The Effect of Polymers on Drug Release Kinetics in Nanoemulsion In Situ Gel Formulation

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

Formulation of hesperidin-loaded in situ gel for ocular drug delivery: a comprehensive study

BACKGROUND

Allergic conjunctivitis is one of the most common eye disorders. Different drugs are used for its treatment. Hesperidin is an active substance isolated from Citrus sinensis L. (Rutaceae) fruit peels, with known anti-inflammatory activity but low solubility. It was complexed with cyclodextrin and encapsulated in situ gel to extend its duration in the eye.

RESULTS

The optimized formulation comprised 1% hesperidin, 1.5% hydroxyethyl cellulose, and 16% poloxamer 407. The viscosity at 25 °C was 492 ± 82 cP, and at 35 °C it was 8875 ± 248 cP, the pH was 7.01 ± 0.03, gelation temperature was 34 ± 1.3 °C, and gelation time was 33 ± 1.2 s. There was a 66% in vitro release in the initial 2 h, with a burst effect. A lipoxygenase (LOX) inhibition test determined that hesperidin was active at high doses on leukotyrens seen in the body in allergic diseases. In cell-culture studies, the hesperidin cyclodextrin complex loaded in situ gel, BRN9-CD (poloxamer 16%, hydroxy ethyl cellulose (HEC) 1.5%), enhanced cell viability in comparison with the hesperidin solution. It was determined that BRN9-CD did not cause any irritation in the ocular tissues in the Draize test.

CONCLUSION

The findings of this study demonstrate the potential of the in situ gel formulation of hesperidin in terms of ease of application and residence time on the ocular surface. Due to its notable LOX inhibition activity and positive outcomes in the in vivo Draize test, it appears promising for incorporation into pharmaceutical formulations. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A poly-δ-decalactone (PDL) based nanoemulgel for topical delivery of ketoconazole and eugenol against Candida albicans

This study aimed to investigate the potential of poly-δ-decalactone (PDL) and a block copolymer (methoxy-poly(ethylene glycol)-b-poly-δ-decalactone (mPEG-b-PDL)) in the topical delivery of ketoconazole (KTZ) and eugenol (EUG) against Candida albicans. The nanoemulsion (NE) was studied for its significant factors and was optimized using the design of experiments (DOE) methodologies. A simple robust nanoprecipitation method was employed to successfully produce a nanoemulsion (KTZ-EUG-NE). The spherical globules exhibited rough surfaces, explaining the adsorption of mPEG-b-PDL onto PDL. The sustained drug release effects were governed by the amorphous nature of PDL. KTZ-EUG-NE was further used to develop a 1% w/v Carbopol-940-based nanoemulgel (KTZ-EUG-NE gel). The optimal rheological and spreadability properties of the developed nanoemulgel explain the ease of topical applications. Ex vivo permeation and retention studies confirmed the accumulation of KTZ-EUG-NE at different layers of the skin when applied topically. The cytotoxicity of the developed NE in human keratinocyte (HaCaT) cells demonstrated the utility of this newly explored nanocarrier in reducing the cell toxicity of KTZ. The higher antifungal activities of KTZ-EUG-NE at 19.23-fold lower concentrations for planktonic growth and 4-fold lower concentrations for biofilm formation than coarse drugs explain the effectiveness of the developed NE.

Research progress of nano delivery systems for intraocular pressure lowering drugs

Glaucoma is a chronic ocular disease characterized by optic atrophy and visual field defect. The main risk factor for glaucoma onset and progression is elevated intraocular pressure, which is caused by increased aqueous humor outflow resistance. Currently, the primary method for glaucoma therapy is the use of intraocular pressure lowering drugs. However, these drugs, when administered through eye drops, have low bioavailability, require frequent administration, and often result in adverse effects. To overcome these challenges, the application of nanotechnology for drug delivery has emerged as a promising approach. Nanoparticles can physically adsorb, encapsulate, or chemically graft drugs, thereby improving their efficacy, retention time, and reducing adverse reactions. Moreover, nanotechnology has opened up new avenues for ocular administration. This article provides a comprehensive review of nano systems for intraocular pressure lowering drugs, encompassing cholinergic agonists, β-adrenergic antagonists, α-adrenergic agonists, prostaglandin analogs, carbonic anhydrase inhibitors, Rho kinase inhibitors, and complex preparations. The aim is to offer novel insights for the development of nanotechnology in the field of intraocular pressure lowering drugs.

Quercetin-loaded nanoemulsions prevent Scopolamine-induced neurotoxicity in male rats

Quercetin (QCT) is well-known as a neuroprotective agent due to its antioxidant capacities and reinstating mitochondrial functions. Scopolamine is commonly used as a model to induce Alzheimer's disease (AD-like) symptoms. The current study develops QCT-loaded nanoemulsion (QCT-NE) accompanied by evaluating its neuro-therapeutic effectiveness against SCO-induced neurotoxicity in male rats. The QCT-NE was prepared by the spontaneous emulsification technique and characterized by using particle size, zeta potential, drug loading, in vitro drug release behavior, and stability studies. In vivo studies were done on adult Wistar rats by applying the Morris water maze (MWM) test to study spatial memory and learning. The levels of lipid peroxidation and reduced glutathione were quantitatively determined to reveal the potential mechanism of SCO-induced oxidative stress. Finally, histological studies were performed using staining techniques. The QCT-NE particle size, zeta potential, polydispersity index (PDI), and DL were obtained at 172.4 ± 16.8 nm, -29 ± 0.26 mV, 0.3 ± 0.07, and 81.42 ± 9.14 %, respectively. The QCT and more effectively QCT-NE reduced the elevation of neurobehavioral abnormalities in the MWM test in SCO-exposed rats. The results of oxidative status showed that SCO significantly could increase the LPO and decrease the GSH levels in the rat's brain. However, QCT-NE treatment was more effective than free QCT to inhibit oxidative damage and was well correlated with histopathological findings. Taken together, QCT-NE, compared to QCT, was superior in ameliorating SCO-induced AD-like symptoms due to its better neuroprotective activity and can be considered a novel supplementary therapeutic agent in AD management.

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.

Polymer-Based Self-Assembled Drug Delivery Systems for Glaucoma Treatment: Design Strategies and Recent Advances

Glaucoma has become the world's leading cause of irreversible blindness, and one of its main characteristics is high intraocular pressure. Currently, the non-surgical drug treatment scheme to reduce intraocular pressure is a priority method for glaucoma treatment. However, the complex and special structure of the eye poses significant challenges to the treatment effect and safety adherence of this drug treatment approach. To address these challenges, the application of polymer-based self-assembled drug delivery systems in glaucoma treatment has emerged. This review focuses on the utilization of polymer-based self-assembled structures or materials as important functional and intelligent carriers for drug delivery in glaucoma treatment. Various drug delivery systems, such as eye drops, hydrogels, and contact lenses, are discussed. Additionally, the review primarily summarizes the design strategies and methods used to enhance the treatment effect and safety compliance of these polymer-based drug delivery systems. Finally, the discussion delves into the new challenges and prospects of employing polymer-based self-assembled drug delivery systems for the treatment of glaucoma.

Green synthesis and characterization of silicate nanostructures coated with Pluronic F127/gelatin for triggered drug delivery in tumor microenvironments

Thermo-/pH-sensitive nanocomposites based on mesoporous silicate MCM-41 (MSNCs) derived from rice husk ash were synthesized and characterized. MSNCs were coated with thermo-/pH-sensitive Pluronic® F127 and gelatin to form MSNCs@gp nanocomposites, serving as carriers for controlled release of the anticancer drug doxorubicin (Dox). The in vitro and in vivo antitumor efficacy of MSNCs@gp-Dox against liver cancer was evaluated. Fourier-transform infrared (FTIR) spectra confirmed the silica nature of MSNCs@gp by detecting the Si-O-Si group. Under acidic microenvironments (pH 5.4) and 42 °C, MSNCs@gp-Dox exhibited significantly higher Dox release (47.33 %) compared to physiological conditions. Thermo-/pH-sensitive drug release (47.33 %) was observed in simulated tumor environments. The Makoid-Banakar model provided the best fit at pH 7.4 and 37 °C with a mean squared error of 0.4352, an Akaike Information Criterion of 15.00, and a regression coefficient of 0.9972. Cytotoxicity tests have demonstrated no significant toxicity in HepG2 cells treated with various concentrations of MSNCs@gp, while MSNCs@gp-Dox induced considerable cell apoptosis. In vivo studies in nude mice revealed effective suppression of liver cancer growth by MSNCs@gp-Dox, indicating high pharmaceutical efficacy. The investigated MSNCs@gp-based drug delivery system shows promise for liver cancer therapy, offering enhanced treatment efficiency with minimal side effects.

Design and Development of a Topical Nanogel Formulation Comprising of a Unani Medicinal Agent for the Management of Pain

The oil of the Unani medicinal herb Baboona (Matricaria chamomilla) has shown potential in the management of pain. However, predicaments such as poor skin penetration, skin sensitization, liable to degradation, and volatile nature restrict its use. Therefore, our group for the first time has developed a carrier-based delivery system to facilitate the direct application of chamomile oil to the forehead. The developed nanogel was characterized for physical parameters such as compatibility, TEM, and stability studies. Further, it was also evaluated for pH, viscosity, spread ability, and extrudability, as well as through texture analyses, in vitro studies, and skin irritation tests. The formulation was successfully developed with all the necessary attributes. The in vitro studies revealed the enhanced skin penetration of chamomile oil nanogel. The in vivo studies were also performed in chemically induced pain models, mimicking migraine. The studies show significant improvement of the pain threshold for chamomile nanogel when compared to the positive control group and the results were comparable to marketed diclofenac formulations. Finally, the encapsulation into nanogel reduced the skin irritation property. The nanogel formulation showed promising effects in the pain management of migraine.

Comparative Study of In Situ Gel Formulation Based on the Physico-Chemical Aspect: Systematic Review

In recent years, in situ gel delivery systems have received a great deal of attention among pharmacists. The in situ gelation mechanism has several advantages over ointments, the most notable being the ability to provide regular and continuous drug delivery with no impact on visual clarity. Bioavailability, penetration, duration, and maximum medication efficacy are all improved by this mechanism. Our review systematically synthesizes and discusses comparisons between three types of in situ gelling system according to their phase change performance based on the physicochemical aspect from publications indexed in the Pubmed, ResearchGate, Scopus, Elsevier, and Google Scholar databases. An optimal temperature-sensitive in situ gelling solution must have a phase change temperature greater than ambient temperature (25 °C) to be able to be readily delivered to the eye; hence, it was fabricated at 35 °C, which is the precorneal temperature. In a pH-sensitive gelling system, a gel develops immediately when the bio-stimuli come into contact with it. An in situ gelling system with ionic strength-triggered medication can also perhaps be used in optical drug-delivery mechanisms. In studies about the release behavior of drugs from in situ gels, different models have been used such as zero-order kinetics, first-order kinetics, the Higuchi model, and the Korsmeyer-Peppas, Peppas-Sahlin and Weibull models. In conclusion, the optimum triggering approach for forming gels in situ is determined by a certain therapeutic delivery application combined with the physico-chemical qualities sought.

Targeted Delivery Strategies of Herbal-Based Nanogels: Advancements and Applications

The objective of this review is to thoroughly investigate herbal nano gels as a promising drug delivery approach for the management of various chronic and acute disorders. Herbal nano gels are a novel and promising drug delivery technique, offering special benefits for better therapeutic efficacy. This review offers a comprehensive analysis of the herbal nano gels with a particular emphasis on their evaluation concerning conventional dosage forms, polymer selection criteria, drug release mechanisms, and applications. The comparison study demonstrates that herbal nano gels have different benefits over conventional dose forms. In the areas of oral administration for improved bioavailability and targeted delivery to the gastrointestinal tract, topical drug delivery for dermatological conditions, and targeted delivery strategies for the site-specific treatment of cancer, inflammatory diseases, and infections, they demonstrate encouraging results in transdermal drug delivery for systemic absorption. A promising platform for improved medication delivery and therapeutic effectiveness is provided by herbal nanogels. Understanding drug release mechanisms further contributes to the controlled and sustained delivery of herbal therapeutics. Some of the patents are discussed and the comparative analysis showcases their superiority over conventional dosage forms, and the polymer selection criteria ensure the design of efficient and optimized formulations. Herbal-based nano gels have become a potential approach for improving drug administration. They provide several advantages such as better stability, targeted delivery, and controlled release of therapeutic components. Herbal nano gels are a promising therapeutic approach with the ability to combat a wide range of conditions like cancer, wound healing and also improve patient compliance.

Formulation Development and In Vitro/In Vivo Characterization of Methotrexate-Loaded Nanoemulsion Gel Formulations for Enhanced Topical Delivery

Methotrexate-loaded oil-in-water nanoemulsion formulations were prepared using the high shear homogenization technique. A drug excipient study (ATR-FTIR) was carried out to investigate the compatibility between the drug, the polymers, and its admixtures. The thermal stability of the nanoemulsion formulations was evaluated by subjecting them to a heating and cooling cycle. The prepared nanoemulsion formulations (FNE1 to FNE6) were evaluated for particle size, PDI value, and entrapment efficiency (EE). They were analyzed for morphological information using transmission electron microscopy. The drug (methotrexate)-loaded nanoemulsion formulations (FNE2, FNE4, and FNE6) were then converted into nanoemulsion gel formulations by adding 1% chitosan (polymer) as a gelling agent. The nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6) were investigated for physicochemical parameters, viscosity, spreadability, extrudability, drug content, and skin irritation. Various penetration enhancers (olive oil, clove, and almond oil) were employed to examine the potency of the prepared nanoemulsion gel formulations. In vitro drug release, ex vivo permeation, skin drug retention, and stability tests were carried out for evaluation of the prepared nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6). The data obtained from the in vitro study were subjected to the kinetic model, and the Korsemeyer-Peppas model was best fitted to the data. The nanoemulsion gel formulation FNEG6 showed the maximum controlled drug release and followed an anomalous, non-Fickian release mechanism. The use of almond oil in the preparation of the nanoemulsion gel formulation FNEG6 helped the penetration of the drug across stratum corneum and the restructuring of the properties of skin and resulted in a higher penetration and retention of methotrexate in a deeper layer of the skin. The current study concluded that the methotrexate-loaded nanoemulsion gel formulation FNEG6 showed the best optimum release, permeation, and retention results as compared to the available oral tablets' formulations, followed by a low serum concentration and the maximum drug retention, which is beneficial in treating skin infections and reducing systemic toxicity.

Development and Characterization of Oral Raft Forming In Situ Gelling System of Neratinib Anticancer Drug Using 32 Factorial Design

Neratinib (NTB) is an irreversible inhibitor of pan-human epidermal growth factor receptor (HER-2) tyrosine kinase and is used in the treatment of breast cancer. It is a poorly aqueous soluble drug and exhibits extremely low oral bioavailability at higher pH, leading to a diminishing of the therapeutic effects in the GIT. The main objective of the research was to formulate an oral raft-forming in situ gelling system of NTB to improve gastric retention and drug release in a controlled manner and remain floating in the stomach for a prolonged time. In this study, NTB solubility was enhanced by polyethylene glycol (PEG)-based solid dispersions (SDs), and an in situ gelling system was developed and optimized by a two-factor at three-level (3²) factorial design. It was analyzed to study the impact of two independent variables viz sodium alginate [A] and HPMC K4M [B] on the responses, such as floating lag time, percentage (%) water uptake at 2 h, and % drug release at 6 h and 12 h. Among various SDs prepared using PEG 6000, formulation 1:3 showed the highest drug solubility. FT-IR spectra revealed no interactions between the drug and the polymer. The percentage of drug content in NTB SDs ranged from 96.22 ± 1.67% to 97.70 ± 1.89%. The developed in situ gel formulations exhibited a pH value of approximately 7. An in vitro gelation study of the in situ gel formulation showed immediate gelation and was retained for a longer period. From the obtained results of 3² factorial designs, it was observed that all the selected factors had a significant effect on the chosen response, supporting the precision of design employed for optimization. Thus, the developed oral raft-forming in situ gelling system of NTB can be a promising and alternate approach to enhance retention in the stomach and to attain sustained release of drug by floating, thereby augmenting the therapeutic efficacy of NTB.

Development of a Novel Methotrexate-Loaded Nanoemulsion for Rheumatoid Arthritis Treatment with Site-Specific Targeting Subcutaneous Delivery

Rheumatoid arthritis (RA) is a systemic, chronic autoimmune disease that causes disability due to progressive inflammation and destruction of the tissues around the joints. Methotrexate is mainly used to prevent the progression of joint destruction and reduce the deformity. The major challenge in treating RA with methotrexate is the systemic side effects that limit dose escalation. Hence, a novel formulation of a methotrexate-loaded nanoemulsion for subcutaneous administration was developed that aims to deliver methotrexate into the system via the lymph. The methotrexate-loaded nanoemulsion was prepared by using the aqueous-titration method. The prepared nanoemulsion was investigated for particle size, surface charge, surface morphology, entrapment efficiency, DSC (differential scanning colorimetry), drug release, hemocompatibility assay, and cytotoxicity, as well as anti-arthritic and stability studies. The vesicle size, zeta potential, PDI (polydispersity index), and entrapment efficiency of the optimized nanoemulsion were 87.89 ± 2.86 nm, 35.9 ± 0.73 mV, 0.27, and 87 ± 0.25%, respectively. The DSC study showed that the crystalline methotrexate was converted to an amorphous form and the drug was fully incorporated into the vesicles. After 72 h, the optimized nanoemulsion showed a drug release of 96.77 ± 0.63%, indicating a sustained-release dosage form. Cytocompatibility testing by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay on macrophage cell lines showed that the nanoemulsion was non-toxic. The formulation showed significant anti-arthritic activity compared to the marketed drug solution. In addition, the nanoemulsion containing methotrexate remained stable for three months when stored at a low temperature. Since the nanoemulsion containing methotrexate has excellent physicochemical properties and lowers systemic side effects by targeted delivery, it is a desirable technology for subcutaneous drug delivery.