Exploring the Formulation and Approaches of Injectable Hydrogels Utilizing Hyaluronic Acid in Biomedical Uses.

The characteristics of injectable hydrogels make them a prime contender for various biomedical applications. Hyaluronic acid is an essential component of the matrix surrounding the cells; moreover, hyaluronic acid's structural and biochemical characteristics entice researchers to develop injectable hydrogels for various applications. However, due to its poor mechanical properties, several strategies are used to produce injectable hyaluronic acid hydrogel. This review summarizes published studies on the production of injectable hydrogels based on hyaluronic acid polysaccharide polymers and the biomedical field's applications for these hydrogel systems. Hyaluronic acid-based hydrogels are divided into two categories based on their injectability mechanisms: in situ-forming injectable hydrogels and shear-thinning injectable hydrogels. Many crosslinking methods are used to create injectable hydrogels; chemical crosslinking techniques are the most frequently investigated technique. Hybrid injectable hydrogel systems are widely investigated by blending hyaluronic acid with other polymers or nanoparticulate systems. Injectable hyaluronic acid hydrogels were thoroughly investigated and proven to demonstrate potential in various medical fields, including delivering drugs and cells, tissue repair, and wound dressings.

Solvent-free method for masking the bitter taste of azithromycin dihydrate using supercritical fluid technology.

INTRODUCTION AND PURPOSE: The unpleasant extremely bitter taste of the orally administered broad-spectrum antibiotic azithromycin decreases patient compliance, especially in pediatrics. This issue can be overcome by decreasing drug interaction with the tasting buds using insoluble polymers at salivary pH (6.8 - 7.4), like the cationic polymer Eudragit EPO. Supercritical fluid technology is a green synthesis method for preparing pharmaceutical preparations that replace organic solvents with safe supercritical CO2. This study aimed to mask the bitter taste of azithromycin using the supercritical fluid method and a pH-sensitive Eudragit EPO polymer. METHODS: A foaming process was investigated for preparing a formulation (TEST), which comprises treating the polymer with supercritical carbon dioxide (CO2) fluid to prepare a taste-masked dosage form without employing organic solvents or flavors. RESULTS: The use of the supercritical technique at 40 °C and 10 MPa for 2 h allowed the manufacturing of solvent-free polymeric foam with azithromycin dispersions; the average calculated percentage of apparent volume change was 62.5 ± 5.9% with an average pore diameter of 34.879 Å. The formulated sample showed low drug release in simulated salivary fluid while keeping its crystalline nature. Moreover, clinical studies on healthy subjects showed that the formula successfully masked azithromycin's bitter taste. CONCLUSIONS: Overall, it has been shown herein that the supercritical fluid technology foaming method is promising in masking the bitter taste of bitter ingredients.

Evaluation of EDTA Dianhydride Versus Diphenyl Carbonate Nanosponges for Curcumin.

Cyclodextrin-based nanosponges are widely investigated for several applications and are considered potential drug carriers. The method of nanosponges preparation involves the use of chemical cross-linking agents where the properties of Nanosponges can be affected. This study compared the resulting differences in the final nanosponges' properties using carbonate and dianhydride crosslinkers. Diphenyl carbonate and EDTA dianhydride were used for the synthesis of nanosponges. Both types of nanosponges were loaded with curcumin as a model drug. Physicochemical characterizations, including PXRD, DSC, FTIR, scanning electron microscopy, AFM, particle size, zeta potential, and surface area analysis, were carried out for the prepared nanosponges. Curcumin release and drug content were also evaluated. Nanosponges prepared by Diphenyl carbonate crosslinker resulted in an amorphous form compared to crystalline EDTA-nanosponges. This study reported the successful inclusion and complexation of curcumin inside carbonate cross-linked cyclodextrin-based nanosponges and suggested the physical entrapment of crystalline curcumin in EDTA dianhydride. These findings were further investigated and supported by computational modeling.

Weak complexation of 5-fluorouracil with ß-cyclodextrin, carbonate, and dianhydride crosslinked ß-cyclodextrin: in vitro and in silico studies.

Background and purpose: Several pharmaceutical formulations were investigated to improve the solubility of 5-fluorouracil to enhance bioavailability and therapeutic efficacy. This study aimed to examine the potential use of cyclodextrin-based nanosponges for the incorporation of 5-fluorouracil and to investigate the use of different crosslinking agents on the properties of the resulting drug carrier. 5-Fluorouracil complexation with ß-cyclodextrin was also studied to explain the unexpected results of weak 5-fluorouracil incorporation in nanosponge. Experimental approach: Nanosponges were synthesized by crosslinking ß-cyclodextrin with two different crosslinkers; diphenyl carbonate and ethylenediaminetetraacetic dianhydride. The incorporation of 5-fluorouracil into ß-cyclodextrin and the prepared nanosponges were assessed by NMR, FTIR, PXRD, DSC, and TGA. In addition, an in vitro release study was carried out to evaluate the potential use of ß-cyclodextrin- based nanosponges as pharmaceutical formulations for 5-fluorouracil. Findings / Results: Physicochemical characterization of the dried formulations indicated the complexation of 5-fluorouracil with the ß-cyclodextrin polymer. Despite that, no clear manifestation of 5-fluorouracil encapsulation in the prepared ß-cyclodextrin-based nanosponge was detected. Furthermore, no significant differences were observed in the release profiles of 5-fluorouracil, ß-cyclodextrin complex, and ß- cyclodextrin-based nanosponge, suggesting weak complexation and instability in aqueous solutions. EDTA- crosslinked ß-cyclodextrin-based nanosponge showed a slight improvement in 5-fluorouracil solubility with a faster initial rate of 5-fluorouracil release. Conclusion and implications: This study suggested weak complexation between 5-fluorouracil and the ß- cyclodextrin polymer or nanosponges. Crosslinking of ß-cyclodextrin with EDTA dianhydride crosslinker showed an enhancement in 5-fluorouracil saturation solubility combined with a faster initial rate of drug release.

Evaluation and Characterization of Curcumin-ß-Cyclodextrin and Cyclodextrin-Based Nanosponge Inclusion Complexation.

Cyclodextrin polymers and cyclodextrin-based nanosponges have been widely investigated for increasing drug bioavailability. This study examined curcumin's complexation stability and solubilization with ß-cyclodextrin and ß-cyclodextrin-based nanosponge. Nanosponges were prepared through the cross-linking of ß-cyclodextrin with different molar ratios of diphenyl carbonate. Phase solubility experiments were conducted to evaluate the formed complexes and evaluate the potential of using ß-cyclodextrin and nanosponge in pharmaceutical formulations. Furthermore, physicochemical characterizations of the prepared complexes included PXRD, FTIR, NMR, and DSC. In addition, in vitro release studies were performed for the prepared formulations. The formation of ß-cyclodextrin complexes enhanced curcumin solubility up to 2.34-fold compared to the inherent solubility, compared to a 2.95-fold increment in curcumin solubility when loaded in ß-cyclodextrin-based nanosponges. Interestingly, the stability constant for curcumin nanosponges was (4972.90 M-1), which was ten times higher than that for the ß-cyclodextrin complex, where the value was 487.34 M-1. The study results indicated a decrease in the complexation efficiency and solubilization effect with the increased cross-linker amount. This study's findings showed the potential of using cyclodextrin-based nanosponge and the importance of studying the effect of cross-linking density for the preparation of ß-cyclodextrin-based nanosponges to be used for pharmaceutical formulations.

Development and Evaluation of Cocoa Butter Taste Masked Ibuprofen Using Supercritical Carbon Dioxide.

Masking the unpleasant taste of the pharmaceutically active ingredients plays a critical role in patient acceptance, particularly for children. This work's primary objective was the preparation of taste-masked ibuprofen microparticles using cocoa butter with the assistance of supercritical fluid technology. Microparticles were prepared by dissolving ibuprofen in melted cocoa butter at 40 °C. The solution was then introduced into a supercritical fluid unit and processed at 10 MPa CO2 pressure for 30 min. The product was collected after depressurizing the system. The effect of the drug to cocoa butter ratio and the supercritical fluid units' configuration on product quality was evaluated and compared with the sample prepared by a conventional method. Physicochemical characterization of the prepared product, including particle size, crystallinity, entrapment efficiency, in vitro drug release, and product taste using a human volunteer panel was conducted. The produced microparticles were in the range of 1.42 to 15.28 µm. The entrapment efficiency of the formulated microparticles ranged from 66 to 81%. The drug:polymer ratio, the configuration of the supercritical fluid unit, and the method of preparation were found to have a critical role in the formulation of ibuprofen microparticles. Taste evaluation using human volunteers showed that microparticles containing 20% drug and processed with supercritical fluid technology were capable of masking the bitter taste of ibuprofen. In conclusion, the dispersion of ibuprofen in cocoa butter using supercritical fluid technology is a a promising innovative method to mask the bitter taste of ibuprofen.

Investigation of Carrageenan Aerogel Microparticles as a Potential Drug Carrier.

Carrageenan is an anionic polysaccharide offering many advantages to be used in drug delivery applications. These include availability, thermo-stability, low toxicity, and encapsulating properties. Combination of these properties with aerogel properties like large surface area and porosity make them an ideal candidate for drug adsorption and delivery applications. Emulsion-gelation technique was used to prepare carrageenan gel microparticles with supercritical CO2 for drying and loading purposes. Ibuprofen has been selected as a model drug for drug loading inside. The prepared microparticles were characterized using particle size analysis, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, density measurements, surface area, and porosity measurements. Finally, dissolution was applied to the loaded preparations to test in vitro drug release. Ibuprofen was successfully loaded in the amorphous form inside the prepared microparticles with a significant enhancement in the drug release profile. In conclusion, prepared carrageenan aerogel microparticles showed an excellent potential for use as a drug carrier.

Effect of processing parameters on preparation of carrageenan aerogel microparticles.

The aim of this work is to produce aerogel microparticles using a biocompatible polymer. Commercial available carrageenan suitable for gelation was used as a precursor for gel preparation. Microspherical carrageenan gel particles were obtained by applying emulsion technology. The gel was converted to an aerogel using supercritical carbon dioxide extraction process. Several process parameters were investigated for their effect on the final properties of the produced aerogel. The produced aerogel particles were characterized for their textural properties using gas sorption analysis. For complete understanding the following characterization techniques were employed: FTIR, PXD, TGA, SEM, Zeta sizer, particles density and particle size distribution. In conclusion, biodegradable aerogel micro-spherical particles based on three different commercial available carrageenan were produced. Depending on the process parameters the surface area of the produced aerogel ranged between 33 and 174m2/g, the average pore volume and pore sized were 0.35±0.11cm3/g and 12.34±3.24 respectively. The produced porous material shows potential characteristic for drug delivery application.