Doxycycline and Monocaprin In Situ Hydrogel: Effect on Stability, Mucoadhesion and Texture Analysis and In Vitro Release

Gels as Promising Delivery Systems: Physicochemical Property Characterization and Recent Applications

Gels constitute a versatile class of materials with considerable potential for applications in both technical and medical domains. Physicochemical property characterization is a critical evaluation method for gels. Common characterization techniques include pH measurement, structural analysis, mechanical property assessment, rheological analysis, and phase transition studies, among others. While numerous research articles report characterization results, few reviews comprehensively summarize the appropriate numerical ranges for these properties. This lack of standardization complicates harmonized evaluation methods and hinders direct comparisons between different gels. To address this gap, it is essential to systematically investigate characterization methods and analyze data from the extensive body of literature on gels. In this review, we provide a comprehensive summary of general characterization methods and present a detailed analysis of gel characterization data to support future research and promote standardized evaluation protocols.

Synthesis and biological applications of nanocomposite hydrogels based on the methacrylation of hydroxypropyl methylcellulose and lignin loaded with alpha-pinene

Oral conditions, such as recurrent aphthous stomatitis, are chronic inflammatory disorders that significantly affect the life quality. This study aims to develop a novel buccal mucoadhesive based on methacrylate hydroxypropyl methylcellulose (M-HPMC) and methacrylate lignin (M-SLS) encapsulated with nanostructured lipid carriers (NLCs) for controlled release of alpha-pinene (α-pinene). NLCs with particle sizes of 152 ± 3 nm were prepared by using stearic acid and oleic acid as solid and liquid lipids, respectively. Following the successful synthesis of M-HPMC and M-SLS, various concentrations of α-pinene loaded NLCs (0, 18, 38, and 50 wt%) were encapsulated in M-HPMC/M-SLS hydrogel. It was demonstrated that the physiological and mechanical performances of hydrogels were changed, depending on the NLC content. Remarkably, the incorporation of 18 wt% NLC improved the compressive strength (143 ± 14 kPa) and toughness (17 ± 1 kJ/m3) of M-HPMC/M-SLS hydrogel. This nanocomposite hydrogel considerably decreased dissipated energy from 1.64 kJ/m3 to 0.99 kJ/m3, after a five-cycle compression test. The nanocomposite hydrogel exhibited controlled α-pinene release for up to 96 h which could significantly improve the antioxidant activity of M-HPMC/M-SLS matrix. Moreover, the reinforcing M-HPMC/M-SLS hydrogel with α-pinene-loaded NLCs resulted in increased adhesive strength (113.5 ± 7.5 kPa) to bovine buccal mucosa and cytocompatibility in contact with fibroblasts.

Enhancing mucoadhesion: Exploring rheological parameters and texture profile in starch solutions, with emphasis on micro-nanofiber influence

This comprehensive analysis explores the rheological parameters and texture profile analysis (TPA) to effect starch solutions for mucoadhesion and assess the impact of micro-nanofibers (MNFs) on these parameters. The surface chemistry of all six samples was examined through the Fourier transform infrared (FTIR) technique. The spectrum of FTIR was recorded in the range of 500-4000 cm-1. The viscosity of different pHs (2-11) and temperatures (20-70 °C) of verious starches, potato, corn, and rice, decreased with the increasing of shear rate, exhibiting shear thinning behavior, which conformed to pseudoplastic fluid.The combination of chitosan and collagen MNFs significantly changed rheological properties, and the sample with the addtion of 1500 µL CC-MNF exhibited a greater viscosity of 59.8 mPa·s at a shear rate of 1.49 s-1. Potato starch emerged as a strong candidate for mucoadhesion due to its low hardness (4.62 ± 0.31 N), high adhesion (0.0322 ± 0.0053 mJ), cohesiveness (0.37 ± 0.03 Ratio), low chewiness (0.66 ± 0.12 mJ), and gumminess (1.69 ± 0.23 N). The inclusion of MNFs, especially collagen/chitosan MNFs showed the potential to further enhance adhesion.

Characterization of Prototype Gummy Formulations Provides Insight into Setting Quality Standards

Gummy formulations are considered suitable alternatives to traditional oral dosage forms like tablets and capsules due to their merits that include chewability, softness/flexibility, improved drug release, administration without water, appealing organoleptic properties, better patient compliance, easy preparation and usefulness for persons of different ages (e.g. children). Though there is increasing interest in gummy formulations containing drugs, measurable parameters, and specification limits for evaluating their quality are scarce. Quality check forms an essential part of the pharmaceutical development process because drug products must be distributed as consistently stable, safe, and therapeutically effective entities. Consequently, some quality parameters that could contribute to the overall performance of typical gummy formulations were investigated employing six brands of non-medicinal gummies as specimens. Accordingly, key physicochemical and micromechanical characteristics namely adhesiveness (0.009 - 0.028 mJ), adhesive force (0.009 - 0.055 N), chewiness (2.780 - 6.753 N), cohesiveness (0.910 - 0.990), hardness (2.984 - 7.453 N), springiness (0.960 - 1.000), and resilience (0.388 - 0.572), matrix firmness - compression load (2.653 - 6.753 N) and work done (3.288 - 6.829 mJ), rupture (5.315 - 29.016 N), moisture content (< 5%), weight uniformity (< 2.5 g; < 7.5% deviation), and intraoral dissolution pH (≥ 3.5 ≤ 6.8) were quantified to identify measures that may potentially function as specification limits and serve as prospective reference points for evaluating the quality of gummy formulations. Findings from this work contribute to ongoing efforts to standardize the quality control strategies for gummy formulations, particularly those intended for oral drug delivery.

A comprehensive review of medium chain monoglycerides on metabolic pathways, nutritional and functional properties, nanotechnology formulations and applications in food system

A large and growing body of literature has investigated the broad antibacterial spectrum and strong synergistic antimicrobial activity of medium chain monoglycerides (MCMs) have been widely investigated. Recently, more and more researches have focused on the regulation of MCMs on metabolic health and gut microbiota both in vivo and in vitro. The current review summarizes the digestion, absorption and metabolism of MCMs. Subsequently, it focuses on the functional and nutritional properties of MCMs, including the antibacterial and antiviral characteristics, the modulation of metabolic balance, the regulation of gut microbiota, and the improvement in intestinal health. Additionally, we discuss the most recent developments and application of MCMs using nanotechnologies in food industry, poultry and pharmaceutical industry. Additionally, we analyze recent application examples of MCMs and their nanotechnology formation used in food. The development of nanotechnology platforms facilitating molecular encapsulation and functional presentation contribute to the application of hydrophobic fatty acids and monoglycerides in food preservation and their antibacterial effectiveness. This study emphasizes the metabolic mechanisms and biological activity of MCMs by summarizing the prevailing state of knowledge on this topic, as well as providing insights into prospective techniques for developing the beneficial applications of MCMs to realize the industrialized production.

Liquid-like Oral Sustained-Release System Based on Acid-Sensitive in situ Hydrogel for Alleviate Gastrointestinal Side Effects of Indobufen

Commonly, most oral non-steroidal anti-inflammatory drugs (NSAIDs) have known gastric adverse reactions due to their long-term and high dose administration. In this study, a novel liquid sustained-release system based on multiple-unit in situ hydrogel beads was designed to address this issue. The system is composed of sodium alginate (SA), gellan gum (GG), zinc oxide (ZnO), and magnesium oxide (MgO). Furthermore, indobufen was loaded into the system to evaluate its gastric mucosal protection effect. This effect can be attributed to the topical antacid, pepsin inhibition, and sustained drug release properties of the system. It was proven that the stored solid gel system could undergo a "solid to liquid" transition after shaking. Once swallowed, the liquid gel could disperse well in the stomach as hydrogel beads. Then, the "liquid to solid" gelation occurred from the exterior to interior of each multiple-unit gel bead, triggered by the release of Zn2+ and Mg2+ from neutralization reactions. The formed gel demonstrated mild antacid effect that lasted for 3 hours and 66.3% pepsin inhibition in vivo. Moreover, the rats treated with the indobufen gel system showed a drug plasma concentration versus time curve with less fluctuation compared to the rats treated with the marketed preparation (YinDuo®) group. The gel system also exhibited an extended Tmax (6.50 hours) and reduced Cmax (52.87 μg/mL). Additionally, the gastric mucosal protection of the gel system was verified using three types of peptic gastric ulcer models. These findings suggested that this multiple-unit in situ gel could be a potential oral liquid sustained release delivery system for NSAIDs.

Polymeric in situ forming depots for long-acting drug delivery systems

Polymeric in situ forming depots have emerged as highly promising drug delivery systems for long-acting applications. Their effectiveness is attributed to essential characteristics such as biocompatibility, biodegradability, and the ability to form a stable gel or solid upon injection. Moreover, they provide added versatility by complementing existing polymeric drug delivery systems like micro- and nanoparticles. The formulation's low viscosity facilitates manufacturing unit operations and enhances delivery efficiency, as it can be easily administered via hypodermic needles. The release mechanism of drugs from these systems can be predetermined using various functional polymers. To enable unique depot design, numerous strategies involving physiological and chemical stimuli have been explored. Important assessment criteria for in situ forming depots include biocompatibility, gel strength and syringeability, texture, biodegradation, release profile, and sterility. This review focuses on the fabrication approaches, key evaluation parameters, and pharmaceutical applications of in situ forming depots, considering perspectives from academia and industry. Additionally, insights about the future prospects of this technology are discussed.

In Vitro and In Vivo Characterisation of a Mucoadhesive Buccal Film Loaded with Doxycycline Hyclate for Topical Application in Periodontitis

Mucoadhesive films loaded with doxycycline hyclate (Doxy Hyc), consisting of mixtures of hydroxypropylmethyl cellulose (HPMC) E3, K4 and polyacrylic acid (Carbopol 940), were prepared by casting method, aiming to design a formulation intended for application in the oral cavity. The obtained film formulations exhibited a Doxy Hyc content between 7.52 ± 0.42 and 7.83 ± 0.41%, which had adequate mechanical properties for application in the oral cavity and pH values in the tolerance range. The x-ray diffraction studies highlighted the amorphisation of Doxy Hyc in the preparation process and the antibiotic particles present on the surface of the films, identified in the TEM images, which ensured a burst release effect in the first 15 min of the in vitro dissolution studies, after which Doxy Hyc was released by diffusion, the data presenting a good correlation with the Peppas model, n < 0.5. The formulation F1, consisting of HPMC K4 combined with C940 in a ratio of 5:3, the most performing in vitro, was tested in vivo in experimentally-induced periodontitis and demonstrated its effectiveness in improving the clinical parameters and reducing the salivary levels of matrix metalloproteinase-8 (MMP-8). The prepared Doxy Hyc loaded mucoadhesive buccal film could be used as an adjuvant for the local treatment of periodontitis, ensuring prolonged release of the antibiotic after topical application.

Hydrogels for modified-release drug delivery systems

Hydrogels for the modified-release drug delivery systems is a continuously growing area of interest for the pharmaceutical industry. According to the global market, the use of polymers in this area is projected to reach $31.4 million by 2027. This review discusses the recent advances and perspectives of hydrogel in drug delivery systems for oral, parenteral, nasal, topical, and ophthalmic. The search strategy did in January 2021, and it conducted an extensive database to identify studies published from January 2010 to December 2020.We described the main characteristic of the polymers to obtain an ideal hydrogel for a specific route of administration and the formulations that was a highlight in the literature. It concluded that the hydrogels are a set useful to decrease the number of doses, side effects, promote adhesion of patient and enhances the bioavailability of the drugs improving the safety and efficacy of the treatment.

3D printed bioinspired scaffolds integrating doxycycline nanoparticles: Customizable implants for in vivo osteoregeneration

3D printing has revolutionized pharmaceutical research, with applications encompassing tissue regeneration and drug delivery. Adopting 3D printing for pharmaceutical drug delivery personalization via nanoparticle-reinforced hydrogel scaffolds promises great regenerative potential. Herein, we engineered novel core/shell, bio-inspired, drug-loaded polymeric hydrogel scaffolds for pharmaceutically personalized drug delivery and superior osteoregeneration. Scaffolds were developed using biopolymeric blends of gelatin, polyvinyl alcohol and hyaluronic acid and integrated with composite doxycycline/hydroxyapatite/polycaprolactone nanoparticles (DX/HAp/PCL) innovatively via 3D printing. The developed scaffolds were optimized for swelling pattern and in-vitro drug release through tailoring the biphasic microstructure and wet/dry state to attain various pharmaceutical personalization platforms. Freeze-dried scaffolds with nanoparticles reinforcing the core phase (DX/HAp/PCL-LCS-FD) demonstrated favorably controlled swelling, preserved structural integrity and controlled drug release over 28 days. DX/HAp/PCL-LCS-FD featured double-ranged pore size (90.4 ± 3.9 and 196.6 ± 38.8 µm for shell and core phases, respectively), interconnected porosity and superior mechanical stiffness (74.5 ± 6.8 kPa) for osteogenic functionality. Cell spreading analysis, computed tomography and histomorphometry in a rabbit tibial model confirmed osteoconduction, bioresorption, immune tolerance and bone regenerative potential of the original scaffolds, affording complete defect healing with bone tissue. Our findings suggest that the developed platforms promise prominent local drug delivery and bone regeneration.

An overview of PLGA in-situ forming implants based on solvent exchange technique: effect of formulation components and characterization

As a result of the low oral bioavailability of several drugs, there is a renewed interest for parenteral administration to target their absorption directly into the blood bypassing the long gastrointestinal route and hepatic metabolism. In order to address the potential side effects of frequent injections, sustained release systems are the most popular approaches for achieving controlled long-acting drug delivery. Injectable in-situ forming implants (ISFIs) have gained greater popularity in comparison to other sustained systems. Their significant positive aspects are attributed to easier production, acceptable administration route, reduced dosing frequency and patient compliance achievement. ISFI systems, comprising biodegradable polymers such as poly (lactide-co-glycolide) (PLGA) based on solvent exchange mechanisms, are emerged as liquid formulations that develop solid or semisolid depots after injection and deliver drugs over extended periods. The drug release from ISFI systems is generally characterized by an initial burst during the matrix solidification, followed by diffusion processes and finally polymeric degradation and erosion. The choice of suitable solvent with satisfactory viscosity, miscibility and biocompatibility along with considerable PLGA hydrophobicity and molecular weights is fundamental for optimizing the drug release. This overview gives a particular emphasis on evaluations and the wide ranges of requirements needed to achieve reasonable physicochemical characteristics of ISFIs.