ChAdOx1-S adenoviral vector vaccine applied intranasally elicits superior mucosal immunity compared to the intramuscular route of vaccination.

COVID-19 vaccines prevent severe forms of the disease, but do not warrant complete protection against breakthrough infections. This could be due to suboptimal mucosal immunity at the site of virus entry, given that all currently approved vaccines are administered via the intramuscular route. In this study, we assessed humoral and cellular immune responses in BALB/c mice after intranasal and intramuscular immunization with adenoviral vector ChAdOx1-S expressing full-length Spike protein of SARS-CoV-2. We showed that both routes of vaccination induced a potent IgG antibody response, as well as robust neutralizing capacity, but intranasal vaccination elicited a superior IgA antibody titer in the sera and in the respiratory mucosa. Bronchoalveolar lavage from intranasally immunized mice efficiently neutralized SARS-CoV-2, which has not been the case in intramuscularly immunized group. Moreover, substantially higher percentages of epitope-specific CD8 T cells exhibiting a tissue resident phenotype were found in the lungs of intranasally immunized animals. Finally, both intranasal and intramuscular vaccination with ChAdOx1-S efficiently protected the mice after the challenge with recombinant herpesvirus expressing the Spike protein. Our results demonstrate that intranasal application of adenoviral vector ChAdOx1-S induces superior mucosal immunity and therefore could be a promising strategy for putting the COVID-19 pandemic under control.

Comprehensive evaluation of xylometazoline hydrochloride formulations: Ex-vivo and in-vitro studies.

Xylometazoline is a well-established nasal decongestant that has been used alone and in combination with dexpanthenol as an over the counter (OTC) medicine. Considering the possibility of further improvement of xylometazoline nasal formulations, hyaluronic acid (HA) was evaluated as an additional ingredient. The aim of this study was to investigate the permeation, mucosal retention, and mucoadhesion properties of a new xylometazoline-HA [Xylo-HA] formulation ex vivo and to explore the potential benefits of incorporating HA in the formulation in vitro. Sheep nasal mucosa was used in the ex vivo study, where Xylo-HA was compared with xylometazoline alone [Xylo-Mono], and in combination with dexpanthenol [Xylo-Dex] to understand the impact of formulation changes. The permeation of xylometazoline was generally low (Xylo-Mono 11.14 ± 4.75 %, Xylo-HA 14.57 ± 5.72 % and Xylo-Dex 11.00 ± 3.05 % of the applied dose). The steady state fluxes of xylometazoline were determined as 12.64 ± 3.52 µg/cm2h, 14.94 ± 3.38 µg/cm2h and 12.19 ± 2.05 µg/cm2h for Xylo-Mono, Xylo-HA and Xylo-Dex, respectively. No significant differences were observed between the formulations in the permeation nor mucosal retention studies (p > 0.05 for all), while Xylo-HA exhibited superior mucoadhesive proprieties (p < 0.05 for all). The effects on wound healing and barrier integrity of the three xylometazoline formulations were tested in vitro on HaCaT cells. To better elucidate the role of HA, an additional HA formulation without xylometazoline was prepared (HA-Mono). A scratch test was performed to evaluate wound healing, revealing that the test formulations did not achieve complete wound closure within 72 h and demonstrated a similar effect at the end of the testing period. To assess the effect on barrier integrity, cells were treated for 5 days with daily measurements of transepithelial electrical resistance (TEER). At the end of the experiment, Xylo-Dex showed a moderate 14 % increase in TEER, while Xylo-Mono did not significantly affect this parameter. TEER rose by 951 % in the Xylo-HA, and by 10497 % in the HA group, suggesting that incorporating HA led to enhanced barrier function. Further clinical studies are recommended to better understand the clinical implications and efficacy of the Xylo-HA formulation, with particular focus on the role of HA.

Novel nasal formulation of xylometazoline with hyaluronic acid: In vitro ciliary beat frequency study.

Acute viral rhinosinusitis (viral ARS), or commonly referred to as the "common cold", is caused by respiratory viruses that cause disruption of the airway epithelial barrier and mucociliary dysfunction. Treatment of ARS is mainly symptomatic, with xylometazoline, a direct-acting α-adrenoceptor agonist, commonly used as a nasal decongestant. Unfortunately, this treatment does not resolve the epithelial dysfunction observed in ARS, and its use might negatively impact the nasal mucosa causing issues such as dryness, stinging, burning, rebound congestion, as well as atrophy. In light of this, a novel nasal spray formulation containing both xylometazoline and hyaluronic acid (HA) was developed to provide a more effective and safer treatment for viral ARS. HA is a natural polysaccharide known to hydrate and moisturise the upper respiratory tract, maintain the integrity of the nasal mucosa, and promote mucociliary clearance and wound healing. To investigate the potential of this combination, this study was conducted using the nasal MucilAirTMin vitro model and high-speed phase-contrast microscopy to examine the effect of xylometazoline and HA on ciliary function by measuring ciliary beat frequency and their cytotoxicity by morphological, histological and ultrastructural analysis. This research is the first to assess the effects of a specific dose and molecular weight of HA as an active pharmaceutical ingredient in nasal spray formulations. The combination of a fast-acting decongestant and an additional active agent targeting nasal epithelial dysfunction has the potential to provide an improved, reliable and safe treatment for viral ARS, and may serve as the basis for future clinical studies.

Classification of torasemide based on the Biopharmaceutics Classification System and evaluation of the FDA biowaiver provision for generic products of CLASS I drugs.

The biopharmaceutical properties of an in-house developed new crystal modification of torasemide (Torasemide N) were investigated in comparison with the most well known crystal modification form of torasemide (Torasemide I) in order to classify the drug according to the Biopharmaceutics Classification System (BCS), and to evaluate the data in line with current US Food and Drug Administration (FDA) guidance (with biowaiver provision for Class I drugs) to determine if the biowaiver provision could be improved. The solubility profiles of Torasemide I and Torasemide N were determined, and tablets prepared from both forms of the drug were studied for in-vitro release characteristics in media recommended by the current FDA guidance for biowaiver of generic products, and in other media considered more appropriate for the purpose than the ones recommended by the FDA. Two separate bioequivalence studies in healthy humans (following oral administration) were performed with two test products (both prepared from Torasemide I) against a single reference product (prepared from Torasemide N). The absorption profiles of the drug from the tablets were determined by deconvolution for comparison with the in-vitro release profiles to determine the appropriateness of some dissolution media for predicting in-vivo performance and to determine the comparative rate and extent of absorption. The drug was absorbed from the tested products quickly and almost completely (about 95% within 3.5 h of administration). However, one test product failed to meet the bioequivalence criteria and had a significant initial lower absorption rate profile compared with the reference product (P< or =0.05), whereas the other product was bioequivalent and had a similar absorption profile to the reference product. A dissolution medium at pH 5.0, in which torasemide has minimum solubility, was found to be more discriminatory than the media recommended by the FDA. Torasemide has been classified as a Class I drug according to the BCS up to a maximum dose of 40 mg and the data suggest that the current FDA guidance could be improved by giving more emphasis to selection of appropriate dissolution media than is given in its current form for approving biowaiver to generic products of Class I drugs.

Application of hot-melt coating process for designing a lipid based controlled release drug delivery system for highly aqueous soluble drugs.

Hot-melt coating process (HMCP) was applied to develop a lipid based oral controlled release matrix system (tablet) to deliver highly aqueous soluble drugs using paracetamol as a model drug. Granules prepared from paracetamol and particular filler were coated with different levels of lipid and then compressed into tablets to get controlled/sustained delivery of the drug over an optimum period. Process parameters were optimized with particular focus on fluidization pattern during HMCP proposing a 'design space' with 'Quality by Design' (QbD) concept in mind. The results demonstrated that the granule composition influenced the drug release pattern, and the rate of release could be manipulated by varying the amount of lipid in the formulation. The in vitro release profile of the drug was pH-independent and the most promising release profile was obtained from tablets prepared from granules with the water-soluble filler, lactose, and coated at 9% (w/w) level with a lipid, glyceryl behanate. In vivo plasma profiles of the drug were predicted from the in vitro release profile data by convolution analysis which confirmed that the lactose based formulation with 9% (w/w) lipid coating on the granules would be suitable for controlled delivery of the drug over a period of 12 h making the formulation suitable for highly water soluble drug candidates like paracetamol with twice daily dose regimen. Moreover, the dissolution data adequately fitted into Higuchi model suggesting that the drug release occurred predominantly by diffusion.

Classification of loratadine based on the biopharmaceutics drug classification concept and possible in vitro-in vivo correlation.

Loratadine was studied both in vitro and in vivo (in healthy humans) to classify it according to the Biopharmaceutics Classification System (BCS) in order to gain more understanding of the reasons for its highly variable nature with respect to plasma time profiles, and to determine the most appropriate dissolution test conditions for in vitro assessment of the release profile of the drug from solid dose forms. Based on the solubility of loratadine determined under various pH conditions and its permeability through Caco-2 monolayers, loratadine was classified as a Class II drug. Plasma profiles were predicted by convolution analysis using dissolution profiles obtained under various pH and hydrodynamic conditions as the input function and plasma time data obtained from a syrup formulation as the weighting function. The predicted profiles based on dissolution studies done at gastric pH values were in reasonable agreement with the mean bio-data suggesting dissolution testing should be done at gastric pH values. However, the bio-data were highly variable and it is suggested this may be due, at least in part, to high individual gastric pH variability and dissolution occurring in the intestine on some occasions, and therefore, dissolution testing should also be done in simulated intestinal fluid.