Eplerenone nanoemulsions for treatment of hypertension. Part II: Physical stability assessment and in vivo study

Nanoemulsions of betulinic acid stabilized with modified phosphatidylcholine increase the stability of the nanosystems and the drug's bioavailability

Betulinic acid (BA) is a natural compound with significant potential for treating various diseases, including cancer and AIDS, and possesses additional anti-inflammatory and antibacterial properties. However, its clinical application is limited because of its low solubility in water, which impairs its distribution within the body. To overcome this challenge, nanoemulsions have been developed to improve the bioavailability of such poorly soluble drugs. This study investigated modified phosphatidylcholine (PC), where some fatty acids were replaced with conjugated linoleic acid (CLA) to stabilize BA nanoemulsions. The modified PC was used to prepare nanoemulsions with droplet sizes of up to 45 nanometers. These nanoemulsions maintained stability for 60 days at room temperature (25°C±2°C) and under refrigeration (5°C±1°C), with no signs of instability. Nanoemulsions stabilized with CLA-modified PC achieved a higher drug encapsulation rate (93.5±4.3 %) than those using natural PC (82.8±4.2 %). In an in vivo model, both nanoemulsion formulations significantly increased BA absorption, with CLA-modified PC enhancing absorption by 21.3±1.3 times and natural PC by 20±2.3 times compared to the free drug. This suggests that nanoemulsions with modified PC could improve the stability and efficacy of BA in clinical applications.

Prolonged Release Niosomes For Ocular Delivery of Loteprednol: Ocular Distribution Assessment on Dry Eye Disease Induced Rabbit Model

Loteprednol etabonate (LE) is a topical corticosteroid for the symptomatic management of ocular conditions, encompassing both allergic and infectious etiologies. Owing to the dynamic and static barriers of the eye, LE exhibits significantly low bioavailability, necessitating an increase in the frequency of drug administration. The objective of this study is to overcome the limitations by developing niosomal systems loaded with LE. Design of Experiments (DoE) approach was used for the development of optimal niosome formulation. The optimal formulation was characterized using DLS, FT-IR, and DSC analysis. In vitro and ex vivo release studies were performed to demonstrate drug release patterns. After that HET-CAM evaluation was conducted to determine safety profile. Then, in vivo studies were carried out to determine therapeutic activity of niosomes. Zeta potential (ZP), particle size, polydispersity index (PI), and encapsulation efficacy (EE) were -33.8 mV, 89.22 nm, 0.192, and 89.6%, respectively. Medicated niosomes had a broad distribution within rabbit eye tissues and was absorbed by the aqueous humor of the bovine eye for up to 6 h after treatment. Cumulative permeated drug in the bovine eye and rabbit eye were recorded 52.45% and 54.8%, respectively. No irritation or hemorrhagic situation was observed according to the results of HET-CAM study. Thus, novel LE-loaded niosomal formulations could be considered as a promising treatment option for the dry-eye-disease (DED) due to enhanced bioavailability and decreased side effects.

An Updated Review on Nanoemulsion: Factory for Food and Drug Delivery

BACKGROUND

A nanoemulsion is a colloidal system of small droplets dispersed in another liquid. It has attracted considerable attention due to its unique properties and various applications. Throughout this review, we provide an overview of nanoemulsions and how they can be applied to various applications such as drug delivery, food applications, and pesticide formulations.

OBJECTIVE

This updated review aims to comprehensively overview nanoemulsions and their applications as a versatile platform for drug delivery, food applications, and pesticide formulations.

METHODS

Research relevant scientific literature across various databases, including PubMed, Scopus, and Web of Science. Suitable keywords for this purpose include "nanoemulsion," "drug delivery," and "food applications." Ensure the search criteria include recent publications to ensure current knowledge is included.

RESULTS

Several benefits have been demonstrated in the delivery of drugs using nanoemulsions, including improved solubility, increased bioavailability, and controlled delivery. Nanoemulsions have improved some bioactive compounds in food applications, including vitamins and antioxidants. At the same time, pesticide formulations based on nanoemulsions have also improved solubility, shelf life, and effectiveness.

CONCLUSION

The versatility of nanoemulsions makes them ideal for drug delivery, food, and pesticide formulation applications. These products are highly soluble, bioavailable, and targeted, providing significant advantages. More research and development are required to implement nanoemulsion-based products on a commercial scale.

Nanoemulsions as a Promising Carrier for Topical Delivery of Etodolac: Formulation Development and Characterization

This research primarily focuses on the development of innovative topical nanoemulsions for etodolac, aimed at surmounting its inherent limitations. The preparation of etodolac nanoemulsions is accomplished through a combination of high shear homogenization and ultrasonication methods. The optimization of the formulation components is systematically conducted using the design of experiments methodology. The droplet size (DS), polydispersity index (PDI), and zeta potential (ZP) of the optimized formulation were assessed using the differential light scattering (DLS) technique. Surface morphology examinations were conducted using electron microscopy, while interactions between excipients and the drug were analyzed through FTIR analysis. Additionally, in vitro release and ex vivo permeability studies were carried out. Furthermore, anti-inflammatory activity was evaluated in the context of a carrageenan-induced paw edema model in rats. The DS, PDI, and ZP of the optimal formulation were 163.5 nm, 0.141, and -33.1 mV, respectively. The in vitro release profile was assessed as a sustained release by following a non-Fickian drug transport. The flux of etodolac nanoemulsions and coarse dispersions were 165.7 ± 11.7 µg/cm2 h and 59.7 ± 15.2 µg/cm2 h, respectively. Enhanced edema inhibition was observed at 13.4%, 36.5%, and 50.65% for the 6th, 8th, and 24th hours, respectively. Taken together, these results confirmed that nanoemulsions are promising carriers for the topical delivery of etodolac.

Eplerenone repurposing in management of chorioretinopathy: Mechanism, nanomedicine-based delivery applications and future trends

Chronic central serous chorioretinopathy (CSCR) is an ocular threatening disease, a common cause of central vision loss, affecting the posterior pole of the eye. Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist that used primarily to treat hypertension. Recently, it has shown many benefits in modifying the physio-pathological processes occurring upon stimulation of renin-angiotensin aldosterone system at the ocular level. In CSCR treatment, several clinical studies and case reports prove the efficacy and safety of EPL. However, some setbacks for such studies as a relatively small number of participants and short follow-up periods. This review article is intended to describe theories about the nature and classification of CSCR and recapitulate EPL therapeutic benefits as selective mineralocorticoid receptor antagonist in the treatment of CSCR. Furthermore, a literature survey on clinical studies discussing the results of use of EPL in treatment of CSCR. In addition, EPL therapeutic formulations that were developed up to date, and the future potential delivery systems will be suggested.

Lipid-based nano-formulation platform for eplerenone oral delivery as a potential treatment of chronic central serous chorioretinopathy: in-vitro optimization and ex-vivo assessment

PURPOSE

Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist used for treatment of chronic central serous chorioretinopathy which characterized by accumulation of subretinal fluid causing a localized area of retinal detachment. unfortunately, EPL suffers from poor oral bioavailability due to poor aqueous solubility in addition to high hepatic first pass metabolism.

METHOD

Aiming to improve its oral bioavailability, EPL-loaded nanostructured lipid carriers (NLCs) were prepared by the emulsification solvent evaporation method and in-vitro evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). A D-optimal design was used for study the effect of liquid lipid to solid lipid ratio, surfactant type and percentage on PS, PDI, EE%, and for data optimization. The optimized EPL-loaded NLCs system was further evaluated using in-vitro drug release and ex-vivo permeation studies through rabbit intestine in comparison to EPL aqueous suspension. The physicochemical properties of the drug in the optimized system were further examined using FT-IR and X-ray diffraction studies.

RESULTS

The resultant NLCs showed small PS (100.85-346.60 nm), homogenous distribution (0.173-0.624), negatively charged particles (ZP -20.20 to -36.75 mV), in addition to EE% (34.31-70.64%). The optimized EPL-loaded NLCs system with a desirability value of 0.905 was suggested through the Design expert® software, containing liquid to solid lipid ratio (2:1) in presence of 0.43%w/v Pluronic® F127 as a surfactant. The optimized EPL-loaded NLCs system showed a PS of 134 nm and PDI of 0.31, in addition to high EE% (76 ± 6.56%w/w), and ZP (-32.37 mV). The ex-vivo permeation study showed two-fold higher drug permeation through rabbit intestine compared to that from the aqueous drug suspension after 24 h, confirming the ability of optimized EPL-loaded NLCs system as successful oral targeting delivery carrier.

CONCLUSION

Our results pave the way for a new oral nanotherapeutic approach toward CSCR treatment. In-vivo study is currently under investigation.

Eplerenone nanocrystals engineered by controlled crystallization for enhanced oral bioavailability

Poor aqueous solubility of eplerenone (EPL) is a major obstacle to achieve sufficient bioavailability after oral administration. In this study, we aimed to develop and evaluate eplerenone nanocrystals (EPL-NCs) for solubility and dissolution enhancement. D-optimal combined mixture process using Design-Expert software was employed to generate different combinations for optimization. EPL-NCs were prepared by a bottom-up, controlled crystallization technique during freeze-drying. The optimized EPL-NCs were evaluated for their size, morphology, thermal behavior, crystalline structure, saturation solubility, dissolution profile, in vivo pharmacokinetics, and acute toxicity. The optimized EPL-NCs showed mean particle size of 46.8 nm. Scanning electron microscopy revealed the formation of elongated parallelepiped shaped NCs. DSC and PXRD analysis confirmed the crystalline structure and the absence of any polymorphic transition in EPL-NCs. Furthermore, EPL-NCs demonstrated a 17-fold prompt increase in the saturation solubility of EPL (8.96 vs. 155.85 µg/mL). The dissolution rate was also significantly higher as indicated by ∼95% dissolution from EPL-NCs in 10 min compared to only 29% from EPL powder. EPL-NCs improved the oral bioavailability as indicated by higher AUC, C_max, and lower T_max than EPL powder. Acute oral toxicity study showed that EPL-NCs do not pose any toxicity concern to the blood and vital organs. Consequently, NCs prepared by controlled crystallization technique present a promising strategy to improve solubility profile, dissolution velocity and bioavailability of poorly water-soluble drugs.

Effective Ocular Delivery of Eplerenone Using Nanoengineered Lipid Carriers in Rabbit Model

Background

Eplerenone (Epl) is a selective mineralocorticoid-receptor antagonist used for chronic central serous chorioretinopathy treatment. Our goal was to enhance the corneal performance of Epl-loaded nanostructured lipid carriers (NLCs) through surface modification using different coating polymers.

Methods

Epl-loaded modified NLCs (Epl-loaded MNLCs) were prepared by coating the surface of Epl-loaded NLCs using different polymers, namely hyaluronic acid, chitosan oligosaccharide lactate, and hydrogenated collagen. A 3¹×4¹ full factorial design was used to evaluate the effect of the surface modification on the properties of the prepared systems. Selected optimal Epl-loaded MNLCs were further evaluated for in vitro drug release, morphology, pH, rheological properties, corneal mucoadhesion, irritation, and penetration.

Results

Epl-loaded MNLCs were successfully prepared with high drug-entrapment efficiency and nanosized particles with low size distribution. Transmission electron microscopy revealed nanosized spherical particles surrounded by a coating layer of the surface modifier. The pH, refractive index, and viscosity results of the Epl-loaded MNLCs confirmed the ocular compatibility of the systems with no blurring of vision. The safety and ocular tolerance of the optimal MNLCs were confirmed using the hen’s egg test on chorioallantoic membrane and by histopathological evaluation of rabbit eyes treated with the optimal systems. Confocal laser-scanning microscopy of corneal surfaces confirmed successful transcorneal permeation of the Epl-loaded MNLCs compared to the unmodified Epl-loaded NLCs, revealed by higher corneal fluorescence intensity at all time intervals.

Conclusion

Overall, the results confirmed the potential of Epl-loaded MNLCs as a direct approach for Epl ocular delivery.

Nanoemulsion: A Novel Drug Delivery Approach for Enhancement of Bioavailability

BACKGROUND

Poor bioavailability and solubility of drugs in aqueous phase are the most important problems of newly developed chemical entities that can be improved by nanoemulsion.

OBJECTIVES

BCS class II and IV which are poorly soluble in water demonstrate various problems in conventional dosage forms. For the improvement of solubility, bioavailability and getting the best therapeutic effect of poorly soluble drugs nanoemulsion is the best solution.

METHODS

Nanoemulsion are thermodynamically unstable isotropic system with droplet size 1-100 nm in which two immiscible fluids are combined together to form one phase by using an emulsifying agent. Nanoemulsion can be designed to promote the bioavailability of API by trapping them inside.

RESULTS

Nanoemulsion can be developed in many dosage forms such as oral, parenteral, topical, ophthalmic dosage form in large scale using common operation at a very low cost. Large range of lipophilic drugs can be easily incorporated in nanoemulsion.

CONCLUSION

In this review, attention is focused on the type of nanoemulsions, their advantages over other dosage form, method for their preparation, characterization, applications and patents in various fields.

Physical and chemical stability of β-carotene nanoemulsions during storage and thermal process

Nanotechnology has become an option for the encapsulation of compounds, such as carotenoids. However, for the incorporation in to food, it is necessary to develop nanometric systems that are stable under the different conditions to which the food is submitted during its production, transport, and storage. Thus, with the intent to develop a stable nanoemulsion formulation for food application, the physical and chemical stability of β-carotene nanoemulsions after thermal treatments and storage under different conditions, were investigated in this work. The β-carotene nanoemulsions were formulated with corn oil, by applying high-pressure homogenization, with an average size in the 300 nm range, which is within the appropriate scale for industrial preparations, such as foods and cosmetics. The nanoemulsion droplets had negative charge (more than -25 mV) and monodisperse profile. The sample were pasteurized, sterilized, and stored at 4, 25, and 37 °C in the presence and absence of light for up to 90 days. Following the heat treatments and storage, the nanoemulsions showed no evidence of physical destabilization, retaining 70-80% of the carotenoid after the pasteurization and sterilization processes, and 70% when stored at 4 °C without light, respectively. Overall, our findings provide new information about the physical and chemical stability of β-carotene nanoemulsions during traditional thermal processes and environmental conditions.