Subcutaneously injected ivermectin-loaded mixed micelles: formulation, pharmacokinetics and local irritation study

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.

Ameliorating the antiparasitic activity of the multifaceted drug ivermectin through a polymer nanocapsule formulation

Ivermectin (IVM) is a potent antiparasitic widely used in human and veterinary medicine. However, the low oral bioavailability of IVM restricts its therapeutic potential in many parasitic infections, highlighting the need for novel formulation approaches. In this study, poly(ε-caprolactone) (PCL) nanocapsules containing IVM were successfully developed using the nanoprecipitation method. Pumpkin seed oil (PSO) was used as an oily core in the developed nanocapsules. Previously, PSO was chemically analyzed by headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry (HS-SPME/GC-MS). The solubility of IVM in PSO was found to be 4,266.5 ± 38.6 μg/mL. In addition, the partition coefficient of IVM in PSO/water presented a logP of 2.44. A number of nanocapsule batches were produced by factorial design resulting in an optimized formulation. Negatively charged nanocapsules measuring around 400 nm demonstrated unimodal size distribution, and presented regular spherical morphology under transmission electron microscopy. High encapsulation efficiency (98-100%) was determined by HPLC. IVM-loaded capsules were found to be stable in nanosuspensions at 4°C and 25°C, with no significant variations in particle size observed over a period of 150 days. Nanoencapsulated IVM (0.3 mM) presented reduced toxicity to J774 macrophages and L929 fibroblasts compared to free IVM. Moreover, IVM-loaded nanocapsules also demonstrated enhanced in vitro anthelmintic activity against Strongyloides venezuelensis in comparison to free IVM. Collectively, the present findings demonstrate the promising potential of PCL-PSO nanocapsules to improve the antiparasitic effects exerted by IVM.

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.

Manipulation of Spray-Drying Conditions to Develop an Inhalable Ivermectin Dry Powder

SARS-CoV-2, the causative agent of COVID-19, predominantly affects the respiratory tract. As a consequence, it seems intuitive to develop antiviral agents capable of targeting the virus right on its main anatomical site of replication. Ivermectin, a U.S. FDA-approved anti-parasitic drug, was originally shown to inhibit SARS-CoV-2 replication in vitro, albeit at relatively high concentrations, which is difficult to achieve in the lung. In this study, we tested the spray-drying conditions to develop an inhalable dry powder formulation that could ensure sufficient antiviral drug concentrations, which are difficult to achieve in the lungs based on the oral dosage used in clinical trials. Here, by using ivermectin as a proof-of-concept, we evaluated spray-drying conditions that could lead to the development of antivirals in an inhalable dry powder formulation, which could then be used to ensure sufficient drug concentrations in the lung. Thus, we used ivermectin in proof-of-principle experiments to evaluate our system, including physical characterization and in vitro aerosolization of prepared dry powder. The ivermectin dry powder was prepared with a mini spray-dryer (Buchi B-290), using a 23 factorial design and manipulating spray-drying conditions such as feed concentration (0.2% w/v and 0.8% w/v), inlet temperature (80 °C and 100 °C) and presence/absence of L-leucine (0% and 10%). The prepared dry powder was in the size range of 1−5 μm and amorphous in nature with wrinkle morphology. We observed a higher fine particle fraction (82.5 ± 1.4%) in high feed concentration (0.8% w/v), high inlet temperature (100 °C) and the presence of L-leucine (10% w/w). The stability study conducted for 28 days confirmed that the spray-dried powder was stable at 25 ± 2 °C/<15% RH and 25 ± 2 °C/ 53% RH. Interestingly, the ivermectin dry powder formulation inhibited SARS-CoV-2 replication in vitro with a potency similar to ivermectin solution (EC50 values of 15.8 µM and 14.1 µM, respectively), with a comparable cell toxicity profile in Calu-3 cells. In summary, we were able to manipulate the spray-drying conditions to develop an effective ivermectin inhalable dry powder. Ongoing studies based on this system will allow the development of novel formulations based on single or combinations of drugs that could be used to inhibit SARS-CoV-2 replication in the respiratory tract.

Niosomal versus nano-crystalline ivermectin against different stages of Trichinella spiralis infection in mice

Ivermectin (IVM) is one of the competitive treatments used for trichinellosis. However, several studies linked its efficacy with early diagnosis and administration to tackle the intestinal phase with limited activity being recorded against encysted larvae. The aim of this study was to employ niosomes for enhancing effectiveness of oral IVM against different stages of Trichinella spiralis (T. spiralis) infection with reference to nano-crystalline IVM. Mice were randomized into four groups: group Ι, 15 uninfected controls; group ΙΙ, 30 infected untreated controls; group ΙΙΙ, 30 infected nano-crystalline IVM treated, and group ΙV, 30 infected niosomal IVM treated. All groups were equally subdivided into 3 subgroups; (a) treated on the 1^st day post infection (dpi), (b) treated on the 10^th dpi, and (c) treated on the 30^th dpi. Assessment was done by counting adult worms and larvae plus histopathological examination of jejunum and diaphragm. Biochemical assessment of oxidant/antioxidant status, angiogenic, and inflammatory biomarkers in intestinal and muscle tissues was also performed. Both niosomes and nano-crystals resulted in significant reduction in adult and larval counts compared to the infected untreated control with superior activity of niosomal IVM. The superiority of niosomes was expressed further by reduction of inflammation in both jejunal and muscle homogenates. Biochemical parameters showed highly significant differences in all treated mice compared to infected untreated control at different stages with highly significant effect of niosomal IVM. In conclusion, niosomal IVM efficacy exceeded the nano-crystalline IVM in treatment of different phases of trichinellosis.

Current therapeutic applications and pharmacokinetic modulations of ivermectin

Ivermectin is considered to be a wonder drug due to its broad-spectrum antiparasitic activity against both ectoparasites and endoparasites (under class of endectocide) and has multiple applications in both veterinary and human medicine. In particular, ivermectin is commonly used in the treatment of different kinds of infections and infestations. By altering the vehicles used in the formulations, the pharmacokinetic properties of different ivermectin preparations can be altered. Since its development, various vehicles have been evaluated to assess the efficacy, safety, and therapeutic systemic concentrations of ivermectin in different species. A subcutaneous route of administration is preferred over a topical or an oral route for ivermectin due to superior bioavailability. Different formulations of ivermectin have been developed over the years, such as stabilized aqueous formulations, osmotic pumps, controlled release capsules, silicone carriers, zein microspheres, biodegradable microparticulate drug delivery systems, lipid nanocapsules, solid lipid nanoparticles, sustained-release ivermectin varnish, sustained-release ivermectin-loaded solid dispersion suspension, and biodegradable subcutaneous implants. However, several reports of ivermectin resistance have been identified in different parts of the world over the past few years. Continuous use of suboptimal formulations or sub-therapeutic plasma concentrations may predispose an individual to resistance toward ivermectin. The current research trend is focused toward the need for developing ivermectin formulations that are stable, effective, and safe and that reduce the number of doses required for complete clinical cure in different parasitic diseases. Therefore, single-dose long-acting preparations of ivermectin that provide effective therapeutic drug concentrations need to be developed and commercialized, which may revolutionize drug therapy and prophylaxis against various parasitic diseases in the near future. The present review highlights the current advances in pharmacokinetic modulation of ivermectin formulations and their potent therapeutic applications, issues related to emergence of ivermectin resistance, and future trends of ivermectin usage.

Self-implanted tiny needles as alternative to traditional parenteral administrations for controlled transdermal drug delivery

Controlled drug-delivery systems have potential as substitutes for traditional medication systems due to the advantages in safety, efficacy, and patient compliance that these long-acting dosage forms provide. In this context, the present study focus on the development of self-implanted hyaluronic acid (HA) tiny needles that encapsulate ivermectin (IVM)-poly (lactic-co-glycolic acid) (PLGA) microparticles for controlled transdermal IVM release to treat parasitic diseases. The fabricated tiny needles involved matching portable applicator have potentially able for self-administration by patients without intense pain or complexity of current controlled-release devices. The biodegradable IVM-loaded PLGA microparticles were prepared and encapsulated within the tip of dissolving HA tiny needles to achieve high delivery efficiency. The drug loading of tiny needles might be controlled by varying the repeat time of filling or pressing processes. In-vitro tests showed that the tiny needles have sufficient mechanical strength to be inserted into skin within seconds and, next rapidly dissolved to release the loaded drug carriers into subcutaneous tissues for intradermal sustained IVM release. With the in-vivo test in rats, the insertion site recovered barrier property within 3 h. In comparison to traditional hypodermic injection or implantation of controlled-release systems, the proposed polymer tiny needles can be considered as a promising device for controlled transdermal drug delivery.

Preparation of ginsenoside compound-K mixed micelles with improved retention and antitumor efficacy

Introduction

Ginsenoside compound K (CK) has effects on cell-cycle regulation, tumor growth inhibition, and apoptosis induction. However, it has limited applications in clinical settings because of its low solubility and poor absorption.

Methods

To overcome these limitations, we aimed to develop a mixed micellar system composed of phosphatidylcholine (PC) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine polyethylene glycol 2000 (DSPE PEG 2000; DP). CK encapsulated in PC/DP mixed micelles had enhanced solubility, permeability, and retention effects.

Results

Compared to free CK, the CK PC/DP micellar system exhibited improved anticancer effects in vitro, including cell-cycle arrest, apoptosis, and anti-invasion in human lung carcinoma A549 cells. The significant proapoptotic effect was reflected by increased chromosomal condensation, annexin V/propidium iodide staining, and related protein expression. In vitro cellular uptake and optical mouse imaging in vivo suggested that the improved antitumor effect was caused primarily by enhanced uptake and tumor targeting. Furthermore, an in vivo antitumor efficacy study indicated that the CK mixed micelles significantly inhibited tumor growth, thereby decreasing tumor volume at the end of the experiment as compared with that in the control mice. Histological analysis confirmed the antitumor effect with low toxicity.

Conclusion

The PC/DP micellar system was an effective drug delivery system for CK in tumor therapy.

Nanomedicine Approaches Against Parasitic Worm Infections

Nanomedicine approaches have the potential to transform the battle against parasitic worm (helminth) infections, a major global health scourge from which billions are currently suffering. It is anticipated that the intersection of two currently disparate fields, nanomedicine and helminth biology, will constitute a new frontier in science and technology. This progress report surveys current innovations in these research fields and discusses research opportunities. In particular, the focus is on: (1) major challenges that helminth infections impose on mankind; (2) key aspects of helminth biology that inform future research directions; (3) efforts to construct nanodelivery platforms to target drugs and genes to helminths hidden in their hosts; (4) attempts in applying nanotechnology to enable vaccination against helminth infections; (5) outlooks in utilizing nanoparticles to enhance immunomodulatory activities of worm-derived factors to cure allergy and autoimmune diseases. In each section, achievements are summarized, limitations are explored, and future directions are assessed.

Sustained release ivermectin-loaded solid lipid dispersion for subcutaneous delivery: in vitro and in vivo evaluation

This work aimed to develop a sustained release solid dispersion of ivermectin (IVM-SD) in a lipid matrix (hydrogenated castor oil, HCO) for subcutaneous delivery. Solvent-melting technology was employed to prepare IVM-SDs using HCO. The physicochemical properties of the IVM-SDs were evaluated by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), and Fourier transform infrared spectroscopy (FTIR). The release of IVM from IVM-SDs was evaluated with HPLC in vitro. Pharmacokinetics of IVM was studied in rabbits following a single subcutaneous administration of IVM-SD formulations. The efficacy of IVM-SD against the ear mange mite was evaluated in rabbits. IVM was completely dispersed in HCO in an amorphous state at a drug:carrier ratio lower than 1:3. No chemical interactions between drug and carrier were found besides hydrogen bonding for the amorphous IVM-SDs. The amorphous IVM-SDs formulations exhibited a sustained release of IVM versus physical mixtures (PMs) of IVM and HCO. The drug release decreased as the drug:carrier ratios decreased, and the release kinetics of IVM were controlled via diffusion. Cytotoxicity of IVM-SD to MDCK cells was lower than native IVM. The IVM plasma concentration of SD1:3 remained above 1 ng/mL for 49 d. Higher AUC, MRT, and T_max values were obtained at a SD1:3 relative to the IVM group. The IVM-SD improved almost 1.1-fold bioavailability of drug compared with IVM in rabbits. IVM-SD could provide longer persistence against rabbit’s ear mites than a commercial IVM injection. This study shows that these solid lipid dispersions are a promising approach for the development of subcutaneous IVM formulations.

Formulation development and systematic optimization of stabilized ziprasidone hydrochloride capsules devoid of any food effect

CONTEXT AND OBJECTIVE

The objective of the study was to develop a stable capsule formulation of ziprasidone hydrochloride which can be administered without regards to food intake.

MATERIALS AND METHODS

The unstable anhydrous form of ziprasidone hydrochloride was stabilized employing hot-melt extrusion and further optimized by 3² central composite design. The formulation was optimized after establishing acceptable ranges for response variables like disintegration time, dissolution and impurity profile. A crossover fasted and fed in vivo study was conducted in human volunteers to assess the food-effect of optimized formulation vis-à-vis the marketed brand.

RESULTS AND DISCUSSION

The optimized formulation met in-house specifications for various response variables. Further, high values of correlation coefficient vouch the adequate selection of experimental design and its high prognostic ability. In our study, no significant difference was observed between the C_max and AUC values after administration of the optimized formulation in fasted and fed states. On the contrary, there was a statistically significant increase in the C_max and AUC values after oral administration of Zeldox in fed state in comparison to fasted state.

CONCLUSIONS

The present study describes the successful development of a stable formulation of 20 mg of ziprasidone devoid of any food-effects.