second group (IVM) received subcutaneous injection of IVM (0.2 mg/kg body weight); the third group (ZnNPs) fed on zinc nanoparticles (60 mg/kg diet); and the fourth group (ZnNPs + IVM) were administered IVM and zinc nanoparticles at the same doses. The experiment lasted for 9 weeks. Results revealed that IVM-intoxicated rabbits showed impaired growth performance parameters, including body weight, total body weight gain (TBWG), total feed intake (TFI), and feed conversion ratio (FCR). Moreover, carcass characteristic and fertility parameters (including semen quality parameters and testosterone levels) were also impaired after IVM administration. Additionally, testicular malondialdehyde (MDA) and antioxidant (reduced glutathione, superoxide dismutase, catalase) levels as well as the histopathology and immunohistochemical expression of caspase 3 and PCNA in the testes and epididymis were detrimentally affected. On the contrary, ZnNP administration efficiently improved most of these parameters in IVM-intoxicated rabbits. In conclusion, ZnNPs exhibited promising ability for improving the growth and fertility status of rabbits and reducing the deleterious effects of IVM possibly through the suppression of apoptotic and oxidative pathways.

Ivermectin Attenuates CCl4-Induced Liver Fibrosis in Mice by Suppressing Hepatic Stellate Cell Activation

Liver fibrosis, a common liver dysfunction with high morbidity and mortality rates, is the leading cause of cirrhosis and hepatocellular carcinoma, for which there are no effective therapies. Ivermectin is an antiparasitic drug that also has been showing therapeutic actions in many other diseases, including antiviral and anticancer actions, as well as treating metabolic diseases. Herein, we evaluated the function of ivermectin in regulating liver fibrosis. Firstly, carbon tetrachloride (CCl₄)-injected Balb/c mice were used to assess the antifibrosis effects of ivermectin in vivo. Further, CFSC, a rat hepatic stellate cell (HSC) line, was used to explore the function of ivermectin in HSC activation in vitro. The in vivo data showed that ivermectin administration alleviated histopathological changes, improved liver function, reduced collagen deposition, and downregulated the expression of profibrotic genes. Mechanistically, the ivermectin treatment inhibited intrahepatic macrophage accumulation and suppressed the production of proinflammatory factors. Importantly, the ivermectin administration significantly decreased the protein levels of α-smooth muscle actin (α-SMA) both in vivo and in vitro, suggesting that the antifibrotic effects of ivermectin are mainly due to the promotion of HSC deactivation. The present study demonstrates that ivermectin may be a potential therapeutic agent for the prevention of hepatic fibrosis.

Central Effects of Ivermectin in Alleviation of Covid-19-induced Dysauto-nomia

Covid-19 may be associated with various neurological disorders, including dysautonomia, a dysfunction of the autonomic nervous system (ANS). In Covid-19, hypoxia, immunoinflammatory abnormality, and deregulation of the renin-angiotensin system (RAS) may increase sympathetic discharge with dysautonomia development. Direct SARS-CoV-2 cytopathic effects and associated inflammatory reaction may lead to neuroinflammation, affecting different parts of the central nervous system (CNS), including the autonomic center in the hypothalamus, causing dysautonomia. High circulating AngII, hypoxia, oxidative stress, high pro-inflammatory cytokines, and emotional stress can also provoke autonomic deregulation and high sympathetic outflow with the development of the sympathetic storm. During SARS-CoV-2 infection with neuro-invasion, GABA-ergic neurons and nicotinic acetylcholine receptor (nAChR) are inhibited in the hypothalamic pre-sympathetic neurons leading to sympathetic storm and dysautonomia. Different therapeutic modalities are applied to treat SARS-CoV-2 infection, like antiviral and anti-inflammatory drugs. Ivermectin (IVM) is a robust repurposed drug widely used to prevent and manage mild-moderate Covid-19. IVM activates both GABA-ergic neurons and nAChRs to mitigate SARS-CoV-2 infection- induced dysautonomia. Therefore, in this brief report, we try to identify the potential role of IVM in managing Covid-19-induced dysautonomia.

Ivermectin: recent approaches in the design of novel veterinary and human medicines

Ivermectin (IVM) is a drug widely used in veterinary and human medicine for the management of parasitic diseases. Its repositioning potential has been recently considered for the treatment of different diseases, such as cancer and viral infections. However, IVM faces some limitations to its formulations due to its low water solubility and bioavailability, along with reports of drug resistance. In this sense, novel technological approaches have been explored to optimize its formulations and/or to develop innovative medicines. Therefore, this review discusses the strategies proposed in the last decade to improve the safety and efficacy of IVM and to explore its novel therapeutic applications. Among these technologies, the use of micro/nano-drug delivery systems is the most used approach, followed by long-acting formulations. In general, the development of these novel formulations seems to run side by side in veterinary and human health, showing a shared interface between the two areas. Although the technologies proposed indicate a promising future in the development of innovative dosage forms containing IVM, its safety and therapeutic targets must be further evaluated. Overall, these approaches comprise tailoring drug delivery profiles, decreasing the risks of developing drug resistance, and supporting the application of IVM for reaching different therapeutic targets.

The use of Ivermectin for the treatment of COVID-19: Panacea or enigma?

The outbreak of SARS-CoV-2 pandemic has triggered unprecedented social, economic and health challenges. To control and reduce the infection rate, countries employed non-pharmaceutical measures such as social distancing, isolation, quarantine, and the use of masks, hand and surface sanitisation. Since 2021 a global race for COVID-19 vaccination ensued, mainly due to a lack of equitable vaccine production and distribution. To date, no treatments have been demonstrated to cure COVID-19. The scientific World is now considering the potential use of Ivermectin as a prophylactic and treatment for COVID-19. Against this background, the objective of this study is to review the literature to demystify the enigma or panacea in the use of Ivermectin. This paper intends to investigate literature which supports the existence or shows the nonexistence of a causal link between Ivermectin, COVID-19 mortality and recovery. There are inconsistent results on the effectiveness of Ivermectin in the treatment of COVID-19 patients. Some studies have asserted that in a bid to slow down the transmission of COVID-19, ivermectin can be used to inhibit the in vitro replication of SARS-CoV-2. The pre-existing health system burdens can be alleviated as patients treated prophylactically would reduce hospital admissions and stem the spread of COVID-19. On a global scale, Ivermectin is currently used by about 28% of the world's population, and its adoption is presently about 44% of countries. However, the full administration of this drug would require further tests to establish its clinical effectiveness and efficacy.

The epidemiology and control of Toxocara canis in puppies

Toxocara canis is a helminth zoonosis that is estimated to infect more than 100 million dogs and 1 billion people, mostly in the tropics. Humans can be infected by accidentally ingesting embryonated T. canis eggs from the environment or occasionally after ingesting L₃ larvae from paratenic hosts. This study investigated the importance of vertical transmission and the role of puppies in the epidemiology of T. canis through the examination of fecal samples from dogs less than one year of age in Grenada, West Indies, a small island tropical developing country. Samples were stored at 4 °C or in 10% formalin until microscopic examination for helminth eggs or using a rapid antigen test for the presence of protozoan species. A knowledge, attitudes and practices study was completed among dog owners, physicians and veterinary students. Of 306 dogs less than one year of age, 147 (48%) were found to have T. canis eggs. Vertical transmission was indicated by the proportion of infected dogs increasing from 50% at two weeks of age (from in utero transmission) to 70% by 12 weeks (in utero and lactogenic transmission). After 12 weeks the positivity rate dropped rapidly with no dogs over 40 weeks of age being infected. As T. canis eggs were found in puppy feces at two weeks of age, initial treatment of puppies should begin earlier, at twelve days post-partum, than currently recommended to prevent shedding of eggs. Perhaps even more importantly, treatment of pregnant dogs, preventing vertical transmission, would have a major impact on the control of T. canis infection. Knowledge of T. canis and other zoonotic helminths such as Ancylostoma caninum was found to be low among dog owners, physicians and veterinary students. None of the dog owners treated their dogs for helminths, all were unaware of the risk of zoonoses, and only 9% picked up dog feces. Efforts to prevent vertical transmission and to increase awareness and knowledge of these zoonoses could result in reducing their public health impact.

In vitro larvicidal activity of ivermectin and povidone-iodine against Oestrus ovis

Purpose

To assess the in vitro larvicidal activity of ivermectin and povidone-iodine (PVP-I) against Oestrus ovis, the most frequent cause of external ophthalmomyiasis.

Methods

L1 O. ovis larvae were collected from the nasal boots of sheep slaughtered in local abattoirs and transferred onto Petri dishes containing mucosal tissue (25 larvae/dish). The larvicidal activity of the following formulations was tested: 1% ivermectin suspension in balanced sterile saline solution (BSSS), 1% ivermectin solution in propylene glycol, propylene glycol, 0.6% PVP-I in hyaluronic acid vehicle (IODIM®), and combination of ivermectin 1% solution and 0.6% PVP-I. One mL of each formulation was added to different Petri dishes containing the larvae. The time needed to kill the larvae was recorded.

Results

893 larvae were tested. The median time needed to kill the larvae was 46, 44, 11, 6, and 10 minutes for Iodim®, ivermectin 1% suspension, propylene glycol, ivermectin 1% solution, and a combination of ivermectin 1% solution with 0.6% PVP-I, respectively. Kaplan-Meyer analysis disclosed that the survival curves were significantly lower in samples treated with ivermectin 1% solution, ivermectin 1% solution + 0.6% PVP-I, and propylene glycol than in samples receiving other treatments or BSSS.

Conclusion

In this in vitro study, ivermectin 1% solution in propylene glycol, ivermectin 1% solution + 0.6% PVP-I, and propylene glycol alone showed a good, relatively rapid larvicidal activity against O. ovis larvae. Further experimental and clinical studies are necessary to establish whether, or not, these formulations may be considered as potential candidates for the topical treatment for external ophthalmomyiasis caused by O. ovis.

Marine Actinomycetes, New Sources of Biotechnological Products

The Actinomycetales order is one of great genetic and functional diversity, including diversity in the production of secondary metabolites which have uses in medical, environmental rehabilitation, and industrial applications. Secondary metabolites produced by actinomycete species are an abundant source of antibiotics, antitumor agents, anthelmintics, and antifungals. These actinomycete-derived medicines are in circulation as current treatments, but actinomycetes are also being explored as potential sources of new compounds to combat multidrug resistance in pathogenic bacteria. Actinomycetes as a potential to solve environmental concerns is another area of recent investigation, particularly their utility in the bioremediation of pesticides, toxic metals, radioactive wastes, and biofouling. Other applications include biofuels, detergents, and food preservatives/additives. Exploring other unique properties of actinomycetes will allow for a deeper understanding of this interesting taxonomic group. Combined with genetic engineering, microbial experimental evolution, and other enhancement techniques, it is reasonable to assume that the use of marine actinomycetes will continue to increase. Novel products will begin to be developed for diverse applied research purposes, including zymology and enology. This paper outlines the current knowledge of actinomycete usage in applied research, focusing on marine isolates and providing direction for future research.

Metabolism and interactions of Ivermectin with human cytochrome P450 enzymes and drug transporters, possible adverse and toxic effects

The review presents metabolic properties of Ivermectin (IVM) as substrate and inhibitor of human P450 (P450, CYP) enzymes and drug transporters. IVM is metabolized, both in vivo and in vitro, by C-hydroxylation and O-demethylation reactions catalyzed by P450 3A4 as the major enzyme, with a contribution of P450 3A5 and 2C9. In samples from both in vitro and in vivo metabolism, a number of metabolites were detected and as major identified metabolites were 3″-O-demethylated, C4-methyl hydroxylated, C25 isobutyl-/isopropyl-hydroxylated, and products of oxidation reactions. Ivermectin inhibited P450 2C9, 2C19, 2D6, and CYP3A4 with IC₅₀ values ranging from 5.3 μM to no inhibition suggesting that it is no or weak inhibitor of the enzymes. It is suggested that P-gp (MDR1) transporter participate in IVM efflux at low drug concentration with a slow transport rate. At the higher, micromolar concentration range, which saturates MDR1 (P-gp), MRP1, and to a lesser extent, MRP2 and MRP3 participate in IVM transport across physiological barriers. IVM exerts a potent inhibition of P-gp (ABCB1), MRP1 (ABCC1), MRP2 (ABCC2), and BCRP1 (ABCG2), and medium to weak inhibition of OATP1B1 (SLC21A6) and OATP1B3 (SLCOB3) transport activity. The metabolic and transport properties of IVM indicate that when IVM is co-administered with other drugs/chemicals that are potent inhibitors/inducers P4503A4 enzyme and of MDR1 (P-gp), BCRP or MRP transporters, or when polymorphisms of the drug transporters and P450 3A4 exist, drug–drug or drug–toxic chemical interactions might result in suboptimal response to the therapy or to toxic effects.

A Scoping Insight on Potential Prophylactics, Vaccines and Therapeutic Weaponry for the Ongoing Novel Coronavirus (COVID-19) Pandemic- A Comprehensive Review

The emergence of highly virulent CoVs (SARS-CoV-2), the etiologic agent of novel ongoing "COVID-19" pandemics has been marked as an alarming case of pneumonia posing a large global healthcare crisis of unprecedented magnitude. Currently, the COVID-19 outbreak has fueled an international demand in the biomedical field for the mitigation of the fast-spreading illness, all through the urgent deployment of safe, effective, and rational therapeutic strategies along with epidemiological control. Confronted with such contagious respiratory distress, the global population has taken significant steps towards a more robust strategy of containment and quarantine to halt the total number of positive cases but such a strategy can only delay the spread. A substantial number of potential vaccine candidates are undergoing multiple clinical trials to combat COVID-19 disease, includes live-attenuated, inactivated, viral-vectored based, sub-unit vaccines, DNA, mRNA, peptide, adjuvant, plant, and nanoparticle-based vaccines. However, there are no licensed anti-COVID-19 drugs/therapies or vaccines that have proven to work as more effective therapeutic candidates in open-label clinical trial studies. To counteract the infection (SARS-CoV-2), many people are under prolonged treatment of many chemical drugs that inhibit the PLpro activity (Ribavirin), viral proteases (Lopinavir/Ritonavir), RdRp activity (Favipiravir, Remdesivir), viral membrane fusion (Umifenovir, Chloroquine phosphate (CQ), Hydroxychloroquine phosphate (HCQ), IL-6 overexpression (Tocilizumab, Siltuximab, Sarilumab). Mesenchymal Stem Cell therapy and Convalescent Plasma Therapy have emerged as a promising therapeutic strategy against SARS-CoV-2 virion. On the other hand, repurposing previously designed antiviral agents with tolerable safety profile and efficacy could be the only promising approach and fast response to the novel virion. In addition, research institutions and corporations have commenced the redesign of the available therapeutic strategy to manage the global crisis. Herein, we present succinct information on selected anti-COVID-19 therapeutic medications repurposed to combat SARS-CoV-2 infection. Finally, this review will provide exhaustive detail on recent prophylactic strategies and ongoing clinical trials to curb this deadly pandemic, outlining the major therapeutic areas for researchers to step in.

Innovative anthelmintic based on mechanochemical technology and their efficacy against parasitic infection of sheeps

Objective:

Solubility and bioavailability are crucial for maximizing the activity of an antiparasitic drug. This study aimed to develop a combined preparation for antiparasitic medicines using ivermectin (Iver), fenbendazole (FBZ), and triclabendazole (TBZ), considering their solubility, bioavailability, and activity.

Materials and Methods:

Innovative preparations in solid dispersions (SD) were obtained using the joint mechanical processing of drug substances with polyvinylpyrrolidone (PVP) in an LE-101 roller mill. The preparations’ efficacy was studied in 140 sheep spontaneously infected with gastrointestinal Strongylata, Dicrococelium dendriticum, Moniezia expansa, and Melophagus ovinus. The preparations were given individually to the sheep in the form of an aqueous suspension orally. Their effectiveness was evaluated using intravital and postmortem parasitological examinations.

Results:

The results confirmed the increase in solubility of substances by 13–29 times. The experiments have shown the high efficacy of SD composition of FBZ/Iver/PVP (1/1/9) containing FBZ (at 3.0 mg/kg b/w) and Iver (at 0.2 mg/kg b/w) when used against gastrointestinal Strongylates and M. expansa (95.8% and 100%, respectively), to a lesser extent against M. ovinus (38.5%). The SD composition of TBZ/Iver/PVP (1/1/9) of TBZ (at 3.0 mg/kg b/w) and Iver (at 0.2 mg/kg b/w) showed a high efficacy against gastrointestinal Strongylata and D. dendriticum (96.8% and 100%, respectively) and less activity against M. ovinus (61.6%).

Conclusion:

The high parasiticidal activity of SD based on FBZ, TBZ, and Iver in comparison with initial substances is explained by the formation of inclusion complexes of these substances with PVP when SD is dissolved in water and the synergistic effect of the active substances of the preparations. The resulting complexes have increased solubility in water and bioavailability. The use of such an SD suggests a significant reduction in the dosages of FBZ and TBZ without losing parasiticidal activity.

Sustained-release hydrogels of ivermectin as alternative systems to improve the treatment of cutaneous leishmaniasis

Background: Leishmaniasis is a neglected tropical disease and its cutaneous form manifests as ulcers or nodules, generally in exposed parts of the body. This work aimed to develop ivermectin (IVM) thermosensitive hydrogels as topical formulations to improve cutaneous leishmaniasis treatment. Materials & methods: Hydrogels based on poloxamers 407 and 188 with different concentrations of IVM were prepared and rheologically characterized. The IVM release profiles were obtained and mathematically analyzed using the Lumped model. Results: The formulation containing 1.5% w/w of IVM presented an adequate gelling temperature, an optimal complex viscosity and elastic modulus. Hydrogels allowed to modulate the release of IVM. Conclusion: IVM thermosensitive hydrogels can be considered a valuable alternative to improve the treatment of cutaneous leishmaniasis.

Coronavirus Disease 2019-COVID-19

SUMMARYIn recent decades, several new diseases have emerged in different geographical areas, with pathogens including Ebola virus, Zika virus, Nipah virus, and coronaviruses (CoVs). Recently, a new type of viral infection emerged in Wuhan City, China, and initial genomic sequencing data of this virus do not match with previously sequenced CoVs, suggesting a novel CoV strain (2019-nCoV), which has now been termed severe acute respiratory syndrome CoV-2 (SARS-CoV-2). Although coronavirus disease 2019 (COVID-19) is suspected to originate from an animal host (zoonotic origin) followed by human-to-human transmission, the possibility of other routes should not be ruled out. Compared to diseases caused by previously known human CoVs, COVID-19 shows less severe pathogenesis but higher transmission competence, as is evident from the continuously increasing number of confirmed cases globally. Compared to other emerging viruses, such as Ebola virus, avian H7N9, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV-2 has shown relatively low pathogenicity and moderate transmissibility. Codon usage studies suggest that this novel virus has been transferred from an animal source, such as bats. Early diagnosis by real-time PCR and next-generation sequencing has facilitated the identification of the pathogen at an early stage. Since no antiviral drug or vaccine exists to treat or prevent SARS-CoV-2, potential therapeutic strategies that are currently being evaluated predominantly stem from previous experience with treating SARS-CoV, MERS-CoV, and other emerging viral diseases. In this review, we address epidemiological, diagnostic, clinical, and therapeutic aspects, including perspectives of vaccines and preventive measures that have already been globally recommended to counter this pandemic virus.

Coronavirus Disease 2019-COVID-19

SUMMARYIn recent decades, several new diseases have emerged in different geographical areas, with pathogens including Ebola virus, Zika virus, Nipah virus, and coronaviruses (CoVs). Recently, a new type of viral infection emerged in Wuhan City, China, and initial genomic sequencing data of this virus do not match with previously sequenced CoVs, suggesting a novel CoV strain (2019-nCoV), which has now been termed severe acute respiratory syndrome CoV-2 (SARS-CoV-2). Although coronavirus disease 2019 (COVID-19) is suspected to originate from an animal host (zoonotic origin) followed by human-to-human transmission, the possibility of other routes should not be ruled out. Compared to diseases caused by previously known human CoVs, COVID-19 shows less severe pathogenesis but higher transmission competence, as is evident from the continuously increasing number of confirmed cases globally. Compared to other emerging viruses, such as Ebola virus, avian H7N9, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV-2 has shown relatively low pathogenicity and moderate transmissibility. Codon usage studies suggest that this novel virus has been transferred from an animal source, such as bats. Early diagnosis by real-time PCR and next-generation sequencing has facilitated the identification of the pathogen at an early stage. Since no antiviral drug or vaccine exists to treat or prevent SARS-CoV-2, potential therapeutic strategies that are currently being evaluated predominantly stem from previous experience with treating SARS-CoV, MERS-CoV, and other emerging viral diseases. In this review, we address epidemiological, diagnostic, clinical, and therapeutic aspects, including perspectives of vaccines and preventive measures that have already been globally recommended to counter this pandemic virus.

Coronavirus Disease 2019-COVID-19

SUMMARYIn recent decades, several new diseases have emerged in different geographical areas, with pathogens including Ebola virus, Zika virus, Nipah virus, and coronaviruses (CoVs). Recently, a new type of viral infection emerged in Wuhan City, China, and initial genomic sequencing data of this virus do not match with previously sequenced CoVs, suggesting a novel CoV strain (2019-nCoV), which has now been termed severe acute respiratory syndrome CoV-2 (SARS-CoV-2). Although coronavirus disease 2019 (COVID-19) is suspected to originate from an animal host (zoonotic origin) followed by human-to-human transmission, the possibility of other routes should not be ruled out. Compared to diseases caused by previously known human CoVs, COVID-19 shows less severe pathogenesis but higher transmission competence, as is evident from the continuously increasing number of confirmed cases globally. Compared to other emerging viruses, such as Ebola virus, avian H7N9, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV-2 has shown relatively low pathogenicity and moderate transmissibility. Codon usage studies suggest that this novel virus has been transferred from an animal source, such as bats. Early diagnosis by real-time PCR and next-generation sequencing has facilitated the identification of the pathogen at an early stage. Since no antiviral drug or vaccine exists to treat or prevent SARS-CoV-2, potential therapeutic strategies that are currently being evaluated predominantly stem from previous experience with treating SARS-CoV, MERS-CoV, and other emerging viral diseases. In this review, we address epidemiological, diagnostic, clinical, and therapeutic aspects, including perspectives of vaccines and preventive measures that have already been globally recommended to counter this pandemic virus.

Microemulsion systems to enhance the transdermal permeation of ivermectin in dogs: A preliminary in vitro study

This study aims to evaluate the influence of the phase behavior of microemulsions in the transdermal administration ("spot-on") of ivermectin, an antiparasitic drug widely used in the treatment of endoparasites and ectoparasites in dogs. In this regard, pseudoternary phase diagrams composed of water (aqueous phase), isopropyl myristate (oil phase), tween 80 (surfactant) and labrasol (cosurfactant) were obtained in a different surfactant: cosurfactant (S:CS) ratios. S:CS in 1:3 ratio presented a larger region of microemulsion formation and three microemulsions were selected from it and characterized. Subsequently, in vitro permeation and retention studies were conducted using canine skin as membrane. SAXS, rheology and conductivity data were employed to confirm the phase behavior of the microemulsions (w/o, bicontinuous or o/w). The cutaneous permeation and retention tests showed that the w/o microemulsion, followed by bicontinuous microemulsion, resulted in a higher amount of drug permeated through canine skin, suggesting better transdermal permeation. On the other hand, o/w microemulsion resulted in a higher amount of drug accumulated into the skin, suggesting better topical activity. Thus, it can be concluded that phase behavior of microemulsions influenced the drug permeation in the canine skin differently from other animal models. Microemulsions, especially w/o and bicontinuous, can be promising vehicles regarding the transdermal delivery of ivermectin.