Lysozyme Mucoadhesive Tablets Obtained by Freeze-Drying

Starch-Based Polysaccharide Systems with Bioactive Substances: Physicochemical and Wettability Characteristics

Polysaccharide-based systems have very good emulsifying and stabilizing properties, and starch plays a leading role. Their modifications should add new quality features to the product to such an extent that preserves the structure-forming properties of native starch. The aim of this manuscript was to examine the physicochemical characteristics of the combinations of starch with phospholipids or lysozymes and determine the effect of starch modification (surface hydrophobization or biological additives) and preparation temperature (before and after gelatinization). Changes in electrokinetic potential (zeta), effective diameter, and size distribution as a function of time were analyzed using the dynamic light scattering and microelectrophoresis techniques. The wettability of starch-coated glass plates before and after modification was checked by the advancing and receding contact angle measurements, as well as the angle hysteresis, using the settle drop method as a complement to profilometry and FTIR. It can be generalized that starch dispersions are more stable than analogous n-alkane/starch emulsions at room and physiological temperatures. On the other hand, the contact angle hysteresis values usually decrease with temperature increase, pointing to a more homogeneous surface, and the hydrophobization effect decreases vs. the thickness of the substrate. Surface hydrophobization of starch carried out using an n-alkane film does not change its bulk properties and leads to improvement of its mechanical and functional properties. The obtained specific starch-based hybrid systems, characterized in detail by switchable wettability, give the possibility to determine the energetic state of the starch surface and understand the strength and specificity of interactions with substances of different polarities in biological processes and their applicability for multidirectional use.

Texture analysis – a versatile tool for pharmaceutical evaluation of solid oral dosage forms

In the past few decades, texture analysis (TA) has gained importance as a valuable method for the characterization of solid oral dosage forms. As a result, an increasing number of scientific publications describe the textural methods that evaluate the extremely diverse category of solid pharmaceutical products. Within the current work, the use of texture analysis in the characterization of solid oral dosage forms is summarised with a focus on the evaluation of intermediate and finished oral pharmaceutical products. Several texture methods are reviewed regarding the applications in mechanical characterization, and mucoadhesion testing, but also in estimating the disintegration time and in vivo specific features of oral dosage forms. As there are no pharmacopoeial standards for pharmaceutical products tested through texture analysis, and there are important differences between reported results due to different experimental conditions, the choice of testing protocol and parameters is challenging. Thereby, this work aims to guide the research scientists and quality assurance professionals involved in different stages of drug development into the selection of optimal texture methodologies depending on the product characteristics and quality control needs.

Development of Crosslinker-Free Polysaccharide-Lysozyme Microspheres for Treatment Enteric Infection

Antibiotic abuse in the conventional treatment of microbial infections, such as inflammatory bowel disease, induces cumulative toxicity and antimicrobial resistance which requires the development of new antibiotics or novel strategies for infection control. Crosslinker-free polysaccharide-lysozyme microspheres were constructed via an electrostatic layer-by-layer self-assembly technique by adjusting the assembly behaviors of carboxymethyl starch (CMS) on lysozyme and subsequently outer cationic chitosan (CS) deposition. The relative enzymatic activity and in vitro release profile of lysozyme under simulated gastric and intestinal fluids were investigated. The highest loading efficiency of the optimized CS/CMS-lysozyme micro-gels reached 84.9% by tailoring CMS/CS content. The mild particle preparation procedure retained relative activity of 107.4% compared with free lysozyme, and successfully enhanced the antibacterial activity against E. coli due to the superposition effect of CS and lysozyme. Additionally, the particle system showed no toxicity to human cells. In vitro digestibility testified that almost 70% was recorded in the simulated intestinal fluid within 6 h. Results demonstrated that the cross-linker-free CS/CMS-lysozyme microspheres could be a promising antibacterial additive for enteric infection treatment due to its highest effective dose (573.08 μg/mL) and fast release at the intestinal tract.

Alginate-based matrix tablets for drug delivery

INTRODUCTION

As a nature-derived polymer with swelling and gelling properties, alginate has found wide biopharma-relevant applications. However, there is comparatively limited attention on alginate in tablet formulations. Therefore, this review aimed to provide an overview of the applications of alginate in solid dosage form formulations.

AREAS COVERED

This review outlines the role of alginate for oral sustained release formulations. For better insights into its application in drug delivery, the mechanisms of drug release from alginate matrices are discussed alongside the alginate inherent properties and drug properties. Specifically, the influence of alginate properties and formulation components on the resultant alginate gel and subsequent drug release is reviewed. Modifications of the alginate to improve its properties in modulating drug release are also discussed.

EXPERT OPINION

Alginate-based matrix tablets is useful for sustaining drug release. As a nature-derived polymer, batch consistency and stability raise some concerns about employing alginate in formulations. Furthermore, the alginate gel properties can be affected by formulation components, pH of the dissolution environment and the tablet matrix micro-environment pH. Conscientious efforts are pivotal to addressing these formulation challenges to increase the utilization of alginate in oral solid dosage forms.

Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art

Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.

Advances in the Prophylaxis of Respiratory Infections by the Nasal and the Oromucosal Route: Relevance to the Fight with the SARS-CoV-2 Pandemic

In this time of COVID-19 pandemic, the strategies for prevention of the infection are a primary concern. Looking more globally on the subject and acknowledging the high degree of misuse of protective face masks from the population, we focused this review on alternative pharmaceutical developments eligible for self-defense against respiratory infections. In particular, the attention herein is directed to the nasal and oromucosal formulations intended to boost the local immunity, neutralize or mechanically “trap” the pathogens at the site of entry (nose or mouth). The current work presents a critical review of the contemporary methods of immune- and chemoprophylaxis and their suitability and applicability in topical mucosal dosage forms for SARS-CoV-2 prophylaxis.

Core of the saliva microbiome: an analysis of the MG-RAST data

Background

Oral microbiota is considered as the second most complex in the human body and its dysbiosis can be responsible for oral diseases. Interactions between the microorganism communities and the host allow establishing the microbiological proles. Identifying the core microbiome is essential to predicting diseases and changes in environmental behavior from microorganisms.

Methods

Projects containing the term “SALIVA”, deposited between 2014 and 2019 were recovered on the MG-RAST portal. Quality (Failed), taxonomic prediction (Unknown and Predicted), species richness (Rarefaction), and species diversity (Alpha) were analyzed according to sequencing approaches (Amplicon sequencing and Shotgun metagenomics). All data were checked for normality and homoscedasticity. Metagenomic projects were compared using the Mann–Whitney U test and Spearman's correlation. Microbiome cores were inferred by Principal Component Analysis. For all statistical tests, p < 0.05 was used.

Results

The study was performed with 3 projects, involving 245 Amplicon and 164 Shotgun metagenome datasets. All comparisons of variables, according to the type of sequencing, showed significant differences, except for the Predicted. In Shotgun metagenomics datasets the highest correlation was between Rarefaction and Failed (r =  − 0.78) and the lowest between Alpha and Unknown (r =  − 0.12). In Amplicon sequencing datasets, the variables Rarefaction and Unknown (r = 0.63) had the highest correlation and the lowest was between Alpha and Predicted (r =  − 0.03). Shotgun metagenomics datasets showed a greater number of genera than Amplicon. Propionibacterium, Lactobacillus, and Prevotella were the most representative genera in Amplicon sequencing. In Shotgun metagenomics, the most representative genera were Escherichia, Chitinophaga, and Acinetobacter.

Conclusions

Core of the salivary microbiome and genera diversity are dependent on the sequencing approaches. Available data suggest that Shotgun metagenomics and Amplicon sequencing have similar sensitivities to detect the taxonomic level investigated, although Shotgun metagenomics allows a deeper analysis of the microorganism diversity. Microbiome studies must consider characteristics and limitations of the sequencing approaches. Were identified 20 genera in the core of saliva microbiome, regardless of the health condition of the host. Some bacteria of the core need further study to better understand their role in the oral cavity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01719-5.

Strategies and formulations of freeze-dried tablets for controlled drug delivery

The freeze-drying process has been particularly attractive for preparing tablets for controlled drug release. Although traditional methods, such as granulation or direct compression methods, have been used in various studies to produce tablets with controlled release, freeze-drying processes have been utilized in certain circumstances due to their distinct advantages. However, overall, further development of these strategies, which started with early studies on orally disintegrating tablets, is still necessary. In this review, the incorporation of different formulations into freeze-dried tablets will be discussed. Moreover, the use of excipients, freeze-drying conditions, formulation reconstitution and tablet structure for optimizing the performance of freeze-dried tablets will be reported, including strategies with nanoformulations and natural materials. Generally, this discussion with potential approaches will benefit further development of freeze-dried tablets containing drugs in the pharmaceutical industry.

Fabrication of Mucoadhesive Buccal Films for Local Administration of Ketoprofen and Lidocaine Hydrochloride by Combining Fused Deposition Modeling and Inkjet Printing

In the area of developing oromucosal drug delivery systems, mucoadhesive buccal films are the most promising formulations for either systemic or local drug delivery. The current study presents the fabrication of buccal films, by combining fused deposition modeling (FDM) and inkjet printing. Hydroxypropyl methylcellulose-based films were fabricated via FDM, containing the non-steroidal anti-inflammatory drug ketoprofen. Unidirectional release properties were achieved, by incorporating an ethyl cellulose-based backing layer. The local anesthetic lidocaine hydrochloride, combined with the permeation enhancer l-menthol, was deposited onto the film by inkjet printing. Physicochemical analysis showed alterations in the characteristics of the films, and the mucoadhesive and mechanical properties were effectively modified, due to the ink deposition on the substrates. The in vitro release data of the active pharmaceutical compounds, as well as the permeation profiles across ex vivo porcine buccal mucosa and filter-grown TR146 cells of human buccal origin, were associated with the presence of the permeation enhancer and the backing layer. The lack of any toxicity of the fabricated films was demonstrated by the MTT viability assay. This proof-of-concept study provides an alternative formulation approach of mucoadhesive buccal films, intended for the treatment of local oromucosal diseases or systemic drug delivery.

Mucoadhesive Vaginal Discs based on Cyclodextrin and Surfactants for the Controlled Release of Antiretroviral Drugs to Prevent the Sexual Transmission of HIV

The strategies for developing vaginal microbicides to protect women against human immunodeficiency virus (HIV) sexual transmission are constantly changing. Although the initial dosage forms required daily administration to offer effective protection, the trend then moved towards sustained-release dosage forms that require less frequency of administration in order to improve women's compliance with the treatment. Nevertheless, another possible strategy is to design on-demand products that can be used in a coitally-dependent manner and only need to be administered immediately before intercourse to offer protection. Vaginal discs based on freeze-dried hydroxypropylmethyl cellulose gels have been developed for this purpose, containing two surfactants, i.e., sodium dodecyl sulphate and polysorbate 60, alone or in combination with 2-hydroxypropyl-β-cyclodextrin, to achieve a formulation capable of incorporating both hydrophilic and lipophilic drugs. Several studies have been carried out to evaluate how the inclusion of these substances modifies the structure of gels (viscosity and consistency studies) and the porosimetry of the freeze-dried discs (scanning electron microscopy micrographs, mechanical properties, swelling behaviour). The drug release and mucoadhesive properties of the discs have also been evaluated with a view to their clinical application. The systems combining sodium dodecyl sulphate and 2-hydroxypropyl-β-cyclodextrin were found to be adequate for the vaginal administration of both Tenofovir and Dapivirine and also offer excellent mucoadhesion to vaginal tissue; these discs could therefore be an interesting option for a coitally-dependent administration to protect women against HIV transmission.