Hydroxypropyl Methylcellulose Research Articles

Preparation and in- vitro Evaluation of Bioadhesive Vaginal Film of Tinidazole

Bioadhesive vaginal film is becoming a more effective and convenient dosage form compared to suppositories and gel for vaginal application as a method for the treatment of vaginal infections. This study aimed to prepare and characterize bioadhesive films of tinidazole to be used for vaginal delivery over a prolonged period to treat local infections. Fourteen formulas of tinidazole films were prepared by solvent evaporation method. Each film was composed of 10 mg tinidazole with different ratios and concentrations of a polymeric combination of polyvinyl alcohol/ polyvinyl pyrrolidone (PVA/PVP) or polyvinyl alcohol/ hydroxypropyl methylcellulose (PVA/HPMC) for formulas A1-A7 and B1-B7, respectively. The prepared films were evaluated for their physicochemical characteristics, content uniformity, swelling, mucoadhesive strength, mucoadhesive time, and drug release. All the prepared films were transparent, had a uniform thickness (0.1-0.15 mm), and exhibited sufficient flexibility with drug content uniformity. The mucoadhesive strength of films was in the range of 28 ± 0.2 to 75 ± 0.01 g. Films containing PVA/HPMC showed higher swelling and lower mucoadhesive strength than those containing PVA/PVP polymeric combination. The in vitro drug release study showed no significant differences (p > 0.05) among films containing PVA/PVP or PVA/HPMC polymeric combinations. Formulas A3 and B4 were considered as the optimal bioadhesive films containing 3% of PVA: PVP (4:1) and 4% of PVA: HPMC (2:1), respectively as they showed complete flexibility, acceptable mucoadhesive strength and time (43 ± 0.1, 45 ± 0.23 g and 30 ± 0.02, 34 ± 0.01 min, respectively) and prolonged drug release rate. In conclusion, films of formulas A3 and B4 possess the potential as a delivery system for tinidazole for the treatment of vaginal infections at the site of application.

Astodrimer sodium nasal spray forms a barrier to SARS-CoV-2 in vitro and preserves normal mucociliary function in human nasal epithelium

COVID-19 remains a severe condition for many including immunocompromised individuals. There remains a need for effective measures against this and other respiratory infections, which transmit via virus-laden droplets that reach the nasal or oral mucosae. Nasal sprays offer potential protection against viruses. Such formulations should preserve normal nasal mucociliary function. The antiviral barrier efficacy and effects on mucociliary function of astodrimer sodium nasal spray (AS-NS) were evaluated and compared with other available nasal sprays—low pH hydroxypropyl methylcellulose (HPMC-NS), iota-carrageenan (Carr-NS), nitric oxide (NO-NS), and povidone iodine (PI-NS). Assays simulated clinical conditions. Antiviral barrier function and cell viability were assessed in airway cell monolayers, while a model of fully differentiated human nasal epithelium (MucilAir™) was utilized to evaluate tissue integrity, cytotoxicity, cilia beating frequency, and mucociliary clearance. AS-NS reduced infectious virus in cell monolayers and demonstrated a benign cytotoxicity profile. In human nasal epithelium ex vivo, AS-NS had no impact on mucociliary function (cilia beating nor mucociliary clearance). Carr-NS, HPMC-NS, NO-NS and PI-NS demonstrated limited antiviral effects, while HPMC-NS caused inhibition of mucociliary function. Astodrimer sodium nasal spray demonstrates an acceptable nonclinical efficacy and safety profile as a barrier nasal spray against respiratory viral infection in the nasal cavity.

Design and Evaluation of New Gel-Based Floating Matrix Tablets Utilizing the Sublimation Technique for Gastroretentive Drug Delivery.

A gel-based floating matrix tablet was formulated and evaluated using the sublimation technique to enhance gastroretentive drug delivery. Anhydrous theophylline was employed as the active pharmaceutical ingredient, combined with sublimation agents and hydroxypropyl methylcellulose as the gel-forming polymer. The resulting tablets exhibited high porosity, immediate floatation, and sustained buoyancy for over 8 h. Optimization of the floating behavior and drug release profiles was achieved by adjusting the viscosity of and hydroxypropyl methylcellulose and the concentration of sublimation agents, specifically ammonium carbonate and menthol. These agents were selected for their effectiveness in creating a porous structure, thus reducing tablet density and enhancing floatation. Higher HPMC viscosity resulted in increased floating force, slower drug release, and improved swelling properties due to a slower erosion rate. A critical assessment of the balance between tablet porosity, mechanical strength, and drug release kinetics indicates that ammonium carbonate provided superior tablet hardness and lower friability compared to menthol, favoring a controlled release mechanism. The release dynamics of theophylline were best described by the anomalous (non-Fickian) diffusion model, suggesting a combined effect of diffusion and erosion. This research advances the development of gastroretentive drug delivery systems, highlighting the potential of sublimation-based floating matrix tablets for sustained drug release.

Experimental Study on the Suspending Mechanism of Suspending Agent in Coal-Based Solid Waste Slurry for Long-Distance Pipeline Transportation

The transportation of coal-based solid waste filling slurry (CSWFS) through pipelines for underground goaf injection is essential for enhancing mine safety and promoting green, low-carbon coal mining. To address the issue of pipeline blockage caused by the suspension sensitivity of CSWFS during long-distance transportation, this study proposes the addition of the suspending agent hydroxypropyl methyl cellulose (HPMC) to transform the filling slurry into a stable suspending slurry. The mechanism by which the suspending agent modifies the rheological property of CSWFS was elucidated and verified. Firstly, an evaluation index system for the suspending state of CSWFS based on the “experimental test and theoretical calculation” was established. The values for layering degree, bleeding rate time-loss, and the corresponding average time-loss rate over 0 to 120 min of A1–A5 CSWFS were recorded as 24 mm–2 mm, 3.0–0.2%, 252.4–54.2%, and 149.6–14.6%, respectively. The concentration gradient evaluation result, C/CA = 0.91 (≥0.8), confirmed that the suspending agent maintained a stable suspending state over time for CSWFS. Secondly, it was demonstrated that the suspending agent HPMC modified the rheological property of A1–A5 CSWFS by increasing its plastic viscosity, which strengthened the viscous resistance to particle settling, thereby transforming a semi-stable slurry into a stable one. Additionally, the formation of a spatial suspending network by the suspending agent ensures that no pipeline blockage accidents occured in practical engineering applications. Furthermore, the XRD and SEM tests were utilized to verify the microstructure of the top (T) and bottom (B) samples in A4 block. It was concluded that the type of hydration products, occurrence forms, lapping compactness, and microstructural development were consistent, ultimately forming a high-strength, dense, hardened filling block. Finally, numerical simulation confirmed that the addition of suspending agent in A4 slurry formed a comprehensive spatial suspending network and a well-structured, unified system. This is one effective approach which could contribute to addressing the technical issue of pipeline blockage during long-distance pipeline transportation.

Binary and Ternary Inclusion Complexes of Niflumic Acid: Synthesis, Characterization, and Dissolution Profile.

Although niflumic acid (NA) is one of the most used non-steroidal anti-inflammatory drugs, it suffers from poor solubility, low bioavailability, and significant adverse effects. To address these limitations, the complexation of NA with cyclodextrins (CDs) is a promising strategy. However, complexing CDs with low molecular weight drugs like NA can lead to low CE. This study explores the development of inclusion complexes of NA with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD), including the effect of converting NA to its sodium salt (NAs) and adding hydroxypropyl methylcellulose (HPMC) on complex formation. Inclusion complexes were prepared using co-evaporation solvent and freeze-drying methods, and their CE and Ks were determined through a phase solubility study. The complexes were characterized using physicochemical analyses, including FT-IR, DSC, SEM, XRD, DLS, UV-Vis, 1H-NMR, and 1H-ROESY. The dissolution profiles of the complexes were also evaluated. The analyses confirmed complex formation for all systems, demonstrating drug-cyclodextrin interactions, amorphous drug states, morphological changes, and improved solubility and dissolution profiles. The NAs-2HP-β-CD-HPMC complex exhibited the highest CE and Ks values, a 1:1 host-guest molar ratio, and the best dissolution profile. The results indicate that the NAs-2HP-β-CD-HPMC complex has potential for delivering NA, which might enhance its therapeutic effectiveness and minimize side effects.

Strategies for the incorporation of organosolv lignin in hydroxypropyl methylcellulose-based films: A comparative study

Organosolv lignin extracted from vine pruning residues was added to hydroxypropyl methylcellulose (HPMC)-based films using three strategies: i) lignin incorporated into the film (lignin-based film), ii) lignin nanoparticles (LNPs) incorporated into the film (LNPs-based film), and iii) lignin coated on HPMC films' surface (lignin-coated film). The films obtained were evaluated in terms of morphology, water barrier and mechanical properties, and antioxidant capacity. Results showed that LNPs incorporation did not affect the films´ water vapour permeability (WVP). Nonetheless, the lignin-based and lignin-coated films improved the water barrier properties of HPMC-based films, achieving a 31.5 and 36 % reduction of WVP, respectively. The morphological evaluation, performed by scanning electron microscopy, revealed films' morphology changes with the lignin incorporation, which was more evident in the lignin-based films. Fourier transform infrared spectroscopy (FTIR) showed minor changes in the film's structure using the different lignin incorporation methods. The mechanical properties were improved, including a significant increase in the tensile strength in the lignin-based and lignin-coated films. All films showed high radical scavenging activity (RSA) after 24 h, with a gradual increase in the lignin-coated films over time. The lignin-coated films showed to be the most promising incorporation strategy to improve the HPMC-based film's properties.

Mannitol-Coated Hydroxypropyl Methylcellulose as a Directly Compressible Controlled Release Excipient for Moisture-Sensitive Drugs: A Stability Perspective.

Hydroxypropyl methylcellulose (HPMC) is one of the most commonly used hydrophilic polymers in formulations of matrix tablets for controlled release applications. However, HPMC attracts moisture and poses issues with drug stability in formulations containing moisture-sensitive drugs. Herein, the moisture sorption behavior of excipients and drug stability using aspirin as the model drug in matrix tablets were evaluated, using HPMC and the newly developed mannitol-coated HPMC, under accelerated stability conditions (40 °C, 75% relative humidity) with open and closed dishes. Tablets prepared with mannitol-coated HPMC showed a slower drug degradation rate compared to tablets prepared with directly compressible HPMC. Initial moisture content and hygroscopicity were stronger predictors of drug stability compared to water activity when comparing samples without similar moisture content. In the early stage (day 0 to 30), the aspirin degradation rate was similar in both open and closed conditions, as moisture content is the main degradation contributor. In the later stage (day 30 to 90), aspirin degradation was faster under closed conditions than under open conditions, likely due to autocatalytic effects caused by the volatile acidic by-product entrapped in the closed environment. The findings from this study reinforced the importance of judicious excipient selection based on the understanding of excipient-moisture interactions to maximize the chemical stability of moisture-sensitive drugs. Mannitol-coated HPMC is a promising addition to the formulator's toolbox for the formulation of controlled release dosage forms by direct compression.

Synthesis of a new oil-absorbing PVC oil boom and its application to maritime oil spills

This paper aims to address the issue of environmental pollution resulting from marine oil spills by evaluating the oil adsorption performance of commonly used fence materials. Conventional oil adsorption materials exhibit limited rates and capacities for oil adsorption. Existing methods have proven insufficient in meeting the requirements for efficient and rapid oil–water separation. A new oil-absorbing barrier was developed by utilizing high oil adsorption resin as the primary material and hydroxypropyl methyl cellulose (HPMC) as the binder, leveraging the exceptional oil adsorption and hydrophobic properties of P(BMA-SMA-St)/MIL-101(Fe) resin. The oil-absorbing fence was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The oil adsorption rates of carbon tetrachloride, toluene, diesel and gasoline by the oil adsorption fence with 25 g/L resin content were 101.26 g/m2, 68.12 g/m2, 35.19 g/m2, and 46.69 g/m2, respectively. After 120 h of UV irradiation, the coating’s oil absorption capacity remained nearly unchanged, and it demonstrated outstanding mechanical, chemical, and wear resistance. As a result, the oil adsorption fence possesses the capability to rapidly absorb oil from the water’s surface during the process of containing oil pollution, leading to positive social and economic impacts.

Surface Migration of Fatty Acid to Improve Sliding Properties of Hypromellose-Based Coatings

Hypromellose (HM) is a cellulose-derived polymer of pharmaceutical grade that forms easily from thin films and coatings. As few studies concern HM-formulated systems, this study focuses on the formulation of HM films by incorporating a fatty acid additive, making it possible to control surface properties such as wetting and slip behavior for pharmaceutical or medical applications. The results show that the addition of a very small amount (from 0.1 to 1% w/w) of fatty acid additive reduces HM film affinity for water and water vapor transmission rate, while film appearance and gloss are rather preserved. Surface properties were probed using wettability measurements, Tapping Mode AFM, ATR-FTIR spectrometry, and friction measurements. Tapping Mode AFM images show that the surface roughness reduces by up to 65%. Wettability results show that the surface energy decreases from 43 to 31 mJ.m−2, whereas surface FTIR spectrometry measurements demonstrate that fatty acid molecules migrate on the surface of the formulated films, the driving force being the microphase separation between the polar HM macromolecules and the hydrophobic additive, leading to the formation of a weak boundary layer with poor cohesion. As a consequence, the surface coefficient of friction significantly reduces from 0.38 to 0.08, and fatty acid molecules thus act as a lubricant, improving the sliding properties of HM-based coatings.

Review of Hydroxypropyl Methylcellulose in Artificial Tears for the Treatment of Dry eye disease.

Dry eye disease (DED) is a highly prevalent condition, resulting in reduced quality of life, lower participation in social life and impaired work efficiency. Hydroxypropyl methylcellulose (HPMC) is a cellulose-based viscosity-enhancing agent and is one of the most popular therapeutic ingredients in artificial tears. This review aims to evaluate the literature on the efficacy and safety of HPMC used in the treatment of DED. Literature searches were conducted in PubMed and Cochrane CENTRAL. A total of 28 clinical trials from 26 publications are included in this review, including 21 clinical intervention studies evaluating the effect of HPMC treatment over time and seven single instillation studies evaluating the short-term physical and symptomatic effects of HPMC after drop-instillation. The duration of clinical intervention studies ranged from 2 weeks to 5.5 months. DED severity ranged from mild to severe. Drop frequency ranged from two to up to 16 drops per day. HPMC concentration in artificial tears ranged from 0.2% to 0.5%. No major complications or adverse events were reported. Artificial tears containing HPMC were effective at improving symptoms and some signs of DED. However, combination drops with HPMC plus other therapeutic ingredients seem more effective than HPMC alone. HPMC appears to be equally effective or inferior to hyaluronic acid (HA). There is no evidence of superiority or inferiority to either carboxymethylcellulose (CMC) or polyethylene glycol 400/propylene glycol (PEG/PG). No single study explained the choice of drop frequency or HPMC concentration. More well-designed studies are needed to determine an evidence-based standard for HPMC treatment, including drop frequency, concentration and molecular weight for different DED severity and subgroups.

Early length changes and microscopic phase analysis of phosphorus hemihydrate gypsum fireproof mortar

Abstract Coating the surface of steel structures with phosphohemihydrate gypsum fireproof mortar can improve the fire resistance of steel structures. The hydration curve of phosphorus hemihydrate gypsum (PHG) showed a monotonic increasing trend, and the hydration time was about 1 day. In order to study the hydration process of phosphorus hemihydrate gypsum fireproof mortar, its length change in the early hardening stage was experimentally investigated. The results showed that compared with the hydration time of phosphohemihydrate gypsum, the duration of early length changes in phosphohemihydrate gypsum fireproof mortar was significantly prolonged to about 4 days, and four intervals were clearly observed during this process. Hydroxypropyl methyl cellulose (HPMC) as a water retaining agent, hydroxypropyl starch ether (HPS) as a thixotropic agent, and dispersed latex powder (LP) can all make the four intervals of length changes of fireproof mortar more significant. After adding HPMC, HPS, and LP, it can promote the formation of dihydrate gypsum mainly in fireproof mortar, but dihydrate gypsum crystals were more likely to grow along the [021] direction. The addition of additives can also effectively improve the pore structure of phosphogypsum fireproof mortar.

Anti-aging effect of mustard and flax seed oils based nanoemulsion gel on aged rat skin through antioxidant and anti-inflammatory activity

Skin aging is a common issue that is linked to changes in skin physiology, hydration, and barrier function. Dietary fatty acids (FA), particularly poly-unsaturated fatty acids (PUFA), can influence skin characteristics. It is reported that a deficiency of fatty acids in the skin is associated with skin aging. Therefore, the goal of the current study is to evaluate the antiaging effect of flaxseed oil or mustard oil-based nanoemulsion gel rich in fatty acids such as omega 3 on D-galactose-induced skin aging. N-hexane was used to extract the oils of black mustard and flax seed from their seeds, and the oils' fatty acid composition was then determined. A full factorial design was created to assess the impact of three variables: oil type, oil concentration, and S:Cos ratio, on various responses: globule size, zeta potential, and emulsification time of the self-nanoemulsifying system. Additionally, the polydispersity index, transmittance percentage, refractive index, cloud point, and viscosity were also estimated. TEM of the optimized formulations revealed a spherical form of oil globules with nanosize. The values for the zeta potential ranged from -12 to -34.2 mV. The optimized formulations were incorporated into a hydroxypropyl methyl cellulose solution to form a nanoemulsion gel. Skin aging was induced using the D-galactose model, and the impact of topical skin application of the optimized formulation gels on different biomarkers such as amino acids, B5, oxidative stress markers, inflammatory mediators and histopathological examination was evaluated. The results showed a considerable improvement in the evaluated parameters of the treated groups when compared to the untreated D-galactose group. The findings suggest that the nanoemulsifying system utilizing high doses of fixed plant oils could serve as a promising vehicle for enhancing skin rejuvenation. Flaxseed oil formulation showed greater potential compared to mustard oil formulation as skin antiaging.

Application of Hydrophilic Polymers to the Preparation of Prolonged-Release Minitablets with Bromhexine Hydrochloride and Bisoprolol Fumarate.

Minitablets have been extensively studied in recent years as a convenient pediatric form because they allow successful administration even in very young children. Their advantages include easy dose adjustment by multiplication of single units as well as the possibility of drug release modification by coating or forming matrix systems. The aim of this study was to demonstrate the possibility of the formulation of prolonged-release minitablets with bromhexine hydrochloride (BHX) and bisoprolol fumarate (BFM) dedicated to pediatric patients. Minitablets with 3 mm diameter and 15 mg mass, containing 1 mg of active substance in 1 unit, were prepared by direct compression with hydroxypropyl methylcellulose (HPMC) of different grades, methylcellulose, sodium alginate, or polyvinyl alcohol (PVA) as a sustained-release polymer. Different amounts of polymers and different compression forces were evaluated. Analysis of minitablets included their uniformity, hardness, and dissolution tests. The kinetics of drug substance release were analyzed with dedicated software. The prepared minitablets met the pharmacopeial requirements with respect to the uniformity of mass and content. The compressibility of BFM was significantly better than that of BHX, yet all minitablets had good mechanical properties. Dissolution studies showed a strong relationship between the type of polymer and its amount in the mass of a tablet and the dissolution rate. Prolonged release of up to 8 h was achieved when HPMC of 4000 cP viscosity was used in the amount of 30% to 80%. Sodium alginate in the amount of 50% was also effective in prolonging dissolution, but PVA was much less effective. Studies on the release kinetics showed that dissolution from prolonged-release minitablets with BHX fit the best to Hopfenberg or Hixson-Crowell models, while in the case of BFM, the best fit was found for Hopfenberg or Korsmeyer-Peppas models.

Development and characterization of transdermal drug delivery system of ramosetron HCL using different polymers and their effect on In-vitro release

Transdermal Drug Delivery Systems (TDDS) offer a controlled and consistent release of medications, bypassing first-pass metabolism and minimizing side effects associated with traditional oral and intravenous therapies. This study focuses on the development and evaluation of Ramosetron HCl transdermal patches designed for sustained release to manage nausea and vomiting. Ramosetron HCl, a selective 5-HT₃ serotonin receptor antagonist, was incorporated into various formulations using different grades of Hydroxypropyl Methylcellulose (HPMC), Polyvinyl Pyrrolidone (PVP K30), and Polysorbate 80. The patches were prepared by solvent casting and evaluated for various parameters including thickness, weight variation, drug content, folding endurance, tensile strength, and in-vitro drug release. The calibration curve for Ramosetron HCl in 7.4 pH phosphate buffer was established with a λmax of 240 nm. Fourier Transform Infrared Spectroscopy (FTIR) was employed to ensure compatibility between the drug and excipients. Formulation F5 demonstrated optimal properties, including satisfactory drug release profiles and mechanical strength. Stability studies of F5 showed that the formulation maintained its release characteristics under accelerated storage conditions (40°C / 75% RH) for up to three months. This study confirms the potential of Ramosetron HCl transdermal patches as an effective alternative to oral dosage forms, providing sustained drug delivery and enhanced patient compliance.

Creating bulky papers with hydroxypropyl methylcellulose

Creating bulky papers with hydroxypropyl methylcellulose

Formulation and evaluation of melatonin as fast dissolving oral strips using combined polymers

Background and objective: Fast-dissolving oral thin film (FDOF) is a novel and most advanced form of solid dosage form that dissolves or disintegrates in 1 minute when put in the mouth without water or chewing. Pre-gastric absorption of FODFs from the mouth, pharynx, and esophagus as saliva flows down into the stomach would improve the therapeutic benefit of the drug as oral films disintegrated in the mouth. The study is designed and purposed to use most water soluble, best type and concentration of polymers to be selected for use in combination to formulate melatonin oral thin films. Different types of synthetic water soluble polymers were utilized the preparation of films (hydroxypropyl methyl cellulose HPMC15M, sodium carboxy methyl cellulose NACMC). Methods: Solvent casting method was performed for preparation of twelve placebo films at the beginning, to obtain and select suitable polymer type and concentration for use in combination to be formulated for drug loading. The films were evaluated for their characteristics like mechanical properties (thickness and folding endurance), surface pH and disintegration time. Percentage of release and assay of melatonin was taken. Comparison studies were performed on melatonin films from this study with melatonin oral disintegrating tablets release profiles. Best batch could be selected. Drug-excipient compatibility carried out as pre formulation study to see whether there is interaction between the drug and excipients used. Results: Results from FT-IR showed no interaction between melatonin and polymers used, the prepared formulations were clear, transparent, non-sticky and easily removed from the plate surface with the thickness ranging from (0.04-0.07) mm depending on the polymer concentration. The times required for the films to disintegrate was ranging from 21-26 seconds, and the majority of melatonin was released within first 2 minutes within the dosage form. Conclusion: Melatonin can be formulated as fast dissolving oral films using combination of water-soluble polymers by solvent casting method to obtain ease of administration without using water during administration, fast onset of action resulted from rapid disintegration.

Treatment of endophthalmitis using a novel methacrylic anhydride-modified hydroxypropyl methylcellulose hydrogels loaded with S-nitrosoglutathione: An ex-vivo keratitis model

Introductionpost-operative endophthalmitis (POE) following cataract surgery remains a significant concern due to its impact on vision and the associated socio-economic burden. S-Nitrosoglutathione (GSNO) shows promise due to its stability and antimicrobial properties. Hydroxypropyl methylcellulose (HPMC) is commonly used in eye drops for drug retention, while methacrylic anhydride (MA) modification enhances adhesion. In our study, we aimed to develop a novel GSNO-loaded HPMC-MA hydrogel, and used an ex-vivo corneal keratitis model to test the anti-inflammatory and anti-microbial effects of HPMC-MA hydrogels containing GSNO. Additionally, the study evaluated the irritative potential of the eye drop formulation containing GSNO-loaded HPMC-MA hydrogels on rabbit eyes. MethodWe prepared and tested the GSNO-loaded HPMC-MA hydrogels characters. Fourier Transform Infrared (FTIR) spectroscopy measurement to verify modification, cell viability assays, osmolality tests, in-vivo ocular irritation assessments, inflammatory cells genes expression using RT-PCR, bacterial concentration analysis with an ex-vivo S. aureus keratitis model were conducted. ResultsFTIR spectroscopy confirmed successful MA modification and GSNO incorporation. Cell viability experiments suggested optimal GSNO concentration at 80 μM. Osmolality tests indicated no significant changes in osmolality post-modification. Ocular irritation tests on rabbits showed no adverse reactions. In the ex-vivo keratitis model, GSNO-HPMC-MA reduced inflammation and inhibited bacterial growth, as reflected in gene expression and bacterial concentration analyses. ConclusionThe study demonstrates the successful development of GSNO-loaded HPMC-MA hydrogels with potential as a topical formulation for endophthalmitis treatment. This novel approach shows promise in addressing challenges related to drug delivery efficiency and antimicrobial efficacy in ocular infections.

Properties of SiO2-Al2O3 refractories based on silica glass binder suspension and investigation of their printability using the Direct Ink Writing method

The SiO2-Al2O3 refractories and corresponding inks for 3D printing were prepared from silica glass binder suspensions and fused alumina with grain sizes of 75 and 240 μm. Phase analysis (XRD) and morphological studies (SEM) were conducted to investigate the influence of sintering temperature and Al2O3 content on the strength, porosity, and density of the refractories. Rheological studies (rotational viscometry) were carried out determine the effect of polyethylene glycol (PEG) and hydroxypropyl methylcellulose (HPMC) content on the flow behavior of the inks. It was established that firing refractories based on fused silica and fused alumina at 1500 and 1600 °C led to the formation of mullite and aluminosilicate melt on the surface of Al2O3 grains, enhancing the strength of the synthesized materials. Addition of PEG and HPMC to the ink composition was found to improve their rheological properties by increasing yield strength and promoting plastic flow. The ink demonstrated high printability and they are suitable for producing refractories using the Direct Ink Writing method.

Biopharmaceutical studies of a novel sedative sublingual lozenge based on glycine and tryptophan: A rationale for mucoadhesive agent selection

Effective sedative drugs are in great demand due to increasing incidence of nervous disorders. The present work was aimed to develop a novel sublingual sedative drug based on glycine and L-tryptophan amino acids. Carbopol and different hydroxypropyl methylcellulose species were alternatively tested as mucoadhesive agents intended to prolong tryptophan sublingual release time. A model lipid medium of fully hydrated L-α-dimyristoylphosphatidylcholine was used for optimal mucoadhesive agents selection. Simultaneous processes of drug release and diffusion in lipid medium were first investigated involving both experimental and theoretical approaches. Individual substances, their selected combinations as well as different drug formulations were consecutively examined. Application of kinetic differential scanning calorimetry method allowed us to reveal a number of specific drug-excipient effects. Lactose was found to essentially facilitate tryptophan release and provide its ability to get into the bloodstream simultaneously with glycine, which is necessary to achieve glycine-tryptophan synergism. Introduction of a mucoadhesive agent into the formulation was shown to change kinetics of drug-membrane interactions variously depending on viscosity grade. Among the mucoadhesive agents, hydroxypropyl methylcellulose species K4M and E4M were shown to further accelerate drug release, therefore they were selected as optimal. Thus, effectiveness of the novel sedative drug was provided by including some excipients, such as lactose and the selected mucoadhesive agent species. A dynamic mathematical model was developed properly describing release and diffusion in lipid medium of various drug substances. Our study clearly showed applicability of a lipid medium to meet challenges such as drug-excipient interactions and optimization of drug formulations.

Fabrication and Characterization of Dissolving Microneedles Containing Oryza sativa L. Extract Complex for Enhancement of Transfollicular Delivery.

Dissolving microneedles are extensively applied in drug delivery systems to enhance penetration into the skin. In this study, dissolving microneedles fabricated from polyvinylpyrrolidone K90 (PVP-K90) and hydroxypropylmethyl cellulose (HPMC) E50 in different ratios were characterized. The selected formulations incorporated Oryza sativa L. extract complex and its characteristics, transfollicular penetration, and safety were observed. The microneedles, fabricated from PVP K90: HPMC E50 in a ratio of 25:5 (P25H5) and 20:10 (P20H10), revealed excellent morphological structure, proper mechanical strength, and excellent skin insertion. P25H5 microneedles exhibited faster dissolution than P20H10 microneedles. Microneedles containing Oryza sativa L. extract complex showed excellent morphological structure via scanning electron microscopy but decreased mechanical strength. P25H5-O, which exhibited an effective ability to enter skin, was selected for further investigation. This microneedle formulation had a high percentage of drug-loading content, enhanced skin penetration via the transfollicular route, and was safe for keratinocytes. As a result, the dissolving microneedle containing Oryza sativa L. extract complex can be used to enhance transfollicular delivery through the skin with safety.