Concentration Of Poloxamer Research Articles

Preparation and Evaluation of Poloxamer/Carbopol In-Situ Gel Loaded with Quercetin: In-Vitro Drug Release and Cell Viability Study.

Periodontitis is a severe chronic inflammatory disease, whose traditional systemic antimicrobial therapy faces great limitations. In-situ gels provide an effective solution as an emerging local drug delivery system. In this study, the novel thermosensitive poloxamer/carbopol in-situ gels loaded with 20μmol/L quercetin for the treatment of periodontitis were prepared by cold method. Thirteen batches of in-situ gels based on two independent factors (X1: poloxamer 407 and X2: carbopol 934P) were designed and optimized by the statistical method of central composite design (CCD). The transparency, pH, injectability, viscosity, gelation temperature, gelation time, elasticity modulus, degradation rate and in-vitro drug release studies of the batches were evaluated, and the percentage of drug release in the first hour, the time required for 90% drug release, gelation temperature, and gelation time were selected as dependent variables. These two independent factors significantly affected the four dependent variables (p < 0.05). The optimization result displayed that the optimized concentration of poloxamer 407 was 20.84% (w/v), and carbopol 934P was 0.5% (w/v). The optimized formulation showed a clear appearance (++), acceptable injectability (Pass), viscosity(151,798mPas), gelation temperature (36°C), gelation time (213s), preferable cell viability and cell proliferation, conformed to first-order release kinetics, and had a significant antibacterial effect. The article demonstrates the great potential of the quercetin in-situ gel as an effective treatment for periodontitis.

Optimizing chemically stable chloramphenicol in-situ gel formulations using poloxamer 407 and HPMC through full-factorial design

The primary goal was to enhance the stability and bioavailability of chloramphenicol for ophthalmic use without compromising patient comfort, such as causing blurry vision. This study employed a 2-level full factorial design to optimize the formulation, exploring different concentrations of poloxamer 407 and HPMC to achieve this objective.

Formulation of Micellar Based Water from Piper crocatum Leaves Extract Using Various Concentrations of Poloxamer 188

Formulation of Micellar Based Water from Piper crocatum Leaves Extract Using Various Concentrations of Poloxamer 188

Stabilization of gels and emulsions in the ternary water/eugenol/poloxamer 407-system: Physicochemical characterization and potential application as encapsulation platforms

The ternary system water/eugenol/poloxamer 407 can form a variety of phases that are strongly influenced by the mixture composition and the thermal history of the system. In this study, we investigated the stabilization of emulsion and gel-like systems in which eugenol is encapsulated in a poloxamer 407 matrix. Our results reveal the complex interplay between poloxamer 407 and eugenol compositions in the stabilization single-phase systems at 25ºC. Increasing concentrations of poloxamer were found to incorporate higher amounts of eugenol into emulsion-like dispersions, effectively preventing coalescence and Ostwald ripening. However, high concentrations of poloxamer 407 induced gelation of these dispersions, resulting in eugenol-loaded poloxamer 407 gels. The thermal annealing of the emulsions at 65°C for 1 h followed by equilibration at room temperature allows the extension of the compositional range for the formation of homogeneous single-phase systems providing a strategy to modulate the phase diagram of the ternary system. Additionally, the encapsulation of hydrophobic pesticides in gel-like matrices was investigated, showing uniform distribution and consistent loading capacity (approximately 0.70 % w/w) across different pesticides which may contribute to facilitate the environmental distribution and efficacy of the encapsulated molecules. This research highlights the potential of eugenol/poloxamer 407-based systems as an environmentally friendly platform for the encapsulation and delivery of hydrophobic active molecules, offering a versatile solution for various applications.

The Langmuir-Blodgett trough (Langmuir film balance) can be used to understand the stabilizer concentrations in aqueous nano- and microsuspensions

Aqueous suspensions of poorly soluble, crystalline drug particles in the sub-micron range hold the ability to regulate the drug release for a defined period of time after e.g., intramuscular, or subcutaneous administration, working as an eminent formulation strategy for the preparation of long-acting injectables. Aqueous suspensions are typically prepared by top-down approaches, e.g., wet bead media milling or high-pressure homogenization, containing the active pharmaceutical compound and surfactants and/or polymers for stabilization purposes. Currently, the screening of proper stabilizers and adequate stabilizer concentration during formulation investigations is based on a trial-and-error approach with variations in combinations, concentrations, and/or ratios. To obtain a more efficient methodology during formulation screening, the present study investigated the correlation between the surface activity of two different surfactants, i.e., poloxamer 188 and polysorbate 20, by drop profile tensiometry and Langmuir trough monolayer, and the obtained sizes of cinnarizine particles as a tool to predict the optimal surfactant concentration to prepare physical stable nano- and microsuspensions. The obtained results demonstrated that the molecular area determined as the area per surfactant molecule measured in the Langmuir trough combined with the specific surface area of the prepared suspensions could be used to predict the suitable concentration of the surfactant based upon short-term stress stability data. The results further showed that higher concentrations of poloxamer 188 were necessary to stabilize the suspensions when compared to the needed concentration of polysorbate 20. In addition, it was observed that there was a need for a slightly higher surfactant concentration when the suspensions were milled with the smallest bead size of 0.5 mm instead of larger sizes of bead (0.8 and 1.0 mm), which could not be accounted for by differences in specific surface area.

Quercetin Solid Lipid Microparticle Stability and Deposition in Rat Lungs: A Study of Surfactant Effect

This study aims to determine the effect of surfactant concentration on Quercetin SLM as a potential carrier of respiratory diseases, especially ones resulting from oxidative stress injury. Quercetin is a natural antioxidant with high activity. SLM was formed with 5% compritol 888 ATO as a lipid and different concentrations of poloxamer 188 as a surfactant. SLM was produced by a combination of emulsification and sonication involving freeze drying. SLM is characterized by organolepsis, morphology, yield, particle size, drug loading, and entrapment efficiency. The antioxidant activity of quercetin SLMs was tested using the ABTS method. SLMs are characterized as having round and smooth morphology, high yield (F1 88.53%; F2 91.44%; F3 92.87%); particle size (F1 1.81 um; F2 1.90 um; F3 1.94 um); high drug loading (F1 15.96%; F2 13.74%; F3 13.19%); and high entrapment efficiency (F1 96.53%; F2 87.94%; F3 87.48%). Increasing surfactant concentration did not produce a significant difference between formulas. Quercetin SLM showed high antioxidant activity (Quercetin 94.43%; F1 94.35%; F2 94.36%; F3 94.37%). SLM was stable at storage temperatures between 25°C and 40°C. The effect of surfactant can be seen on particle size, drug loading, and entrapment efficiency at 40°C. Results of in vivo deposition study indicated that all SLM formulas were able to deliver quercetin to the lungs. Increasing the concentration of surfactant in Quercetin SLMs made no difference to the lung deposition as confirmed by observations conducted at 1 hour and 4 hours. Quercetin SLM has the potential for lung delivery by inhalation.

Formulation and optimization of mesoporous silica loaded gel containing extract of Rosmarinus officinalis for treatment of acute wound healing

This study investigate the development and optimization of a mesoporous silica-loaded gel formulated with Rosmarinus officinalis extract, aiming to amplify wound healing capabilities by harnessing the plant's known therapeutic properties alongside the sophisticated drug delivery advantages of mesoporous silica. The formulation process entailed encapsulating the Rosmarinus officinalis extract within mesoporous silica particles before their incorporation into a gel matrix, with particular attention paid to the variable concentrations of Poloxamer 407 and HPMC K15 M to evaluate their effect on the gel's Spreadability and drug release profile. Employing a comprehensive full factorial experimental design analyzed through Design-Expert software, inclusive of ANOVA and 3D surface plotting, the investigation identified batch RF7 as the prime formulation, composed of 14 % w/v Poloxamer 407 and 1 % w/v HPMC K15 M. RF7 precisely matched the predicted Spreadability with an experimental value of 13.6 gm.cm/sec and showcased a promising Cumulative % drug release at 10 h of 87.93 %, closely aligning with a predicted 89.94 %, marking a minimal percentage error of −2.01 %. The study further validated RF7 efficacy through stability and in-vitro antibacterial activity assessments, where it demonstrated significant zones of inhibition against E. coli (22.5 ± 0.87 mm) and S. Aureus (23.4 ± 1.15 mm), nearly paralleling or outperforming the Rosmarinus officinalis extract itself and a marketed standard, Candiderma Plus. These findings, supported by rigorous statistical validation, underscore RF7 enhanced wound healing potential, marrying natural therapeutic virtues with cutting-edge drug delivery technology for a promising advancement in wound care solutions.

Impact of drug compounds mechanical/deformation properties on the preparation of nano- and microsuspensions

The preparation of nano- and microsuspensions used for long-acting injectables include several advantages, where the ability to control the particle sizes of a drug compound, e.g., wet bead media milling, to obtain a desired release rate, has shown to be highly critical. Limiting factors, making the formulation screening process time-consuming, are both the grindability of a compound to obtain the desired particle size profile as well as the addition of a suitable stabilizer at a sufficient concentration to secure a long-term physical stability. Hence, the deformation properties of three different model compounds (i.e., cinnarizine, haloperidol, and indomethacin) were investigated in the present study by quantifying fragmentation after tableting followed by the preparation of nano- and microsuspensions with two different stabilizers (polysorbate 20 and poloxamer 188) and concentrations (1, 2, or 4%), as well as bead size (ø 0.5 or 1.0 mm), during processing. It was found that cinnarizine had brittle properties, haloperidol predominantly plastic properties, and indomethacin elastic properties. Distinct particle size profiles, after milling by the dual centrifugation approach, were achieved for the three model compounds, when prepared under the same manufacturing conditions. It was possible to obtain decreased sizes of cinnarizine particles, whereas the grindability for haloperidol was more restricted due to its plastic properties. The study further showed that higher concentrations of poloxamer 188 were needed to obtain smaller sizes of particles when compared to polysorbate 20. Short-term stability studies showed an increase in sizes of particles over 49 days stored at elevated temperatures, especially for indomethacin suspensions stabilized with the highest polysorbate 20 concentration, due to increased solubility from the stabilizer vehicle as confirmed by a solubility study. Sizes of haloperidol particles remained relatively stable when stabilized with the highest concentration of polysorbate 20, even with increased solubility, indicating a higher physical stability as compared to cinnarizine and indomethacin.

Design Optimization and Evaluation of Solid Lipid Nanoparticles of Azelnidipine for the treatment of Hypertension.

Solid lipid nanoparticles (SLN) are the most promising lipid-based drug delivery utilized for enhancing the solubility, bioavailability, and therapeutic efficacy of poorly water-soluble molecules. Azelnidipine (AZN) is a calcium channel blocker widely recommended for the treatment of high blood pressure but its activity is restricted due to high lipophilicity and poor solubility in the GIT. The current research focused on the development of the SLN of AZN and thereby improving the absorption, bioavailability, and therapeutic efficacy in hypertension which is a leading cause of death worldwide. Recent patents on SLN was available as U.S. Patent,10,973,798B2, U.S. Patent 10,251,960B2, U.S. Patent 2021/0069121A1, U.S. Patent 2022/0151945A1. SLN was developed by hot melt emulsification and ultrasonication method using glyceryl monostearate (GMS) as solid lipid and Poloxamer 188 as a surfactant for the stabilization of colloidal dispersion. Box-Behnken model was utilized which predicted 13 batches in which concentration of GMS (X1), Poloxamer 188 (X2) and sonication time (X3) were considered as independent parameters. The particle size (Y1) and entrapment efficiency (Y2) were dependable parameters and optimized batch F2 showed a particle size of 166.4 nm, polydispersity index of 0.40 and zeta potential of -13.7 mV. The entrapment efficiency was observed at 86.21 %. FTIR spectra confirm the identity and compatibility with the formulation components. The differential scanning calorimetry (DSC) confirmed the absence of melting point and interpreted that AZN was entirely incorporated in the lipid matrix and transformed from crystalline to amorphous form. The ANOVA for the particle size (p-value: 0.0203), % EE (p-value: 0.0271) was found significant. The in-vitro drug release showed a sustained release pattern for about 12 h. The AZN-loaded SLN was lyophilized and intended for oral delivery. AZN-loaded SLN was developed by the hot melt emulsification method which accelerated the solubility and bioavailability and released in a sustained manner for treating hypertension.

Preparation, Characterization, Antioxidant Activities, and Determination of Anti-Alzheimer Effects of PLGA-Based DDSs Containing Ferulic Acid.

Nanoparticle (NP) systems have attracted the attention of researchers in recent years due to their advantages, such as modified release features, increased therapeutic efficacy, and reduced side effects. Ferulic acid (FA) has therapeutic effects such as anti-inflammatory, anti-Alzheimer's, antioxidant, antimicrobial, anticancer, antihyperlipidemic, and antidiabetic. In this study, FA-loaded PLGA-based NPs were prepared by a nanoprecipitation method and the effect of varying concentrations of Poloxamer 188 and Span 60 on NP properties was investigated. FA-loaded A-FA coded formulation was chosen as optimum. High encapsulation efficiency has been achieved due to the low affinity of FA to the water phase and, therefore, its lipophilic nature, which tends to migrate to the organic phase. It was determined that the release of FA from the A-FA was slower than pure FA and prolonged release in 24 h. Antioxidant and anti-Alzheimer's effects of A-FA coded NP formulation were investigated by biological activity studies. A-FA coded NP formulation showed strong DPPH free radical scavenging, ABTS cation decolorizing, and reducing antioxidant activity. Since it has both AChE inhibitor and antioxidant properties according to the results of its anti-Alzheimer activity, it was concluded that the formulation prepared in this study shows promise in the treatment of both oxidative stress-related diseases and Alzheimer's.

Application of Poloxamer for In Situ Eye Drop Modeling by Enrichment with Propolis and Balsam Poplar Buds Phenolic Compounds.

In situ poloxamer-based gels are increasingly being explored as ocular drug delivery carriers to extend the release of active substances, thereby enhancing bioavailability. The objective of this study was to develop thermally stable in situ gels incorporating balsam poplar bud extract, propolis extract, and p-coumaric acid solution and to evaluate the physicochemical parameters of these gelified eye drops. This research assessed the compatibility of poloxamer-based eye drops with active components, their physicochemical properties, stability post-sterilization and during storage, and the release profiles of the active compounds. Fifteen eye drop formulations were prepared and categorized into three groups based on active components. One of the active components was propolis extract. As an alternative to propolis, eye drops containing the plant precursor, balsam poplar bud extract, were developed. The third group's active component was p-coumaric acid, a dominant phenolic acid in propolis and balsam poplar bud extracts. The study reported phenolic contents of 76.63 CAE mg/g for propolis and 83.25 CAE mg/g for balsam poplar bud aqueous extracts, with balsam poplar bud extracts showing higher SPF values (14.0) compared to propolis (12.7), while p-coumaric acid solution exhibited the highest SPF values (25.5). All eye drops were transparent, with pH values meeting the requirements for ocular drops. Formulations containing 8-10% poloxamer 407 met the criteria for in situ gels. All formulations remained stable for 90 days. Conclusion: The study results indicate that the formulated gels possess suitable physicochemical properties, are resistant to applied autoclaving conditions, and exhibit an extended release of active compounds with an increase in poloxamer content.

Chemometrics Assisted Formulation of Glimepiride Nanosuspension for Solubility Enhancement in Diabetic Therapy—A Systematic Approach

AbstractGlimepiride (GLM), a third‐generation sulfonylurea oral hypoglycemic medication, is used to treat type II diabetes. Admittedly, it has a low bioavailability, a relatively short half‐life (t1/2), and high toxicity. To address the issue, a nanosuspension of poorly soluble GLM is designed using a Quality‐by‐Design (QbD) method, to enhance its solubility. Prospective risk factors are identified and assessed using Critical Material Attribute (CMAs) and Critical Processing Parameter (CPPs) to evaluate the targets by Taguchi orthogonal array (OA) design and to study the effects of formulation and process variables on dependent variables. The amount of Polyvinylpyrrolidone (PVP) (X2), agitation time (X5), and concentration of Poloxamer (X7) are found as significant parameters (p &lt; 0.05), and are further optimized using the Box Behnken Design as response surface methodology model. The optimized GLM nanosuspension 1) has mean particle size (PS), zeta potential, viscosity (VS), and percentage cumulative drug release (CDR%) of 258.17 nm, −25.2 mV, 1.087cPs, and 98.52%, respectively. The pattern of drug release is fitted to Non‐Fickian kinetics. The study results in an economic and efficient nano formulation with enhanced solubility.

Optimization of Pramipexole-Loaded In Situ Thermosensitive Intranasal Gel for Parkinson's Disease.

The objective of the present work was to develop and optimize an intranasal in situ gel of Pramipexole dihydrochloride for enhanced drug delivery, better patient acceptability, and possible proper treatment of Parkinson's disease. Preliminary studies were performed to select formulation components and identify key variables affecting the formulation. The optimization of the in situ gelling system of Pramipexole dihydrochloride was achieved by applying 32 full factorial design using Design-Expert® software (Stat-Ease 9.0.6 version) and taking concentrations of Poloxamer 407 (X1) and HPMC K4M (X2) as independent variables. The gelling temperature, gel strength, and percentage of drug diffused after 8 h were taken as dependent variables. The software provided an optimized formulation, with 16.50% of X1 and 0.2% of X2 with the highest desirability. An in vivo drug retention time study was performed for the optimized formulation in Wistar rats. The results of the optimization process demonstrated that the selected gel formulation exhibited desirable characteristics, including gelation near body temperature, good gel strength, suitable viscosity, and sustained drug release. The optimized formulation displayed significantly higher drug retention, lasting about 5 h, versus the plain poloxamer gel formulation. Hence, it was concluded that the optimized formulation will remain affixed at the site of application for a significant time after intranasal administration and consequently sustain the release of the drug. The optimized formulation was found to be stable during the stability studies. The developed dosage form may improve patient compliance, enhance nasal drug residence, and offer sustained drug release. However, further clinical studies are necessary to validate these findings.

Formulation development and evaluation of nasal in situ gel of promethazine hydrochloride

Objective The present work aims to develop mucoadhesive thermosensitive nasal in situ gel for Promethazine hydrochloride using quality by design (QbD) approach. It can reduce nasal mucociliary clearance (MCC) and increase residence of the drug on nasal mucosa. This might increase drug absorption to improve bioavailability of the drug as compared to oral dosage form. Significance Promethazine hydrochloride is an antiemetic drug administered by oral, parenteral and rectal routes. These routes have poor patient compliance or low bioavailability. Nasal route is a better alternative as it has large surface area, high drug absorption rate and no first pass effect. Its only limitation is short drug retention time due to MCC. By formulating a mucoadhesive in situ gel, the MCC can be reduced, and drug absorption will be prolonged. Thus, improving bioavailability. Method In-situ gel was prepared by cold method having material attributes as concentration of Poloxamer 407 (X1) as gelling agent and hydroxypropyl methyl cellulose K4M (X2) as mucoadhesive agent. Critical Quality Attributes (CQA) were gelation temperature, mucoadhesive force and ex-vivo diffusion. Central composite design (CCD) was adopted for optimization. Result Optimized formulation satisfied all the CQA significant for nasal administration. Moreover, the formulation was found to be stable in accelerated stability studies for 3 months. Conclusion It can be concluded that since the drug can easily permeate through nasal mucosa and can gain access directly in the brain without undergoing first pass metabolism along with increased residence due to mucoadhesion, mucoadhesive in situ gel has potential to increase drug bioavailability.

"Optimizing Pharmaceutical Formulations: Advancements in Nanosuspension Pre-Formulation to Enhance Solubility and Bioavailability of Active Agents"

This study aimed to enhance the bioavailability of a poorly water soluble drug by developing a nanosuspension through an innovative formulation method. The nanosuspension was produced with meticulous attention to the materials reliability and excellent quality. Nepafenac was characterised in the pre-formulation study by establishing its melting point, solubility in different solvents, organoleptic properties, and creating a calibration curve. We utilised UV spectroscopy to determine the maximum wavelength (?max) of Nepafenac and construct a standard calibration curve in ethanol. To ensure the compatibility of the medicine with the polymers (Pluronic F127 and HPMC E 5), Fourier Transform Infrared Spectroscopy (FTIR) was utilised for drug interaction analysis. The nanosuspension was produced using the solvent diffusion approach. The effect of different concentrations of Poloxamer 407 and HPMC E 5 on the formulation's effectiveness was investigated experimentally using a 32 complete factorial design. We used Response Surface Methodology (RSM) and statistical analysis to enhance the formulation concerning in vitro release, particle size, and viscosity. The pre-formulation characteristics of Nepafenac met the standards outlined in the Pharmacopoeial regulations. The maximum absorption wavelength (?max) of Nepafenac was confirmed by UV spectroscopy, and a reliable calibration curve was created. The FTIR analysis showed no chemical interaction between the medicine and polymers. RSM and experimental design indicated that Poloxamer 407 and HPMC E 5 had a substantial impact on the performance of the nanosuspension. Analysis of variance (ANOVA) confirmed the model and parameters that influence controlled drug release percentage, particle size, and viscosity. Optimal conditions for enhancing drug delivery and reducing particle size were determined by the analysis of contour and response surface plots. The optimal parameter values, as indicated in the desirability plots, closely matched the anticipated values. The experimentation confirmed the viability and effectiveness of the nanosuspension formulation generated based on the RSM findings.

The potential of starch-chitosan blends with poloxamer for the preparation of microparticles by spray-drying

Using biopolymers as wall materials in spray drying poses challenges, particularly in attaining flowability and thermal stability among their physicochemical properties. This paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer, commercially named Pluronic® F127. We aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying technique. Blends with a poloxamer concentration of 3% (w/v) demonstrated a notably higher yield, especially when compared to those with 0% and 1% concentrations. Microparticles with 3% and 5% (w/v) poloxamer displayed a narrower particle size distribution, with the 3% blend showing a superior yield attributed to arrangements of blend components that improve flowability. X-ray diffraction analysis showcased the characteristic peaks of A-type starch form, with shifts suggesting enhanced interactions between components. Microparticles with increased poloxamer content showed elevated thermal degradation temperatures, with the 3% blend registering a significant rise, opening avenues for encapsulating heat-sensitive bioactive. This study primarily focuses on the preparation and basic characterization of microparticles. It underscores the potential of blends with optimal poloxamer concentrations in microencapsulation, emphasizing further research to harness their capabilities thoroughly.

Lamotrigine-Loaded Poloxamer-Based Thermo-Responsive Sol-Gel: Formulation, In Vitro Assessment, Ex Vivo Permeation, and Toxicology Study.

The present study aimed to prepare, characterize, and evaluate a thermo-responsive sol-gel for intranasal delivery of lamotrigine (LTG), which was designed for sustained drug delivery to treat epilepsy. LTG sol-gel was prepared using the cold method by changing the concentrations of poloxamer 407 and poloxamer 188, which were used as thermo-reversible polymers. The optimized formulations of sol-gel were analyzed for clarity, pH, viscosity, gelation temperature, gelation time, spreadability, drug content, in vitro drug release studies, ex vivo permeation studies, and in vivo toxicological studies. FTIR, XRD, and DSC were performed to determine the thermal stability of the drug and polymers. The prepared formulations had a clear appearance in sol form; they were liquid at room temperature and became gel at temperatures between 31 °C and 36 °C. The pH was within the range of the nasal pH, between 6.2 and 6.4. The drug content was found to be between 92% and 94%. In vitro drug release studies indicated that the formulations released up to 92% of the drug within 24 h. The FTIR, DSC, and XRD analyses showed no interaction between the drug and the polymer. A short-term stability study indicated that the formulation was stable at room temperature and at 4-8 °C. There was a slight increase in viscosity at room temperature, which may be due to the evaporation of the vehicle. A histological study indicated that there were no signs of toxicity seen in vital organs, such as the brain, kidney, liver, heart, and spleen. It can be concluded from the above results that the prepared intranasal sol-gel for the delivery of LTG is safe for direct nose-to-brain delivery to overcome the first-pass effect and thus enhance bioavailability. It can be considered an effective alternative to conventional drug delivery for the treatment of epilepsy.

Preparation of Idebenone as a Thermosetting Nasal Gel for Better Bioavailability and Histopathological Effect

Background Idebenone is an extensively metabolized drug with poor water solubility that is used to treat Leiber’s hereditary optical neuropathy. Objective This study aims to prepare idebenone nanoemulsion as a poloxamer-based nasal gel to overcome the extensive rate of hepatic metabolism for better bioavailability and lower histopathological effect on the nasal mucosa. Methods The formulation strategy was based on eliciting mutual concentration reduction between the nanoemulsion and the carrier gel by setting their gelation temperature between 30-32°C to overcome the mucociliary dose washout. The o/w nanoemulsions rely on cremophor EL and transcutol as an emulsifying system to stabilize idebenone-loaded lemongrass oil. The spontaneous emulsification method was used to prepare nanoemulsions that were characterized by zeta sizer while the thermosensitive hydrogels were prepared using the cold method. In-vitro dissolution test and ex-vivo permeation study through excised sheep nasal mucosa were performed to evaluate the enhanced permeation ratio, rate of permeation, and permeation coefficient. The histopathological effect of direct application on sheep nasal mucosa was studied using optical microscopy to evaluate cellular toxicity. Results The formula prepared from NE1 with poloxamer 407: poloxamer188 in concentrations 10:3% w/w respectively showed almost complete drug release in 120 minutes due to complete polymers blend erosion. Furthermore, thermosensitive nano-emulgel at a temperature of gelation 31.8°C was obtained at much lower concentrations of poloxamer 407 (10%) compared to previous studies. Nanoemulsions retained their globular size below 100nm due to further gel entrapment stabilization. Conclusions Drug permeation through excised sheep nasal mucosa elicited an increase in enhanced permeation ratio to 20.3 times and other flux kinetics parameters compared to those of IDB oil dispersion. Direct cellular toxicity showed a minor inflammatory response characterized by serous infiltration of inflammatory cells and edema. In contrast, most of the epithelial cells retained their histological characteristics compared to control slides. Received: Mar. 2023 Accepted: Aug 2023 Published: Oct.2023

INCREASING THE EFFECTIVENESS OF CHITOSAN GELS TO PROTECT THE OESOPHAGEAL MUCOSA

The troublesome symptoms of gastro-oesophageal reflux disease are a serious health, medical, and social problem for patients. The main problem is gastro-oesophageal acid reflux. In this study, I investigated hydrogels that could prevent the destruction of the oesophageal mucosa. I investigated the effect of chitosan and poloxamer 407 on the protective properties of gels. The addition of chitosan to all the tested gels increased their pH and dynamic viscosity. Preparations containing 25% poloxamer 407 showed the highest pH. Texture tests showed the effect of the poloxamer concentration on the adhesion performance of the tested gels. The findings suggest that the gels can be used to treat advanced acid reflux.

Study of aqueous solutions of poloxamers by rotational viscometry and spin probe method

The aim. To study aqueous solutions of different poloxamers by spin probe method and rotational viscometry depending on the temperature and poloxamer content.&#x0D; Materials and methods. The aqueous solutions of poloxamers 188, 237, 338 and 407 were studied. The solutions were studied by rotational viscometry at different temperatures; the flow behaviour, yield stress (t0), and dynamic or apparent viscosity (η) were determined. Five spin probes differing in molecular structure, solubility, and radical localisation were introduced into the solutions. Electron paramagnetic resonance (EPR) spectra were obtained. The EPR spectra were used to determine their type and to calculate parameters.&#x0D; Results. Three factors are important for gel formation: the poloxamer type, its concentration in aqueous solution, and temperature. As the temperature of aqueous solutions of poloxamers 237, 338, and 407 increases, the rotational correlation times of fatty acid-based spin probes and the order parameters of their EPR spectra decrease. This indicates a decrease in the packing density and orderliness of the polypropylene oxide (PPO) chains in the non-polar part of the poloxamer associates, leading to an increase in the volume fraction of micelles/mesophases and promoting the formation of gels. As the temperature decreases, the opposite processes occur, leading to a gel → sol transition. At 37 °C, non-polar micelle cores could be characterised as two-dimensionally liquid and one-dimensionally solid. The rotational correlation times of the hydrophilic spin probe 4-OXO-TEMPO in 25 % aqueous solutions of poloxamers 338 and 407 are approximately constant or increasing despite an increase in the temperature. This indicates that in the polar part of the poloxamer associates, where this probe is partially localised, structural rearrangements occur with increasing temperature, which probably prevents hydrophobic hydration of the PPO chains.&#x0D; Conclusions. The rheological properties of aqueous solutions of poloxamers depend on their type, concentration, and temperature. According to the parameters of the EPR spectra of fatty acid-based spin probes, it was found that with increasing temperature, the packing density and the orderliness of the PPO chains in the non-polar part of the poloxamer associates decrease, probably leading to an increase in the volume of the micelles and causing a sol → gel transition