Mucoadhesive Properties of Thiolated Pectin-Based Pellets Prepared by Extrusion-Spheronization Technique

Thiol-Ene Click Reaction in Constructing Liquid Separation Membranes for Water Treatment

In the evolving landscape of water treatment, membrane technology has ascended to an instrumental role, underscored by its unmatched efficacy and ubiquity. Diverse synthesis and modification techniques are employed to fabricate state-of-the-art liquid separation membranes. Click reactions, distinguished by their rapid kinetics, minimal byproduct generation, and simple reaction condition, emerge as a potent paradigm for devising eco-functional materials. While the metal-free thiol-ene click reaction is acknowledged as a viable approach for membrane material innovation, a systematic elucidation of its applicability in liquid separation membrane development remains conspicuously absent. This review elucidates the pre-functionalization strategies of substrate materials tailored for thiol-ene reactions, notably highlighting thiolation and introducing unsaturated moieties. The consequential implications of thiol-ene reactions on membrane properties-including trade-off effect, surface wettability, and antifouling property-are discussed. The application of thiol-ene reaction in fabricating various liquid separation membranes for different water treatment processes, including wastewater treatment, oil/water separation, and ion separation, are reviewed. Finally, the prospects of thiol-ene reaction in designing novel liquid separation membrane, including pre-functionalization, products prediction, and solute-solute separation membrane, are proposed. This review endeavors to furnish invaluable insights, paving the way for expanding the horizons of thiol-ene reaction application in liquid separation membrane fabrication.

A Window for Enhanced Oral Delivery of Therapeutics via Lipid Nanoparticles

Oral administration of dosage forms is convenient and beneficial in several respects. Lipid nanoparticulate dosage forms have emerged as a useful carrier system in deploying low solubility drugs systemically, particularly class II, III, and IV drugs of the Biopharmaceutics Classification System. Like other nanoparticulate delivery systems, their low size-to-volume ratio facilitates uptake by phagocytosis. Lipid nanoparticles also provide scope for high drug loading and extended-release capability, ensuring diminished systemic side effects and improved pharmacokinetics. However, rapid gastrointestinal (GI) clearance of particulate delivery systems impedes efficient uptake across the mucosa. Mucoadhesion of dosage forms to the GI mucosa results in longer transit times due to interactions between the former and mucus. Delayed transit times facilitate transfer of the dosage form across the mucosa. In this regard, a balance between mucoadhesion and mucopenetration guarantees optimal systemic transfer. Furthermore, the interplay between GI anatomy and physiology is key to ensuring efficient systemic uptake. This review captures salient anatomical and physiological features of the GI tract and how these can be exploited for maximal systemic delivery of lipid nanoparticles. Materials used to impart mucoadhesion and examples of successful mucoadhesive lipid nanoformulations are highlighted in this review.

Optimization and evaluation of Lisinopril mucoadhesive sustained release matrix pellets: In-vitro and ex-vivo studies

Lisinopril (LIS) is antihypertensive drug, classified as a class III drug with high water solubility and low permeability. To overcome the low permeability, 3² factorial designs aimed to formulate LIS as a sustained-release (LIS-SR) matrix pellet by extrusion/spheronization. Matrix pellets were composed of wet mass containing Avicel® and polymeric matrix polymers (sodium alginate (SA) and chitosan (CS)). Evaluation of the effect of two independent variables, matrix-forming units (SA and CS) on mean line torque, on pellet size, dissolution rate after 6 h, and mucoadhesion strength of the pellets were assessed using Statgraphics software. The tested formulations (F1-F9) showed that mean line torque ranged from 1.583 to 0.461 Nm, with LIS content in the LIS-SR pellets ranged from 87.9 to 103%, sizes varied from 1906 to 1404 µm and high percentages of drug released from pellets formulations (68.48 to 74.18 %), while the mean zeta potential value of mucoadhesive range from -17.5 to -22.9 mV. The selection of optimized formulation must have the following desirability: maximum peak torque, maximum pellets' particle size, and minimum % LIS release after 6hr. LIS optimized sustained release pellet formula composed of 2,159 % SA and 0.357 % CS was chosen as optimized formula. It's showed a 1.055 Nm mean line torque was responsible for the increased pellet size to 1830.8 μm with decreased release rate 56.2 % after 6 hr, and -20.33 mV average mucin zeta potential. Ex-vivo mucoadhesion studies revealed that that the optimize formulation, exhibited excellent mucoadhesive properties, after 1 h, about 73% of the pellets were still attached to the mucus membrane. Additionally, ex-vivo permeation determination of LIS from the optimized LIS-SR formulation was found to be significantly higher (1.7-folds) as compared to free LIS. In conclusion: LIS-SR matrix pellets, prepared with an extrusion/spheronization have desirable excellent characteristics in-vitro and ex-vivo sustained-release pellet formulation of LIS-SR was able to sustain the release of LIS for up to 8 h.

Pectin Microspheres: Synthesis Methods, Properties, and Their Multidisciplinary Applications

There is great contemporary interest in using cleaner technologies through green chemistry and utilizing biopolymers as raw material. Pectin is found on plant cell walls, and it is commonly extracted from fruit shells, mostly apples or citrus fruits. Pectin has applications in many areas of commercial relevance; for this reason, it is possible to find available information about novel methods to transform pectin and pursuing enhanced features, with the structuring of biopolymer microspheres being highly cited to enhance its activity. The structuring of polymers is a technique that has been growing in recent decades, due to its potential for diverse applications in various fields of science and technology. Several techniques are used for the synthesis of microspheres, such as ionotropic gelation, extrusion, aerosol drying, or emulsions, with the latter being the most commonly used method based on its reproducibility and simplicity. The most cited applications are in drug delivery, especially for the treatment of colon diseases and digestive-tract-related issues. In the industrial field, it is used for protecting encapsulated compounds; moreover, the environmental applications mainly include the bioremediation of toxic substances. However, there are still many possibilities for expanding the use of this biopolymer in the environmental field.

Quality aspects in the development of pelletized dosage forms

The aim of this work was to identify and collate the major common challenges that arise during pellet development. These challenges focus on aspects right from raw material properties until the final drying process of the pelletization. The challenges associated with the particle size of drug and excipients, physicochemical properties, drug excipient interaction and the effect of type/grade and amount of raw material on the pellet properties are covered in this review. Technological and process related challenges within the commonly used pelletization techniques such as extrusion-spheronization, hot-melt extrusion and layering techniques are also emphasized. The paper likewise gives an insight to the possible ways of addressing the quality of pellets during development.

Enhanced nail delivery of voriconazole-loaded nanomicelles by thioglycolic acid pretreatment: A study of protein dynamics and disulfide bond rupture

This work aimed to select an effective penetration enhancer (PE) for nail pretreatment, develop voriconazole (VOR)-loaded nanomicelles, and evaluate their ability to deliver VOR to the nail. A complete analysis of nail protein dynamics, bond rupture, and microstructure was performed. Alternative methods as electron paramagnetic resonance (EPR) and the Ellman's reagent (DTNB) assay were also evaluated. Nanomicelles were produced and characterized. The PE hydrated the hooves, following the order: urea ≈ cysteine ≈ glycolic acid < thioglycolic acid (TGA) < NaOH. SEM images and methylene blue assay showed enlarged pores and roughness of porcine hooves after incubation with NaOH and TGA. EPR was demonstrated to be the most sensitive technique. DTNB assay quantified higher thiol groups for samples treated with TGA (p < 0.05). A stratigraphic analysis with Raman spectroscopy demonstrated that hooves treated with TGA presented a higher SH/SS ratio at the edges, affecting protein secondary structure. In vitro permeation studies demonstrated significant VOR permeation (29.44 ± 6.13 µg/cm²), 10-fold higher than previous studies with lipid nanoparticles. After TGA pretreatment, VOR permeation was further enhanced (3-fold). TGA pretreatment followed by VOR-loaded nanomicelles demonstrates a promising approach for onychomycosis treatment. The novel methods for protein analysis were straightforward and helpful.

Synthesis and characterization of Chitosan-Catechol conjugates: Development and in vitro, in silico and in vivo evaluation of mucoadhesive pellets of lafutidine

Present study was aimed to synthesize and characterize Chitosan-Catechol conjugates and to design and develop mucoadhesive pellets loaded with lafutidine. SEM images indicated the presence of fibrous structures responsible for enhanced mucoadhesive potential of Chitosan-Catechol conjugates. Thermodynamic stability and amorphous nature of conjugates was confirmed by DSC and XRD studies respectively. Rheological studies were used to evaluate polymer mucin interactions wherein strong interactions between Chitosan-Catechol conjugate and mucin was observed in comparison to pristine chitosan and mucin. The mucoadhesion potential of Chitosan-Catechol (Cht-C) versus Chitosan (Cht) was assessed in silico using molecular mechanics simulations and the results obtained were compared with the in vitro and ex vivo results. Cht-C/mucin demonstrated much higher energy stabilization (∆E ≈ −65 kcal/mol) as compared to Cht/mucin molecular complex. Lafutidine-loaded pellets were prepared from Chitosan (LPC) and Chitosan-Catechol conjugates (LPCC) and were evaluated for various physical properties viz. flow, circularity, roundness, friability, drug content, particle size and percent mucoadhesion. In vitro drug release studies on LPC and LPCC pellets were performed for computing t50%, t90% and mean dissolution time. The values of release exponent from Korsmeyer-Peppas model was reported to be 0.443 and 0.759 for LPC and LPCC pellets suggesting Fickian and non-Fickian mechanism representing drug release, respectively. In vivo results depicted significant controlled release and enhanced residence of the drug after being released from the chitosan-catechol coated pellets. Chitosan-Catechol conjugates were found to be a promising biooadhesive polymer for the development of various mucoadhesive formulations.

The preparation of lipid-based drug delivery system using melt extrusion

Melt extrusion of lipids is versatile with high applicability in the pharmaceutical industry. The formulations prepared can be easily customized depending on the requirements, and have the potential to open a window on personalized medicine.

Thiolation of Biopolymers for Developing Drug Delivery Systems with Enhanced Mechanical and Mucoadhesive Properties: A Review

Biopolymers are extensively used for developing drug delivery systems as they are easily available, economical, readily modified, nontoxic, biodegradable and biocompatible. Thiolation is a well reported approach for enhancing mucoadhesive and mechanical properties of polymers. In the present review article, for the modification of biopolymers different thiolation methods and evaluation/characterization techniques have been discussed in detail. Reported literature on thiolated biopolymers with enhanced mechanical and mucoadhesive properties has been presented conspicuously in text as well as in tabular form. Patents filed by researchers on thiolated polymers have also been presented. In conclusion, thiolation is an easily reproducible and efficient method for customization of mucoadhesive and mechanical properties of biopolymers for drug delivery applications.

Thiolated polymers: Bioinspired polymers utilizing one of the most important bridging structures in nature

Thiolated polymers designated "thiomers" are obtained by covalent attachment of thiol functionalities on the polymeric backbone of polymers. In 1998 these polymers were first described as mucoadhesive and in situ gelling compounds forming disulfide bonds with cysteine-rich substructures of mucus glycoproteins and crosslinking through inter- and intrachain disulfide bond formation. In the following, it was shown that thiomers are able to form disulfides with keratins and membrane-associated proteins exhibiting also cysteine-rich substructures. Furthermore, permeation enhancing, enzyme inhibiting and efflux pump inhibiting properties were demonstrated. Because of these capabilities thiomers are promising tools for drug delivery guaranteeing a strongly prolonged residence time as well as sustained release on mucosal membranes. Apart from that, thiomers are used as drugs per se. In particular, for treatment of dry eye syndrome various thiolated polymers are in development and a first product has already reached the market. Within this review an overview about the thiomer-technology and its potential for different applications is provided discussing especially the outcome of studies in non-rodent animal models and that of numerous clinical trials. Moreover, an overview on product developments is given.

Challenges and Recent Progress in Oral Drug Delivery Systems for Biopharmaceuticals

Routes of drug administration and the corresponding physicochemical characteristics of a given route play significant roles in therapeutic efficacy and short term/long term biological effects. Each delivery method has favorable aspects and limitations, each requiring a specific delivery vehicles design. Among various routes, oral delivery has been recognized as the most attractive method, mainly due to its potential for solid formulations with long shelf life, sustained delivery, ease of administration and intensified immune response. At the same time, a few challenges exist in oral delivery, which have been the main research focus in the field in the past few years. The present work concisely reviews different administration routes as well as the advantages and disadvantages of each method, highlighting why oral delivery is currently the most promising approach. Subsequently, the present work discusses the main obstacles for oral systems and explains the most recent solutions proposed to deal with each issue.