Carbomer-based Gel Research Articles

Development of a gel formulation with pomegranate peel extract (Punica granatum L.) for antimicrobial and wound healing action

The aim of this study was to evaluate the feasibility of producing a gel from pomegranate peel extract for topical application, specifically for antimicrobial and wound healing purposes. Initially, the dry crude pomegranate peel extract (DCPPE) was analyzed for its phenolic profile using HPLC and by determining the total phenolic content (TPC), and total antioxidant activity (TAA). Carbomer-based gels were prepared and subjected to antimicrobial susceptibility tests to determine the optimal concentration of DCPPE (1.25 %, 2.5 %, and 3.75% w/w) in the formulations. Then, gel was produced in larger quantities and submitted to physicochemical and microbiological tests after being stored at room temperature or under refrigeration for 90 days. Gallic acid, ellagic acid, and punicalagin A and B were identified in DCPPE. The TPC was measured at 61.92 mg of gallic acid equivalent per gram (mg.GAE.g−1) and the TAA was 93.8 % (solution at 40 µL.mL−1), demonstrating superiority over butylhydroxytoluene (BHT) and gallic acid solutions at equivalent concentrations. Antimicrobial susceptibility tests indicated a significant difference (p < 0.05) for the 2.5% w/w DCPPE gel against Staphylococcus aureus and Candida albicans, which was the chosen concentration. Over a 30-day period under both storage conditions, there was no significant difference in pH values, and the reduction of TPC in the refrigerated formulation was <10 %, indicating good stability. Furthermore, the in vitro antimicrobial activity of the gel remained effective against all tested strains. These results suggest that the medicinal carbomer-based gel with DCPPE at 2.5% w/w has potential as a pharmaceutical form for antimicrobial and wound healing purposes. The utilization of DCPPE as a pharmaceutical bio-input for the gel is a sustainable approach to valorizing pomegranate peel biowaste.

Study of factors affecting the in vitro release of dexpanthenol from solutions and topical semi-solid preparations

The aim. To identify the factors influencing the in vitro release of dexpanthenol (DP) from solutions and semi-solid preparations.&#x0D; Materials and methods. Dispersed systems containing 5.0 % DP were studied: solutions that were Newtonian liquids and semi-solid preparations (creams, gels and ointment) with non-Newtonian flow behaviour. Rheological studies were performed by rotational viscometry. In vitro release tests were performed using vertical diffusion cells. The content of DP in the receptor medium was determined by liquid chromatography.&#x0D; Results. It has been shown that the greatest values of release parameters of DP were characteristic of its aqueous solution; they decreased when propylene glycol (PG), macrogol 400 (M400), and poloxamer 338 (P338) were added but remained at a high enough level. The inclusion of cationic surfactant and cetostearyl alcohol (CSA) (0.5 : 4.5 % m/m) into the Newtonian liquid led to the formation of disperse system with a plastic flow behaviour and to significant decrease in the DP release. In the case of a cream containing a non-ionic surfactant and CSA, the release parameters of DP were also at a low level. The release of DP from the w/o emulsion-based ointment was minimal. Compared to DP aqueous solution, the rate of DP release from a carbomer-based gel decreased by 2.8 times; when 20 % of a mixture of PG and M400 (10 : 10 % m/m) was added to such a gel, the rate of drug release decreased by another 1.5 times. The fastest and most complete release of DP was observed in the case of the P338-based disperse system, which transformed from a Newtonian liquid into a gel at 32 °C.&#x0D; Conclusions. In vitro release of DP depended on the type of base; rapid and complete release of DP was characteristic of its aqueous solution, and minimal release was observed in the case of hydrophobic ointment. The use of CSA in combination with a surfactant or carbomer to create bases for semi-solid preparations with plastic flow behaviour was a considerable factor that significantly slowed down the release of DP from them. The greatest values of the release parameters of DP were observed in the case of a gel based on P338

Study of factors affecting the in vitro release of ketoprofen from carbomers-based gels

The aim. To identify some factors affecting the in vitro release of ketoprofen from carbomer-based gels.&#x0D; Materials and methods. Carbomer-based gels containing ketoprofen as well as a Newtonian liquid without carbomer, which was the dispersion medium of the gel, were studied by rotational viscometry and spin probe method. The flow behaviour and rheological parameters were determined using the rheograms, and the rotational correlation times of the two dissolved spin probes, the molecules of which contain a carboxyl group or an amino group, were determined by EPR spectra. In vitro release tests were performed using vertical diffusion chambers using a validated method. The quantitative determination of ketoprofen in gels, liquid and receptor medium was performed by liquid chromatography, and ethanol was quantified by gas chromatography according to validated procedures. Gels with different brands of carbomers, neutralised with trolamine or trometamol, with different contents of ketoprofen and ethanol, and with pH from 6.0 to 7.0 were studied.&#x0D; Results. The sol → gel transition due to the neutralisation of the carbomer did not affect the shape and parameters of the EPR spectrum of the spin probe containing a carboxyl group in the molecule (like a carbomer and ketoprofen) in contrast to the probe with an amino group. If the substance dissolved in the gels does not interact with the carbomer, then its molecules/ions rotate rapidly in the liquid medium. This facilitates the release of a such substance from carbomer-based gels. The medicinal product Nobi Gel® gel 2.5 % and Newtonian liquid were equivalent in relation to the in vitro release parameters of ketoprofen from these objects. Сarbomer-based gels, which differed significantly in terms of rheological parameters, were also found to be equivalent in terms of ketoprofen release parameters. The in vitro release of ketoprofen was affected by its concentration and ethanol content in the gel. A change in pH from 6.0 to 7.0 practically did not affect the parameters of in vitro release of ketoprofen from gels.&#x0D; Conclusions. The formation of a carbomer-based gel did not affect the rotational correlation time of the probe, which did not interact with the carbomer. Parameters of in vitro release of ketoprofen from the gel and Newtonian liquid differed little; these parameters were also little affected by the difference in apparent viscosity of the gels. The in vitro release of ketoprofen depended on its concentration and ethanol content

Quality by Design Guided Development of Polymeric Nanospheres of Terbinafine Hydrochloride for Topical Treatment of Onychomycosis Using a Nano-Gel Formulation.

Superficial fungal diseases of the skin and nails are an increasingly common occurrence globally, requiring effective topical treatment to avoid systemic adverse effects. Polymeric nanoparticles have demonstrated sustained and effective drug delivery in a variety of topical formulations. The aim of this project was to develop polymeric antifungal nanospheres containing terbinafine hydrochloride (TBH) to be loaded into a hydrogel formulation for topical nail drug delivery. A quality by design (QbD) approach was used to achieve optimized particles with the desired quality target product profile (QTPP). Polyvinyl alcohol (PVA) at 2% w/v and a drug to polymer ratio of 1:4, together with a robust set of processes and material attributes, resulted in nanoparticles of 108.7 nm with a polydispersity index (PDI) of 0.63, 57.43% recovery, and other desirable characteristics such as zeta potential (ZP), particle shape, aggregation, etc. The nanospheres were incorporated into a carbomer-based gel, and the delivery of TBH through this formulation was evaluated by means of in vitro drug release testing (IVRT) and ex vivo nail permeation study. The gel containing the TBH nanospheres demonstrated a slower and controlled drug release profile compared with the control gel, in addition to a more efficient delivery into the nail. These antifungal nanospheres can be utilized for topical therapy of a multitude of superficial fungal infections.

Construction of a new multifunctional insomnia drug delivery system

Insomnia is a severe sleep problem that people in the current society widely face. In clinic, zaleplon is a commonly used drug for insomnia treatment. However, short half-life, poor sleep maintenance effect and low oral utilization rate of zaleplon seriously limit its treatment outcome. Here, we report a nasal gel drug delivery system by using single-walled carbon nanotubes as carriers. Besides the certain neuroprotective effect of single-walled carbon nanotubes, zaleplon loaded on them can effectively improve the drug bioavailability by crossing the blood-brain barrier, appropriately prolonging its effective time and enhance the therapeutic effect. In addition, the carbomer-based gel can extend the residence time of the drug delivery system in the nasal cavity to further enhance absorption efficiency, and its ion responsiveness can prevent nasal obstruction from interfering with normal breathing after sleep. This system improves the shortcomings of zaleplon and increases the effectiveness of the treatment of insomnia by appropriately prolonging the duration of action of the drug. The design of this drug-delivery system provides a new idea for the safe and efficient delivery of insomnia drugs into the brain.

Development of methods for analysis of the amount of flavonoids and their stability study in the combined dental gel

An important aspect in the pharmaceutical development of dental medicines is to provide them with a prolonged therapeutic effect while reducing the side effects of drug substances and the possibility of long-term use. This can be achieved by using active components of plant origin. Aim. To develop methods for analyzing biologically active substances in the composition of a new combined dental gel. Materials and methods. The study object was a dental gel containing “Phytodent” complex tincture (PJSC “CPP Chervona zirka”, Ukraine). Based on the analysis of the composition of the tincture it was proposed to carry out standardization by the amount of biologically active substances, namely flavonoids. Identification was carried out by TLC, while the quantitative determination by absorption spectrophotometry, the ultraviolet and visible method by the reaction with aluminum chloride using the standard method calculated with reference to rutin and the absorbance measurement at 406 nm. Results and discussion. As a result of the research, the methods for the analysis of flavonoids in the composition of the new combined gel have been developed. The spectrophotometric method developed is characterized by specificity, accuracy, precision and linearity with r = 0.9998. One of the important issues when using components of plant origin is their stability both during preparation and storage. Using the method developed the stability of flavonoids has been studied depending on pH changes of the carbomer-based dental gel. Conclusions. It has been determined that the methods developed are easily reproducible and allow to identifying and quantifying flavonoids in the dental gel. It has been found that a stable content of flavonoids is characteristic of the carbomer-based gel neutralized to pH values from 5.0 to 6.0.

Microwave hyperthermia-responsible flexible liposomal gel as a novel transdermal delivery of methotrexate for enhanced rheumatoid arthritis therapy.

Methotrexate (MTX) as an anti-inflammatory drug for the treatment of rheumatoid arthritis (RA) through oral and injectable administration is still problematic in the clinic. Herein, a MTX-loaded thermal-responsible flexible liposome (MTFL) incorporated within a carbomer-based gel was prepared as a novel transdermal agent (MTFL/Gel) for effective treatment of RA. It was found that MTFL had an average size of approximately 90 nm, which could rapidly release the drug under thermal conditions. The prepared MTFL/Gel could remarkably increase the MTX skin permeation as compared with free MTX, which was possibly due to the deformable membrane of flexible liposomes. Moreover, the results suggested MTFL/Gel could lead to a remarkably enhanced RA treatment when in combination with microwave hyperthermia. The superior ability of MTFL/Gel to alleviate RA response was attributed to the excellent skin permeation, thermal-responsible drug release, and synergistic anti-arthritic effect of MTX chemotherapy and microwave-induced hyperthermia therapy. Overall, the MTFL/Gel with dual deformable and thermal-responsible performances could be used as a novel promising transdermal agent for enhanced treatment of RA.

Enhancing Electrical Contact with a Commercial Polymer for Electrical Resistivity Tomography on Archaeological Sites: A Case Study.

This communication reports an improvement of the quality of the electrical data obtained from the application of electrical resistivity tomography method on archaeological studies. The electrical contact between ground and electrode enhances significantly by using carbomer-based gel during the electrical resistivity tomography measurements. Not only does the gel promote the conservation of the building surface under investigation, but it also virtually eliminates the necessity of conventional spike electrodes, which in many archaeological studies are inadequate or not permitted. Results evidenced an enhancement in the quality of the electrical data obtained in the order of thousands of units compared with those without using the carbomer-based gel. The potential and capabilities of this affordable gel make it appropriate to be applied to other geoelectrical studies beyond archaeological investigations. Moreover, it might solve corrosion issues on conventional spike electrodes, and electrical multicore cables usually provoked for added saltwater attempting to improve the electrical contact.

The Influence of pH Values on the Rheological, Textural and Release Properties of Carbomer Polacril® 40P-Based Dental Gel Formulation with Plant-Derived and Synthetic Active Components.

The physicochemical properties, especially pH value of dental medicines, have significant influence on the health of oral cavity tissues. The pH of formulations should correspond to the value of saliva pH (5.5–8.0). For carbomer-based gels, the required pH value is obtained by neutralizing them with alkaline components, which leads to their structuring (thickening). This affects the physical properties of the gel, its residence time at the application site and the rate of release of active pharmaceutical ingredient. Therefore, the main purpose of this study is to evaluate the rheological, textural, and biopharmaceutical properties of Carbomer Polacril® 40P-based dental gel depending on the pH value. Evaluation of the rheological properties of gel preparations were performed by measuring the structural viscosity of the samples as a function of pH and temperature. The textural properties of the gel were evaluated by performing tests regarding back extrusion and spreadability. Carbomer Polacril® 40P-based gels haven’t shown noticeable thixotropic behavior, and were characterized by plastic flow in the whole studied pH range. The structural viscosity at the selected average pH value hasn’t differed at storage (25 °C) and application (37 °C) temperature. Texture studies of dental gels have shown a strong correlation with rheoparameters. Their rheological behavior and textural properties haven’t changed significantly between the pH range of 5.5–6.6. The relatively narrow range of working pH values does not affect the change in the viscosity of the preparation significantly and, consequently, does not affect the release of APIs from the developed Carbomer Polacril® 40P-based dental gel.

Phytochemical characterization of fruit extracts of Rubus adenotrichus and evaluation of their antioxidant power for dermocosmetics formulation

There are more than 700 species of the genus Rubus, popularly known as Mora (tropical highland blackberry). In Costa Rica, the species Rubus adenotrichus has been characterized by its high content of antioxidant substances, becoming one of the most cultivated species and that may have characteristics to be used in cosmetics or medicine. The objective of the present study is to identify the main phytochemical groups and to quantify the main markers in order to associate them with cosmetic or medicinal functions in pharmaceutical products. Ripe fruits of R. adenotrichius were fractionated with solvents of low, medium and high polarity, followed by a phytochemical screening according to the World Health Organization Guidelines for the Control of Quality of Products of Natural Origin. The antioxidant properties were evaluated by means of the H-ORAC and DPPH test; the concentration of total phenols by Folin-Ciocalteau and antocinanins by differential pH was determined. Finally, the physicochemical properties of the aqueous extract, such as pH, specific gravity, Brix grades, conductivity, and osmolarity was determined and an absorption spectrum from 260 to 700 nm was obtained. Phenolic compounds were found as condensed and non-condensed tannins, anthocyanins, flavonoids, terpenes, and alkaloids as major phytochemical groups, a high antioxidant power measured in H-ORAC 311 ±7.63 μg/mol Trolox Equivalent/g of dry fruit, and EC 50 118.46 mg/L for the aqueous extract. The total phenols found was 20.85 ± 0.27 mg/g of dry sample of gallic acid equivalents which makes the R. adenotrichus fruit an excellent component for bacteriostatic, anti-aging, anti-wrinkle, nourishing and moisturizing formulations, and the astringent effect also allows its application to small superficial wounds on the skin. Likewise, the acidic pH of 3.55 ± 0.1 is beneficial for maintaining the cutaneous acid mantle thereby favoring the normal flora of the skin, but may be a problem for the formulation of carbomer-based gels or the incorporation of preservatives. The aqueous extract is hyperosmotic (559.66 ± 3.21 mOs/kg) and has a high electrical conductivity (285 ± 2 μS/cm) due to the presence of electrolytes and a considerable amount of sugars, according to Brix degrees (7.543° ± 0.005°). Finally, the 4% w/w aqueous extract shows an absorption of ultraviolet radiation of 25% in the wavelengths from 260 to 400 nm, by which it also could be useful for formulating compositions for sun protection.

The study of development the composition of the combination vaginal gel with hop extract

Introduction. The problem of infectious and inflammatory diseases’ treatment in gynecology still remains open. As the result of analysis of the domestic market of drugs for infectious and inflammatory diseases’ treatment in gynecology, the insufficiency of herbal drugs with local action for this pathology treatment has been identified. The Aim is composition justification of the combined plant-based drug of local action, with anti-inflammatory, antimicrobial, estrogenic, and reparative activities for complex therapy of vaginitis with different etiologies.Methods and result: during development of gel composition, natural semi-synthetic and synthetic gelatinizing agents have been used for gelatinization. In order to ensure required рН, ascorbic and lactic acids approved for medical use have been included into gel composition. Structural and mechanical properties have been investigated in experimental samples using a viscometer BROOKFIELD HB DV-2 PRO (USA). Determination of рН by potentiometric method using an ionometer (PH-150 MI) has been performed in accordance with the State Pharmacopoeia of Ukraine 1.2 .Conclusions. The introduction of ascorbic and lactic acids into gel composition at required concentrations leads to liquefaction of carbomer-based gels. Stability of gels is ensured by using xanthane gum at a concentration of 2–3% and hydroxyethyl cellulose at a concentration of 1–2%. As the result of the study the required concentration of lactic (0.1–0.2%) and ascorbic (3–4%) acids has been selected. Organoleptic, physical-chemical and rheological properties of the developed gels have been investigated.

Assessment of Lemon Balm (Melissa officinalis L.) Hydrogels: Quality and Bioactivity in Skin Cells.

The aim of the study was to design gels with lemon balm extract, assess their quality, and investigate the effect of rosmarinic acid on skin cells in normal conditions and under oxidative stress. Methods. The quantities of rosmarinic acid (RA) released from gels were evaluated by applying the HPLC technique. HaCaT cell viability was assessed by using the MTT method. ROS generation was measured using DCFH-DA dye. The results showed that the gelling material affected the release of RA content from gels. Lower and slower RA content release was determined in carbomer-based gels. After 6 hours of biopharmaceutical research in vitro, at least 4% of RA was released from the gel. The results of the biological studies on HaCaT cells demonstrated that, in the oxidative stress conditions, RA reduced intracellular ROS amounts to 28%; 0.25–0.5 mg/mL of RA increased cell viability by 10–24% and protected cells from the damage caused by H2O2. Conclusions. According to research results, it is appropriate to use a carbomer as the main gelling material, and its concentration should not exceed 1.0%. RA, depending on the concentration, reduces the amount of intracellular ROS and enhances cell viability in human keratinocytes in oxidative stress conditions.

Transdermal Evaluation of Caffeine in Different Formulations and Excipients

Background: The stratum corneum (SC) forms a difficult physical barrier for drugs to pass through the skin. Several strategies were developed to overcome this barrier. Optimization of topical drug formulations by selected excipients may facilitate the penetration of drugs through the SC into the viable skin cells and ultimately into the systemic circulation. Methods: Here, both the influence of two formulations (a classic carbomer-based gel and a novel Pluronic® lecithin organo gel (PLO gel)) and selected excipients (ethanol, propylene glycol, diethylene glycol monoethyl ether, isopropyl myristate (IPM), and water) with or without the penetration enhancer miconazole nitrate on the transdermal penetration characteristics of caffeine were determined using an in vitro Franz diffusion cell setup. Results: Higher fluxes were observed for the carbomer-based gel compared to the PLO gel. Among the commonly used excipients, IPM showed the best penetration enhancing properties, while the presence of the penetration...

A Covalently Stabilised Glucose Responsive Gel Formulation with a Carbopol ® Carrier

A novel glucose-responsive gel formulation was stabilised via covalent coupling to a carbomer resin. The gel formed between the plant lectin, concanavalin A and specific polysaccharides was stabilised to minimise leaching of gel components into the surroundings. This was required to prevent toxicity and to preserve the working mechanism of the formulation. Increased gel stability was introduced by covalently bonding amine groups present on the lysine residues of concanavalin A to carboxylic moieties on Carbopol ® 974P NF using carbodiimide chemistry. The introduction of dextran then produced a glucose-responsive formulation that transformed from gel to sol in the presence of free glucose. The rheological properties and in vitro component and insulin release of the carbomer-stabilised gel were evaluated. A decrease in viscosity over a chosen glucose concentration range was exhibited by the carbomer-based gel. The testing of such a formulation in in vitro diffusion experiments revealed that the leaching of concanavalin A from the covalently coupled gels was restricted significantly with respect to a non-coupled gel. Insulin delivery in response to glucose in the physiologically relevant glucose concentration range was demonstrated using the carbomer-stabilised gel at 37°C. The performance of this novel self-regulating drug delivery system has been improved in terms of increased gel stability with reduced component leaching.