Investigation of the mucoadhesivity, swelling, and drug release mechanisms of indomethacin buccal tablets: effect of formulation variables

Nanoparticle-Mediated Strategies for Enhanced Drug Penetration and Retention in the Airway Mucosa

Airway mucus is a complex viscoelastic gel composed mainly of water, glycoproteins, lipids, enzymes, minerals, etc. Among them, glycoproteins are the main factors determining mucus's gel-like rheology. Airway mucus forms a protective barrier by secreting mucin, which represents a barrier for absorption, especially for more lipophilic drugs. It rapidly removes drugs from the airway through the physiological mucus clearance mechanism so drugs cannot remain in the lungs or reach the airway epithelial tissue for a long time. Significant progress has been made in enhancing drug lung deposition recently, but strategies are still needed to help drugs break through the lung mucosal barrier. Based on the physiopathological mechanisms of airway mucus, this paper reviews and summarizes strategies to enhance drug penetration and retention in the airway mucosa mediated by nano-delivery systems, including mucosal permeation systems, mucosal adhesion systems, and enzyme-modified delivery systems. On this basis, the potential and challenges of nano-delivery systems for improving airway mucus clearance are revealed. New ideas and approaches are provided for designing novel nano-delivery systems that effectively improve drug retention and penetration in the airway mucus layer.

Timolol-loaded ethosomes for ophthalmic delivery: Reduction of high intraocular pressure in vivo

The beta-adrenoceptor blocker timolol maleate (TML) is a commonly used pharmaceutical agent for the management of glaucoma. Conventional eye drops have limitations due to biological or pharmaceutical factors. Therefore, TML-loaded ethosomes have been designed to mitigate these restrictions and give a viable solution for reducing elevated intraocular pressure (IOP). The ethosomes were prepared using the thin film hydration method. Integrating the Box-Behnken experimental strategy, the optimal formulation was identified. The physicochemical characterization studies were performed on the optimal formulation. Then, in vitro release and ex vivo permeation studies were conducted. The irritation assessment was also carried out with Hen's Egg Test-Chorioallantoic Membrane model (HET-CAM), and in vivo evaluation of the IOP lowering effect was also performed on rats. The physicochemical characterization studies demonstrated that the components of the formulation were compatible with each other. The particle size, zeta potential, and encapsulation efficiency (EE%) were found as 88.23 ± 1.25 nm, -28.7 ± 2.03 mV, and 89.73 ± 0.42 %, respectively. The in vitro drug release mechanism was found as Korsmeyer-Peppas kinetics (R²=0.9923). The HET-CAM findings verified the formulation's eligibility for biological applications. The IOP measurements revealed no statistical difference (p>0.05) between the once-a-day application of the optimal formulation and the three-times-a-day application of the conventional eye drop. A similar pharmacological response was observed at lowered application frequencies. Therefore, it was concluded that the novel TML-loaded ethosomes could be a safe and efficient alternative for glaucoma treatment.

Facile fabrication of semi-IPN hydrogel adsorbent based on quaternary cellulose via amino-anhydride click reaction in water

Clean and safe water resources play a key role in environmental safety and human health. Recently, hydrogels have attracted extensive attention due to their non-toxicity, controllable performance, and high adsorption. Herein, a semi- interpenetrating network hydrogel (semi-IPN-Gel) adsorbent based on quaternary cellulose (QC) was prepared by the amino-anhydride click reaction between maleic anhydride copolymer and polyacrylamine hydrochloride (PAH), and its adsorption properties for Eosin Y were studied. First, a binary copolymer (PAM) of acrylamide and maleic anhydride was synthesized by free radical polymerization. Then, the PAM, QC and PAH were dissolved in water, and the pH of the solution was adjusted to alkaline. Semi-IPN-Gel was successfully prepared by fast anhydride-amino click reaction. The preparation conditions of hydrogels were optimized by single-factor experiments. Finally, taking Eosin Y as a model pollutant, the adsorption performance of Eosin Y was studied. The factors influencing the adsorption capacity of the absorbents such as initial concentration of the Eosin Y, temperature, the amount of absorbent, ionic strength and pH of the Eosin Y solutions were investigated. And adsorption data were analyzed via the kinetic model and the isothermal model, indicating that the adsorption process of the hydrogel is a single layer chemisorption process.

Interactions of Crosslinked Polyacrylic Acid Polyelectrolyte Gels with Nonionic and Ionic Surfactants

The morphology and stability of surfactant-loaded polyelectrolyte gels are of great interest for a variety of personal care, cosmetic, and pharmaceutical products. However, the mechanisms of surfactant interactions with gel-forming polymers are poorly understood and experimentally challenging. The aim of this work is to explore in silico the specifics of surfactant absorption within polyelectrolyte gels drawing on the examples of typical non-ionic octaethylene glycol monooctyl ether (C₈E₈) and anionic sodium dodecyl sulfate (SDS) surfactants and polyacrylic acid modified with hydrophobic sidechains mimicking the practically important Carbopol polymer. Using the systematically parameterized coarse-grained dissipative particle dynamics models, we generate and characterize the equilibrium conformations and swelling of the polymer films in aqueous solutions with the surfactant concentrations varied up to the critical micelle concentration (cmc). We discover the striking difference in interactions of Carbopol-like polymers with nonionic and ionic surfactants under mildly acidic conditions. The sorption of C₈E₈ within the polymer film is found substantial. As the surfactant concentration increases, the polymer film swells and, close to cmc, becomes unstable due to the formation and growth of water pockets filled with surfactant micelles. Sorption of SDS at the same bulk concentrations is found much lower, with only about 1% of surfactant mass fraction achieved at cmc. As the SDS concentration increases further, a lamellae structure is formed within the film, which remains stable. Reduced swelling and higher stability indicate better prospects of using SDS-type surfactants with Carbopol-based gels in formulations for detergents and personal care products.

Development and optimization of tibezonium iodide and lignocaine hydrochloride containing novel mucoadhesive buccal tablets: A pharmacokinetic investigation among healthy humans

OBJECTIVE

It is clinically important to deliver sustained-release mucoadhesive dosage of local anesthetic and antimicrobial agent for pain control. The current study aimed to develop and evaluate chitosan (CHI) based buccal mucoadhesive delivery for local release of tibezonium iodide (TBN) and lignocaine hydrochloride (LGN).

METHODS

Direct compression technique was employed, aided by other mucoadhesive polymers like hydroxypropylmethylcellulose (HPMC) and sodium alginate (SA) and evaluated for physicochemical and in vivo character.

RESULTS

Fourier transform infrared spectral analysis (FTIR), powdered X-ray diffraction (XRPD), and differential scanning calorimetry (DSC) absence of physical interaction between ingredients. The physical parameters complied with USP specifications for all formulations. Optimum swellability (551.9%) was offered from formulation TL15, containing 30% SA. Highest ex vivo mucoadhesive strength (24.79 g) and time (18.39 h) was found with TL8. Formulation TL8 also exhibited maximum in vivo residence time (11.37 h). Almost complete drug release at 6 h was possessed by formulation TL5 (HPMC and CHI, 20% each) for TBN (99.98%) and LGN (99.06%). The optimized formulation TL5 exhibited dosage stability up to 6 months at 75% relative humidity and retained drug contents. TL5 was well tolerated by the volunteers with no inflammation, pain or irritation found. Almost 73% of volunteers reported an increase in salivary secretion. The first-order salivary C_max of TBN and LGN were found as 16.02 and 7.80 µg/mL within 4 h, respectively.

CONCLUSION

Therefore, the sustained release mucoadhesive dosage form of TBN and LGN can be an effective and alternative option to conventional delivery.

Mucoadhesion and Mucopenetration of Cannabidiol (CBD)-Loaded Mesoporous Carrier Systems for Buccal Drug Delivery

Transmucosal drug delivery represents a promising noninvasive option when drugs are employed which have a low oral bioavailability like CBD. However, this concept can only be successful as long as the formulation provides sufficient buccal retention and mucosal penetration. In this study, mucoadhesive carrier systems were evaluated consisting of CBD-loaded silica (Aeroperl 300) carriers, mucoadhesive polymers (Hypromellose (HPMC), chitosan and carbomer) and propylene glycol as a penetration enhancer. Mucoadhesive effect, drug release and penetration ability were evaluated for each carrier system. The results show that the addition of HPMC and carbomer substantially improve mucoadhesion compared to pure CBD, with an increase of 16-fold and 20-fold, respectively. However, due to their strong swelling, HPMC and carbomer hinder the penetration of CBD and rely on co-administration of propylene glycol as an enhancer to achieve sufficient mucosal absorption. Chitosan, on the other hand, achieves an 8-fold increase in mucoadhesion and enhances the amount of CBD absorbed by three times compared to pure CBD. Thus, chitosan represents a promising polymer to combine both effects. Considering the results, the development of silica-based buccal drug delivery systems is a promising approach for the effective delivery of CBD.