Preparation and evaluation of in - situ gels containing hydrocortisone for the treatment of aphthous ulcer

[Research progress of methylcellulose-based thermosensitive hydrogels applied in biomedical field]

Methylcellulose is a semi-flexible cellulose ether derivative, whose hydrogels are thermosensitive and reversible, with good biocompatibility and adjustable function, and its application has attracted much attention in the biomedical field. In this paper, the application of methylcellulose-based thermo-sensitive hydrogels in biomedical field was reviewed. Based on the mechanism of gelation and influencing factors of methylcellulose, this paper focused on the recent advances in biomedical applications of methylcellulose-based hydrogels, including drug delivery, regenerative medicine, and other related fields. The current achievements in these fields were summarized in the form of lists in this paper to provide ideas and tendencies for future research. Finally, the future development of multifunctional methylcellulose-based hydrogel materials with improved performance was also discussed.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ± 1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ± 63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ± 0.35 °C. 96.77 ± 3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ± 11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

Advancements in gelatin-based hydrogel systems for biomedical applications: A state-of-the-art review

A gelatin-based hydrogel system is a stimulus-responsive, biocompatible, and biodegradable polymeric system with solid-like rheology that entangles moisture in its porous network that gradually protrudes to assemble a hierarchical crosslinked arrangement. The hydrolysis of collagen directs gelatin construction, which retains arginyl glycyl aspartic acid and matrix metalloproteinase-sensitive degeneration sites, further confining access to chemicals entangled within the gel (e.g., cell encapsulation), modulating the release of encapsulated payloads and providing mechanical signals to the adjoining cells. The utilization of various types of functional tunable biopolymers as scaffold materials in hydrogels has become highly attractive due to their higher porosity and mechanical ability; thus, higher loading of proteins, peptides, therapeutic molecules, etc., can be further modulated. Furthermore, a stimulus-mediated gelatin-based hydrogel with an impaired concentration of gellan demonstrated great shear thinning and self-recovering characteristics in biomedical and tissue engineering applications. Therefore, this contemporary review presents a concise version of the gelatin-based hydrogel as a conceivable biomaterial for various biomedical applications. In addition, the article has recapped the multiple sources of gelatin and their structural characteristics concerning stimulating hydrogel development and delivery approaches of therapeutic molecules (e.g., proteins, peptides, genes, drugs, etc.), existing challenges, and overcoming designs, particularly from drug delivery perspectives.

POTENTIAL BENEFITS OF USING CHITOSAN AND SILK FIBROIN TOPICAL HYDROGEL FOR MANAGING WOUND HEALING AND COAGULATION

Background & Objectives

The intricate process of wound healing involves replacing the cellular or tissue structure that has been destroyed. In recent years various wound dressings were launched but reported several limitations. The topical gel preparations are intended for certain skin wound conditions for local action. Chitosan-based hemostatic materials are the most effective in halting acute hemorrhage, and naturally occurring silk fibroin is widely utilized for tissue regeneration. So, this study was conducted to evaluate the potential of chitosan hydrogel(CHI-HYD) and chitosan silk fibroin hydrogel (CHI-SF-HYD) on blood clotting and wound healing.

Methods

Hydrogel was prepared using various concentrations of silk fibroin with guar gum as a gelling agent. The optimized formulations were evaluated for visual appearance, Fourier transforms infrared spectroscopy (FT-IR), pH, spreadability, viscosity, antimicrobial activity, HR-TEM analysis, ex vivo skin permeation, skin irritation, stability studies, and in vivo studies by using adult male Wistar albino rats.

Results

Based on the outcome of FT-IR, no chemical interaction between the components was noticed. The developed hydrogels exhibited a viscosity of 79.2 ± 4.2 Pa.s (CHI-HYD), 79.8 ± 3.8 Pa.s (CHI-SF-HYD), and pH of 5.87 ± 0.2 (CHI-HYD), 5.96 ± 0.1 (CHI-SF-HYD). The prepared hydrogels were sterile and non-irritant to the skin. The in vivo study outcomes show that the CHI-SF-HYD treated group has significantly shortened the span of tissue reformation than other groups. This demonstrated that the CHI-SF-HYD could consequently accelerate the regeneration of the damaged area.

Interpretation & Conclusion

Overall, the positive outcomes revealed improved blood coagulation and re-epithelialization. This indicates that the CHI-SF-HYD could be used to develop novel wound-healing devices.

Combined Thermosensitive Gel Co-Loaded with Dermaseptin-PP and PTX Liposomes for Effective Local Chemotherapy

Introduction

Chemotherapeutic drugs are often ineffective due to the delivery. Local chemotherapy, which has high drug concentration, low systemic toxicity, and long duration, has shown excellent potential. Cationic antimicrobial peptides have been proved to enhance the tumor cells' uptake of chemotherapeutic drugs through the membrane-breaking effect. In this study, we designed and developed a thermosensitive gel co-loaded with Dermaseptin-PP and paclitaxel liposomes to increase local chemotherapy.

Methods

The paclitaxel liposomes were prepared. Then, it was co-loaded with Dermaseptin-PP in a poloxamer-based thermosensitive gel to obtain Dermaseptin-PP/paclitaxel liposomes gel. The thermosensitivity of gels was investigated by test tube inversion method. The rheology was tested by rheometer. The in vitro cytotoxicity and the permeation in tumor of gels were examined by H157 cells and the 3D cell model, respectively. The retention in tumor and antitumor activity of gels were evaluated by H157 tumor-bearing nude mice.

Results

The particle size of paclitaxel liposomes was 148.97 ± 0.21 nm. The encapsulation rate was 86.1%, and the drug loading capacity was 19.4%. The gels had slow-release and temperature-sensitive properties. The porous 3D network structure of the gels could ensure that the drug was fixed into the tumor. In vitro and in vivo distribution studies showed that Dermaseptin-PP promoted the permeation of the gels in H157 multicellular tumor spheres and achieved longer retention in tumor. In vitro and in vivo antitumor studies demonstrated that Dermaseptin-PP/paclitaxel liposomes gel significantly inhibited the growth of tumors for local chemotherapy with good biosafety.

Conclusion

This study provided a promising nanomedicine platform for combining antimicrobial peptides and chemotherapeutic drugs for local chemotherapy.

In-situ Gels for Brain Delivery: Breaching the Barriers

The blood-brain barrier (BBB) regulates blood and chemical exchange in the central nervous system. It is made up of brain parenchyma capillary endothelial cells. It separates the interstitial cerebrospinal fluid from the circulation and limits brain drug entry. Peptides, antibodies, and even tiny hydrophilic biomolecules cannot flow across the BBB due to their semi-permeability. It protects the brain from poisons, chemicals, and pathogens, and blood cells penetrate brain tissue. BBB-facilitated carrier molecules allow selective permeability of nutrients such as D-glucose, L-lactic acid, L-phenylalanine, L-arginine, and hormones, especially steroid hormones. Brain barriers prevent drug molecules from entering, making medication delivery difficult. Drugs can reach specific brain regions through the nasal cavity, making it a preferred route. The in-situ gels are mucoadhesive, which extends their stay in the nasal cavity, allows them to penetrate deep and makes them a dependable way of transporting numerous medications, including peptides and proteins, straight into the central nervous system. This approach holds great potential for neurological therapy as they deliver drugs directly to the central nervous system, with less interference and better drug release control. The brain affects daily life by processing sensory stimuli, controlling movement and behaviour, and sustaining mental, emotional, and cognitive functioning. Unlike systemic routes, the nasal mucosa is extensively vascularized and directly contacts olfactory sensory neurons. Compared to the systemic circulation, this improves brain bioavailability of medications. Drugs can be delivered to the brain using in-situ gel formulations safely and efficiently, with a greater therapeutic impact than with traditional techniques.

Charge-transfer chemistry of two corticosteroids used adjunctively to treat COVID-19. Part II: The CT reaction of hydrocortisone and dexamethasone donors with TCNQ and fluoranil acceptors in five organic solvents

Hydrocortisone (termed as D1) and dexamethasone (termed as D2) are corticosteroids currently used to treat COVID-19. COVID-19 is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Exploring additional chemical properties of drugs used in the treatment protocols for COVID-19 could help scientists alike improve these treatment protocols and potentially even the vaccines (i.e., Janssen, Moderna, AstraZeneca, Pfizer-BioNTech). In this work, the charge-transfer (CT) properties of these two corticosteroids (D1 and D2) with two universal acceptors: 7,8,8-tetracyanoquinodimethane (termed as TCNQ) and fluoranil (termed as TFQ) in five different solvents were investigated. The examined solvents were MeOH, EtOH, MeCN, CH₂Cl₂, and CHCl₃. The CT interactions formed stable corticosteroid CT complexes in all examined solvents. Several spectroscopic parameters were derived, and the oscillator strength (f) and transition dipole moment (μ_e.g.) values revealed that the interaction between the investigated corticosteroids with TCNQ acceptor is much stronger than their interaction with TFQ acceptor. The CT interactions were proposed to process via n → π* transition.

Charge-transfer chemistry of two corticosteroids used adjunctively to treat COVID-19. Part I: Complexation of hydrocortisone and dexamethasone donors with DDQ acceptor in five organic solvents

COVID-19 is the disease caused by a novel coronavirus (CoV) named the severe acute respiratory syndrome coronavirus 2 (termed SARS coronavirus 2 or SARS-CoV-2). Since the first case reported in December 2019, infections caused by this novel virus have led to a continuous global pandemic that has placed an unprecedented burden on health, economic, and social systems worldwide. In response, multiple therapeutic options have been developed to stop this pandemic. One of these options is based on traditional corticosteroids, however, chemical modifications to enhance their efficacy remain largely unexplored. Obtaining additional insight into the chemical and physical properties of pharmacologically effective drugs used to combat COVID-19 will help physicians and researchers alike to improve current treatments and vaccines (i.e., Pfizer-BioNTech, AstraZeneca, Moderna, Janssen). Herein, we examined the charge-transfer properties of two corticosteroids used as adjunctive therapies in the treatment of COVID-19, hydrocortisone and dexamethasone, as donors with 2,3-dichloro-5,6-dicyano-p-benzoquinone as an acceptor in various solvents. We found that the examined donors reacted strongly with the acceptor in CH₂Cl₂ and CHCl₃ solvents to create stable compounds with novel clinical potential.

Ethosomal gel for rectal transmucosal delivery of domperidone: design of experiment, in vitro, and in vivo evaluation

Despite high efficiency of domperidone (DOM) in prophylaxis of emesis accompanied with radiotherapy and chemotherapy, it still can bother cancer patients by its powerful side effects and difficulty of its oral administration. The study was designed to develop and optimize DOM loaded ethosomal gel for rectal transmucosal delivery. Ethosomal formulations were prepared using a 2¹, 5¹ full-factorial design where the impact of lecithin concentration and additives were investigated. The optimum ethosomal vesicles were subsequently incorporated in Carbopol gel base where rheological behavior, spreadability, mucoadhesion, and in vivo pharmacokinetic parameters were studied. Based on Design Expert^® software (Stat Ease, Inc., Minneapolis, MN), the optimum formulation illustrated entrapment efficiency of 70.02%±5.52%, and vesicular size of 112 ± 3.3 nm, polydispersity index of 0.32 ± 0.01, zeta potential of −59 ± 0.28 mV, and % drug released after 6 h of 76.30%±2.45%. Moreover, ex vivo permeation through rabbit intestinal mucosa increased four times compared to free DOM suspension. The gel loaded with ethosomes showed excellent mucoadhesion to rectal mucosa. DOM ethosomal gel showed a raise in C_max and AUC_0–48 of DOM by twofolds compared to free DOM gel. The study suggested that ethosomes incorporated in gels could be an efficient candidate for rectal transmucosal delivery of DOM.

The efficacy of herbal medicine in the treatment of recurrent aphthous stomatitis: A systematic review of randomized clinical trials

This systematic review was undertaken with the main aim of assessing the therapeutic effects of herbal medicines in recurrent aphthous stomatitis (RAS). A comprehensive search was performed in PubMed, Scopus, ISI Web of Science, and Google Scholar up to July 2021 to identify randomized clinical trials investigated the effects of herbal medicines on RAS. Thirty-three papers comprising 2,113 patients met the eligibility criteria, of which 30 studies had a high quality based on the Jadad scale. Totally, 22 out of 30 studies which assessed the pain showed that herbal agents significantly decreased the pain compared with the control group or placebo. In 17 out of 25 studies that evaluated ulcer size, herbal agents significantly reduced the size of ulcers compared with the control or placebo groups. In 15 out of 18 studies that assessed the healing time, herbal agents significantly reduced healing time in the intervention groups compared with the placebo or control groups. Few adverse events were reported only in four studies. Findings of the current review indicated medicinal plants and phytochemicals as effective and safe agents that for the treatment of RAS.

Evaluation of Novel Topical Camel Whey Protein Gel for the Treatment of Recurrent Aphthous Stomatitis: Randomized Clinical Study

Aim:

The aim of this article is to evaluate the topical effect of camel whey protein (CWP) on the healing of recurrent aphthous stomatitis (RAS) and the serum levels of interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α.

Materials and Methods:

Forty patients with minor RAS were randomly assigned into control and study groups. The control group applied placebo methylcellulose gel topically over the aphthous ulcer, whereas the study group used CWP dissolved in methylcellulose gel topically over the aphthous ulcer. Healing period, pain scale, and serum inflammatory biomarkers were evaluated before and after gel application. Collected data were analyzed statistically using the paired t-test or independent sample t-test.

Results:

Ulcer healing period, pain scale, and immunological biomarkers were statistically improved in both groups with significant shortening of the ulcer duration and significant regulation of immunological values related to the study group.

Conclusion:

Topical CWP gel is potentially effective in the treatment of RAS.

Recent advances in ocular drug delivery systems and targeting VEGF receptors for management of ocular angiogenesis: A comprehensive review

Background

Angiogenic ocular diseases address the main source of vision impairment or irreversible vision loss. The angiogenesis process depends on the balance between the pro-angiogenic and anti-angiogenic factors. An imbalance between these factors leads to pathological conditions in the body. The vascular endothelial growth factor is the main cause of pathological conditions in the ocular region. Intravitreal injections of anti-angiogenic drugs are selective, safe, specific and revolutionized treatment for ocular angiogenesis. But intravitreal injections are invasive techniques with other severe complications. The area of targeting vascular endothelial growth factor receptors progresses with novel approaches and therapeutically based hope for best clinical outcomes for patients through the developments in anti-angiogenic therapy.

Main text

The present review article gathers prior knowledge about the vascular endothelial growth factor and associated receptors with other angiogenic and anti-angiogenic factors involved in ocular angiogenesis. A focus on the brief mechanism of vascular endothelial growth factor inhibitors in the treatment of ocular angiogenesis is elaborated. The review also covers various recent novel approaches available for ocular drug delivery by comprising a substantial amount of research works. Besides this, we have also discussed in detail the adoption of nanotechnology-based drug delivery systems in ocular angiogenesis by comprising literature having recent advancements. The clinical applications of nanotechnology in terms of ocular drug delivery, risk analysis and future perspectives relating to the treatment approaches for ocular angiogenesis have also been presented.

Conclusion

The novel ocular drug delivery systems involving nanotechnologies are of great importance in the ophthalmological sector to overcome traditional treatments with many drawbacks. This article gives a detailed insight into the various approaches that are currently available to be a road map for future research in the field of ocular angiogenesis disease management.

Development of In-Situ Spray for Local Delivery of Antibacterial Drug for Hidradenitis Suppurativa: Investigation of Alternative Formulation

Hidradenitis suppurativa (HS) has been considered an orphan disease with limited treatments available. The available topical treatment for this condition is clindamycin lotion; however, short retention and frequent application are the main setbacks. Thus, the present study aimed to attain an optimized antibacterial in situ spray formulation for the hidradenitis suppurativa skin condition, which gels once in contact with the skin surface at around 37 °C and possesses bioadhesion as well as sustained-release properties of the incorporated drug. Different concentrations of thermo-reversible gelling polymer, Pluronic F-127, were investigated along with the selected bioadhesive polymers, HPMC and SA. The optimized formulation F3 consisting of 18% Pluronic F-127 with 0.2% HPMC and 0.2% SA was characterized based on various physicochemical properties. The gelation temperature of F3 was found to be 29.0 ± 0.50 °C with a gelation time of 1.35 ± 0.40 min and a pH of 5.8. F3 had the viscosity of 178.50 ± 5.50 cP at 25 °C and 7800 ± 200 cP at 37 °C as the gel set. The optimized formulation was found to be bioadhesive and cytocompatible. Cumulative drug release was 65.05% within the time-frame of 8 h; the release pattern of the drug followed zero-order kinetics with the Higuchi release mechanism. The average zone of inhibition was found to be 43.44 ± 1.34 mm. The properties of F3 formulation reflect to improve residence time at the site of application and can enhance sustained drug release. Therefore, it could be concluded that optimized formulation has better retention and enhanced antimicrobial activity for superior efficacy against HS.