Positively and negatively charged liposomes as carriers for transdermal delivery of sumatriptan: in vitro characterization

Calcium phosphates enhanced with liposomes - the future of bone regeneration and drug delivery

Effective healing and regeneration of various bone defects is still a major challenge and concern in modern medicine. Calcium phosphates have emerged as extensively studied bone substitute materials due to their structural and chemical resemblance to the mineral phase of bone, along with their versatile properties. Calcium phosphates present promising biological characteristics that make them suitable for bone substitution, but a critical limitation lies in their low osteoinductivity. To supplement these materials with properties that promote bone regeneration, prevent infections, and cure bone diseases locally, calcium phosphates can be biologically and therapeutically modified. A promising approach involves combining calcium phosphates with drug-containing liposomes, renowned for their high biocompatibility and ability to provide controlled and sustained drug delivery. Surprisingly, there is a lack of research focused on liposome-calcium phosphate composites, where liposomes are dispersed within a calcium phosphate matrix. This raises the question of why such studies are limited. In order to provide a comprehensive overview of existing liposome and calcium phosphate composites as bioactive substance delivery systems, the authors review the literature exploring the interactions between calcium phosphates and liposomes. Additionally, it seeks to identify potential interactions between calcium ions and liposomes, which may impact the feasibility of developing liposome-containing calcium phosphate composite materials. Liposome capacity to protect bioactive compounds and facilitate localized treatment can be particularly valuable in scenarios involving bone regeneration, infection prevention, and the management of bone diseases. This review explores the implications of liposomes and calcium phosphate material containing liposomes on drug delivery, bioavailability, and stability, offering insights into their advantages.

Quality by design-assisted development of D-α-tocopherol polyethylene glycol 1000 succinate-incorporated gefitinib-loaded cationic liposome(s)

Aim: Gefitinib-loaded D-α-tocopherol polyethylene glycol 1000 succinate (TPGS)-coated cationic liposomes (GEF-TPGS-LIPO+) were developed and optimized by the quality by design (QbD) approach for its potential anticancer effect. Methods/materials: Box-Behnken design (BBD) a systematic design of experiments was added to screen and optimize the formulation variables. Results: GEF-TPGS-LIPO+ shows vesicle size (210 ± 4.82 nm), polydispersity index (0.271 ± 0.002), zeta potential (22.2 ± 0.84 mV) and entrapment efficiency (82.3 ± 1.95). MTT result shows the enhanced cytotoxicity and higher intracellular drug uptake with highest and lowest levels of the reactive oxygen species and NF-κB expressions on A549 lung cancer cells, determined by fluorescence-activated cell sorting flow cytometry. Conclusion: Potential anticancer effect on A549 cells might be found due to cationic liposomal interaction with cancer cells.

Bibliometric analysis and visualization of transdermal drug delivery research in the last decade: global research trends and hotspots

Background: Transdermal delivery has become a crucial field in pharmaceutical research. There has been a proliferation of innovative methods for transdermal drug delivery. In recent years, the number of publications regarding transdermal drug delivery has been rising rapidly. To investigate the current research trends and hotspots in transdermal drug delivery, a comprehensive bibliometric analysis was performed. Methods: An extensive literature review was conducted to gather information on transdermal drug delivery that had been published between 2003 and 2022. The articles were obtained from the Web of Science (WOS) and the National Center for Biotechnology Information (NCBI) databases. Subsequently, the collected data underwent analysis and visualization using a variety of software tools. This approach enables a deeper exploration of the hotspots and emerging trends within this particular research domain. Results: The results showed that the number of articles published on transdermal delivery has increased steadily over the years, with a total of 2,555 articles being analyzed. The most frequently cited articles were related to the optimization of drug delivery and the use of nanotechnology in transdermal drug delivery. The most active countries in the field of transdermal delivery research were the China, United States, and India. Furthermore, the hotspots over the past 2 decades were identified (e.g., drug therapy, drug delivery, and pharmaceutical preparations and drug design). The shift in research focus reflects an increasing emphasis on drug delivery and control release, rather than simply absorption and penetration, and suggests a growing interest in engineering approaches to transdermal drug delivery. Conclusion: This study provided a comprehensive overview of transdermal delivery research. The research indicated that transdermal delivery would be a rapidly evolving field with many opportunities for future research and development. Moreover, this bibliometric analysis will help researchers gain insights into transdermal drug delivery research's hotspots and trends accurately and quickly.

Preparation and Optimization of Liposome Containing Thermosensitive In Situ Nasal Hydrogel System for Brain Delivery of Sumatriptan Succinate

Drug absorption is improved by the intranasal route's wide surface area and avoidance of first-pass metabolism. For the treatment of central nervous system diseases such as migraine, intranasal administration delivers the medication to the brain. The study's purpose was to develop an in situ nasal hydrogel that contained liposomes that were loaded with sumatriptan succinate (SS). A thin-film hydration approach was used to create liposomes, and a 3² factorial design was used to optimize them. The optimized liposomes had a spherical shape, a 171.31 nm particle size, a high drug encapsulation efficiency of 83.54%, and an 8-h drug release of 86.11%. To achieve in situ gel formation, SS-loaded liposomes were added to the liquid gelling system of poloxamer-407, poloxamer-188, and sodium alginate. The final product was tested for mucoadhesive strength, viscosity, drug content, gelation temperature, and gelation time. Following intranasal delivery, in vivo pharmacokinetic investigations showed a significant therapeutic concentration of the medication in the brain with a C_max value of 167 ± 78 ng/mL and an area under the curve value of 502 ± 63 ng/min·mL. For SS-loaded liposomal thermosensitive nasal hydrogel, significantly higher values of the nose-to-brain targeting parameters, that is, drug targeting index (2.61) and nose-to-brain drug direct transport (57.01%), confirmed drug targeting to the brain through the nasal route. Liposomes containing thermosensitive in situ hydrogel demonstrated potential for intranasal administration of SS.

Quality by Design-Driven Zeta Potential Optimisation Study of Liposomes with Charge Imparting Membrane Additives

Liposomal formulations, as versatile nanocarrier systems suitable for targeted delivery, have a highly focused role in the therapy development of unmet clinical needs and diagnostic imaging techniques. Formulating nanomedicine with suitable zeta potential is an essential but challenging task. Formulations with a minimum ±30 mV zeta potential are considered stable. The charge of the phospholipid bilayer can be adjusted with membrane additives. The present Quality by Design-derived study aimed to optimise liposomal formulations prepared via the thin-film hydration technique by applying stearylamine (SA) or dicetyl phosphate (DCP) as charge imparting agents. This 32 fractional factorial design-based study determined phosphatidylcholine, cholesterol, and SA/DCP molar ratios for liposomes with characteristics meeting the formulation requirements. The polynomials describing the effects on the zeta potential were calculated. The optimal molar ratios of the lipids were given as 12.0:5.0:5.0 for the SA-PBS pH 5.6 (optimised sample containing stearylamine) and 8.5:4.5:6.5 for the DCP-PBS pH 5.6 (optimised sample containing dicetyl phosphate) particles hydrated with phosphate-buffered saline pH 5.6. The SA-PBS pH 5.6 liposomes had a vesicle size of 108 ± 15 nm, 0.20 ± 0.04 polydispersity index, and +30.1 ± 1.2 mV zeta potential, while these values were given as 88 ± 14 nm, 0.21 ± 0.02, and -36.7 ± 3.3 mV for the DCP-PBS pH 5.6 vesicles. The prepared liposomes acquired the requirements of the zeta potential for stable formulations.

Voltammetric detection of sumatriptan in the presence of naproxen using Fe3O4@ZIF-8 nanoparticles modified screen printed graphite electrode

A novel electrochemical sensing platform was designed and prepared for the simultaneous detection of sumatriptan and naproxen by exploiting the prowess of the Fe₃O₄@ZIF-8 nanoparticles (NPs); as-synthesized Fe₃O₄@ZIF-8 NPs were characterized by energy-dispersive X-ray spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy and thermal gravimetric analysis. The immobilized Fe₃O₄@ZIF-8 NPs on a screen printed graphite electrode (SPGE) was evaluated electrochemically via cyclic voltammetry, linear sweep voltammetry, and differential pulse voltammetry as well as chronoamprometery means; Fe₃O₄@ZIF-8/SPGE exhibited good sensing performance for sumatriptan in a range of 0.035–475.0 µM with detection limit of 0.012 µM. Also, Fe₃O₄@ZIF-8/SPGE exhibited good sensing performance for naproxen in a range of 0.1–700.0 µM with detection limit of 0.03 µM. The modified electrode showed two separate oxidative peaks at 620 mV for sumatriptan and at 830 mV for naproxen with a peak potential separation of 210 mV which was large enough to detect the two drugs simultaneously besides being stable in the long-run with considerable reproducibility. Real sample analyses were carried out to identify the function of fabricated electrode in sensing applications wherein trace amounts of sumatriptan and naproxen could be identified in these samples.

Synergistic Effect of Acetazolamide-(2-hydroxy)propyl β-Cyclodextrin in Timolol Liposomes for Decreasing and Prolonging Intraocular Pressure Levels

The purpose of this study was to design, for the first time, a co-loaded liposomal formulation (CLL) for treatment of glaucoma including timolol maleate (TM) in the lipid bilayer and acetazolamide (Acz)-(2-hydroxy)propyl β-cyclodextrin (HPβCD) complexes (AczHP) solubilized in the aqueous core of liposomes. Formulations with TM (TM-L) and AczHP (AczHP-L), separately, were also prepared and characterized. A preliminary study comprising the Acz/HPβCD complexes and their interaction with cholesterol (a component of the lipid bilayer) was realized. Then, a screening study on formulation factors affecting the quality of the product was carried out following the design of the experiment methodology. In addition, in vitro release and permeation studies and in vivo lowering intraocular pressure (IOP) studies were performed. The results of the inclusion complexation behavior, characterization, and binding ability of Acz with HPβCD showed that HPβCD could enhance the water solubility of Acz despite the weak binding ability of the complex. Ch disturbed the stability and solubility parameters of Acz due to the fact of its competence by CD; thus, Chems (steroid derivative) was selected for further liposome formulation studies. The optimization of the lipid bilayer composition (DDAB, 0.0173 mmol and no double loading) and the extrusion as methods to reduce vesicle size were crucial for improving the physico-chemical properties and encapsulation efficiency of both drugs. In vitro release and permeation studies demonstrated that the CLL formulation showed improvement in in vitro drug release and permeation compared to the liposomal formulations with a single drug (TM-L and AczHP-L) and the standard solutions (TM-S and AczHP-S). CLL showed high efficacy in reducing and prolonging IOP, suggesting that the synergistic effect of TM and Acz on aqueous humor retention and the presence of this cyclodextrin and liposomes as permeation enhancers are responsible for the success of this strategy of co-loading for glaucoma therapy.

The technology of transdermal delivery nanosystems: from design and development to preclinical studies

Transdermal administration has gained much attention due to the remarkable advantages such as patient compliance, drug escape from first-pass elimination, favorable pharmacokinetic profile and prolonged release properties. However, the major limitation of these systems is the limited skin penetration of the stratum corneum, the skin's most important barrier, which protects the body from the insertion of substances from the environment. Transdermal drug delivery systems are aiming to the disruption of the stratum corneum in order for the active pharmaceutical ingredients to enter successfully the circulation. Therefore, nanoparticles are holding a great promise because they can act as effective penetration enhancers due to their small size and other physicochemical properties that will be analyzed thoroughly in this report. Apart from the investigation of the physicochemical parameters, a comparison between the different types of nanoparticles will be performed. The complexity of skin anatomy and the unclear mechanisms of penetration should be taken into consideration to reach some realistic conclusions regarding the way that the described parameters affect the skin permeability. To the best of the authors knowledge, this is among the few reports on the literature describing the technology of transdermal delivery systems and how this technology affects the biological activity.

Photocrosslinked, Tunable Protein Vesicles for Drug Delivery Applications

Recombinant proteins have emerged as promising building blocks for vesicle self-assembly because of their versatility through genetic manipulation and biocompatibility. Vesicles composed of thermally responsive elastin-like polypeptide (ELP) fusion proteins encapsulate cargo during assembly. However, vesicle stability in physiological environments remains a significant challenge for biofunctional applications. Here, incorporation of an unnatural amino acid, para-azido phenylalanine, into the ELP domain is reported to enable photocrosslinking of protein vesicles and tuning of vesicle size and swelling. The size of the vesicles can be tuned by changing ELP hydrophobicity and ionic strength. Protein vesicles are assessed for their ability to encapsulate doxorubicin and dually deliver doxorubicin and fluorescent protein in vitro as a proof of concept. The resulting photocrosslinkable vesicles made from full-sized, functional proteins show high potential in drug delivery applications, especially for small molecule/protein combination therapies or targeted therapies.

A Novel, Nontoxic and Scalable Process to Produce Lipidic Vehicles

Lipidic vehicles are novel industrial products, utilized as components for pharmaceutical, cosmeceutical and nutraceutical formulations. The present study concerns a newly invented method to produce lipidic vehicles in the nanoscale that is simple, nontoxic, versatile, time-efficient, low-cost and easy to scale up. The process is a modification of the heating method (MHM) and comprises (i) providing a mixture of an amphiphilic lipid and a charged lipid and/or a fluidity regulator in a liquid medium composed of water and a liquid polyol, (ii) stirring and heating the mixture in two heating steps, wherein the temperature of the second step is higher than the temperature of the first step and (iii) allowing the mixture to cool down to room temperature. The process leads to the self-assembly of nanoparticles of small size and good homogeneity, compared with conventional approaches that require additional size reduction steps. In addition, the incorporation of bioactive molecules, such as drugs, inside the nanoparticles is possible, while lyophilization of the products provides long-term stability. Most importantly, the absence of toxic solvents and the simplicity guarantee the safety and scalability of the process, distinguishing it from most prior art processes to produce of lipidic vehicles.

Continuous-Flow Production of Liposomes with a Millireactor under Varying Fluidic Conditions

Continuous-flow production of liposomes using microfluidic reactors has demonstrated advantages compared to batch methods, including greater control over liposome size and size distribution and reduced reliance on post-production processing steps. However, the use of microfluidic technology for the production of nanoscale vesicular systems (such as liposomes) has not been fully translated to industrial scale yet. This may be due to limitations of microfluidic-based reactors, such as low production rates, limited lifetimes, and high manufacturing costs. In this study, we investigated the potential of millimeter-scale flow reactors (or millireactors) with a serpentine-like architecture, as a scalable and cost-effective route to the production of nanoscale liposomes. The effects on liposome size of varying inlet flow rates, lipid type and concentration, storage conditions, and temperature were investigated. Liposome size (i.e., mean diameter) and size dispersity were characterised by dynamic light scattering (DLS); z-potential measurements and TEM imaging were also carried out on selected liposome batches. It was found that the lipid type and concentration, together with the inlet flow settings, had significant effects on the properties of the resultant liposome dispersion. Notably, the millifluidic reactor was able to generate liposomes with size and dispersity ranging from 54 to 272 nm, and from 0.04 to 0.52 respectively, at operating flow rates between 1 and 10 mL/min. Moreover, when compared to a batch ethanol-injection method, the millireactor generated liposomes with a more therapeutically relevant size and size dispersity.

Pharmacokinetic and Pharmacodynamic Evaluation of Resveratrol Loaded Cationic Liposomes for Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The destructive nature of the disease makes it difficult for clinicians to manage the condition. Hence, there is an urgent need to find new alternatives for HCC, as the role of conventional cytotoxic drugs has reached a plateau to control HCC associated mortality. Antioxidant compounds of plant origin with potential anti-tumor effect have been recognized as alternate modes in cancer treatment and chemoprevention. Resveratrol (RS) is a model natural nonflavonoid drug known for its anti-cancer activity. However, its clinical application is limited due to its poor bioavailability. The current research work aims to formulate, optimize, and characterize RS loaded cationic liposomes (RLs) for specific delivery in HCC. The optimized liposomes formulation (RL5) was spherical with a vesicle size (VS) of 145.78 ± 9.9 nm, ζ potential (ZP) of 38.03 ± 9.12 mV, and encapsulation efficiency (EE) of 78.14 ± 8.04%. In vitro cytotoxicity studies in HepG2 cells demonstrated an improved anti-cancer activity of RL5 in comparison with free RS. These outcomes were supported by a cell uptake study in HepG2 cells, in which RL5 exhibited a higher uptake than free RS. Furthermore, confocal images of HepG2 cells after 3 and 5 h of incubation showed higher internalization of coumarin 6 (C6) loaded liposomes (CL) as compared to those of the free C6. Pharmacokinetic and pharmacodynamic (prophylactic and therapeutic treatment modalities) studies were performed in N-nitrosodiethylamine (NDEA-carcinogen) induced HCC in rats. Pharmacokinetic evaluation of RL5 demonstrated increased localization of RS in cancerous liver tissues by 3.2- and 2.2-fold increase in AUC and Cmax, respectively, when compared to those of the free RS group. A pharmacodynamic investigation revealed a significant reduction in hepatocyte nodules in RL5 treated animals when compared to those of free RS. Further, on treatment with RL5, HCC-bearing rats showed a significant decrease in the liver marker enzymes (alanine transaminase, alkaline phosphatase, aspartate transaminase, total bilirubin levels, γ-glutamyl transpeptidase, and α-fetoprotein), in comparison with that of the disease control group. Our findings were supported by histopathological analysis, and we were first to demonstrate that NDEA induced detrimental effect on rat livers was successfully reversed with the treatment of RL5 formulation. These results implied that delivery of RS loaded cationic liposomes substantially controlled the severity of HCC and that they can be considered as a promising nanocarrier in the management of HCC.

Cosm-nutraceutical nanovesicles for acne treatment: Physicochemical characterization and exploratory clinical experimentation

The full exploration of the 'nutraceuticals' therapeutic potential in cosmetics has been hindered by their poor stratum corneum permeation. Therefore, the aim of the present study was to formulate a nutraceutical; quercetin, in novel vitamin C based nanovesicles (aspasomes), and to explore their beneficial effects in the treatment of acne. Aspasomes were characterized for their particle size, zeta potential, entrapment efficiency (EE%), 3-months storage stability, skin deposition/permeation, antioxidant potential, and morphology. Aspasomes antibacterial efficacy on Propionibacterium acnes using the zone of inhibition assay was also tested, whilst their safety on skin fibroblastic cells was assessed in vitro using 3T3 CCL92 cell lines. An exploratory clinical trial was conducted in acne patients, and the percentage reduction of inflammatory, non-inflammatory and total acne lesions was taken as the evaluation criterion. Results revealed that quercetin-loaded aspasomes displayed a desirable nanometer size (125-184 nm), negative charge with good storage stability, and high skin deposition reaching 40%. Aspasomes managed to preserve the antioxidant activity of quercetin, and exhibited a significantly higher antibacterial effect (15 ± 1.53 mm) against Propionibacterium acnes than quercetin alone (8.25 ± 2.08 mm), and were safe on skin fibroblastic cells. Upon clinical examination in 20 acne patients (14 females, 6 males), quercetin aspasomes exhibited reduction percentages of 77.9%, 11.8% and 55.3% for inflammatory lesions, comedones and total lesions respectively. This opens vast applications of the presented formulation in the treatment of other oxidative skin diseases, and delineates the nutraceuticals and nanoformulations prepared from natural materials as promising dermatological treatment modes.

Biophysical characterization of lutein or beta carotene-loaded cationic liposomes

The interactions between carotenoids and membrane constituents are vital for understanding the mechanism of their dynamic action. Lutein and beta-carotene were loaded separately into the bilayer of dipalmitoylphosphatidylcholine (DPPC) mixed at a molar ratio with l-α-phosphatidylethanolamine derived from sheep brain (cephalin) and stearylamine (SA) to form cationic liposomes. The molecular interaction between lutein or beta-carotene with cationic liposomes was studied using transmission electron microscopy (TEM), dynamic light scattering (DLS), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. Encapsulation efficiency (EE %) and in vitro drug release were determined. The DLS measurements confirmed the mono-dispersity of all samples. TEM results revealed that liposomal samples were oval-shaped and there was a change in their morphology and size upon encapsulation of lutein or beta-carotene. Beta-carotene was observed to adhere to the boundary surface within the liposomal assembly with external morphological alterations. EE% of lutein and beta-carotene exceeded 98.8 ± 0.3% and 87 ± 4%, respectively. Lutein doped with cationic liposomes shows better in vitro release stability (about 30%) than beta-carotene (about 45%) between the 3^rd and the 6^th hour manifested by lower leakage rate percentage of lutein which would lead to higher lutein retention. The incorporated lutein resulted in broadening and shifting of the major endothermic peak of the co-liposomes, while the incorporation of beta-carotene did not induce a noticeable shift. An FTIR study was employed to reveal structure alterations in the vesicles after the encapsulation of lutein or beta-carotene into liposomes. Encapsulation of lutein or beta-carotene into liposomes induced a change in the frequency of the symmetric and asymmetric CH₂ stretching bands in the acyl chain that may influence the order of the membrane.

The interactions between carotenoids and membrane constituents are vital for understanding the mechanism of their dynamic action.

Development and Evaluation of in-situ Nasal Gel Formulations of Nanosized Transferosomal Sumatriptan: Design, Optimization, in vitro and in vivo Evaluation

Background

Sumatriptan succinate (SUT) is a potent drug used for relieving or ending migraine and cluster headaches. SUT bioavailability is low (15%) when it is taken orally owing to its gastric breakdown and bloodstream before reaching the target arteries.

Aim

The aim of the study was to enhance SUT bioavailability through developing an intranasal transferosomal mucoadhesive gel.

Methods

SUT-loaded nanotransferosomes were prepared by thin film hydration method and characterized for various parameters such as vesicle diameter, percent entrapment efficiency (%EE), in vitro release and ex vivo permeation studies. The in-situ gels were prepared using various ratios of poloxamer 407, poloxamer 188, and carrageenan and characterized for gelation temperature, mucoadhesive strength, and rheological properties.

Results

The prepared transferosomes exhibited percent entrapment efficiencies (%EE) of 40.41±3.02 to 77.47±2.85%, mean diameters of 97.25 to 245.01 nm, sustained drug release over 6 hours, and acceptable ex vivo permeation findings. The optimum formulae were incorporated into poloxamer 407 and poloxamer 188-based thermosensitive in-situ gel using carrageenan as a mucoadhesive polymer. Pharmacokinetic evaluation showed that the prepared in-situ gel of SUT-loaded nano-transferosomes gave enhanced bioavailability, 4.09-fold, as compared to oral drug solution.

Conclusion

Based on enhancing the bioavailability and sustaining the drug release, it can be concluded that the in-situ gel of SUT-loaded nano-transferosomes were developed as a promising non-invasive drug delivery system for treating migraine.

Advanced Formulation Approaches for Ocular Drug Delivery: State-Of-The-Art and Recent Patents

The eye presents extensive perspectives and challenges for drug delivery, mainly because of the extraordinary capacity, intrinsic to this path, for drugs to permeate into the main circulatory system and also for the restrictions of the ocular barriers. Depending on the target segment of the eye, anterior or posterior, the specifications are different. The ocular route experienced in the last decades a lot of progresses related with the development of new drugs, improved formulations, specific-designed delivery and even new routes to administer a drug. Concomitantly, new categories of materials were developed and adapted to encapsulate drugs. With such advances, a multiplicity of parameters became possible to be optimized as the increase in bioavailability and decreased toxic effects of medicines. Also, the formulations were capable to easily adhere to specific tissues, increase the duration of the therapeutic effect and even target the delivery of the treatment. The ascending of new delivery systems for ocular targeting is a current focus, mainly because of the capacity to extend the normal time during which the drug exerts its therapeutic effect and, so, supplying the patients with a product which gives them fewer side effects, fewer number of applications and even more effective outcomes to their pathologies, surpassing the traditionally-used eye drops. Depending on the systems, some are capable of increasing the duration of the drug action as gels, emulsions, prodrugs, liposomes, and ocular inserts with hydrophilic properties, improving the absorption by the cornea. In parallel, other devices use as a strategy the capacity to sustain the release of the carried drugs by means of erodible and non-erodible matrices. This review discusses the different types of advanced formulations used for ocular delivery of therapeutics presenting the most recent patents according to the clinical applications.

Didodecyldimethylammonium Bromide Role in Anchoring Gold Nanoparticles onto Liposome Surface for Triggering the Drug Release

Liposomes with their capacity to anchor gold nanoparticles (AuNPs) onto their surface are used in the treatment of several pathologies such as cancer. The objective of this work was the optimization of the vesicle composition by using cationic agents in order to reinforce the anchoring process of AuNPs, and for the study of the influence of local temperature and vesicle size on drug release. A Plackett-Burman design was conducted to determine the optimal composition for the anchoring of AuNPs. A comprehensive study of the influence of lipid bilayer composition on the surface charge, size, and polydispersity index (PdI) of liposomes was carried out. Afterwards, in vitro release studies by dialysis were performed and several release parameters were evaluated as a function of temperature. Cholesterol was fixed as the rigid agent and Didodecyldimethylammonium bromide (DDAB) was selected as the cationic lipid into the liposome bilayer. Photomicrographs revealed that DDAB facilitated the anchoring of AuNPs onto the liposomal surface. The anchoring of AuNPs also enhanced the amount and rate of calcein released, especially in extruded samples, at several incubating temperatures. In addition, it was observed that both the anchoring of AuNPs and the calcein release were improved by increasing the surface of the vesicles. The contributions of liposome composition (DDAB inclusion, incubation temperature, anchoring of AuNPs) and size and surface availability of the vesicles on calcein release could be used to design improved lipid nanostructures for the controlled release of anticancer drugs.

Anionic versus cationic bilosomes as oral nanocarriers for enhanced delivery of the hydrophilic drug risedronate

Albeit its well known potency as a postmenopausal osteoporosis treatment, Risedronate suffers from poor oral bioavailability and high oral toxicity. This is the first work to assess the potential of bilosomes to address challenges of RS oral delivery. Furthermore, impact of integrating cationic moiety into bilosomes on intestinal digestability and toxicity of RS nanovesicles was first investigated in this article. Prepared formulations were optimized based on physicochemical properties, digestibility, intestinal permeation and local toxicity studies. Optimized preparations were prepared by reversed phase evaporation technique with three extrusion cycles and loaded by 10 mg/ml RS. Molar lipid to bile salt to cholesterol ratio was adjusted to 4:1:1 at pH 5. Addition of cholesterol had significantly improved bilosomes stability to digestive media. Results also revealed that permeation of anionic vesicles increased permeation by 1.5 times more than RS solution and reduced drug toxicity by 2 folds. On the other hand, Cationic bilosomes showed good stability in GIT fluids but their induced oral toxicity could limit their use. In conclusion, bilosomes are superior over liposomes regarding protection of delivery system from the damaging effect of external in digestive bile salts. In addition, it decreases toxicity issues of orally administered drugs.

Novel Findings about Double-Loaded Curcumin-in-HPβcyclodextrin-in Liposomes: Effects on the Lipid Bilayer and Drug Release

In this study, the encapsulation of curcumin (Cur) in “drug-in-cyclodextrin-in-liposomes (DCL)” by following the double-loading technique (DL) was proposed, giving rise to DCL–DL. The aim was to analyze the effect of cyclodextrin (CD) on the physicochemical, stability, and drug-release properties of liposomes. After selecting didodecyldimethylammonium bromide (DDAB) as the cationic lipid, DCL–DL was formulated by adding 2-hydroxypropyl-α/β/γ-CD (HPβCD)–Cur complexes into the aqueous phase. A competitive effect of cholesterol (Cho) for the CD cavity was found, so cholesteryl hemisuccinate (Chems) was used. The optimal composition of the DCL–DL bilayer was obtained by applying Taguchi methodology and regression analysis. Vesicles showed a lower drug encapsulation efficiency compared to conventional liposomes (CL) and CL containing HPβCD in the aqueous phase. However, the presence of HPβCD significantly increased vesicle deformability and Cur antioxidant activity over time. In addition, drug release profiles showed a sustained release after an initial burst effect, fitting to the Korsmeyer-Peppas kinetic model. Moreover, a direct correlation between the area under the curve (AUC) of dissolution profiles and flexibility of liposomes was obtained. It can be concluded that these “drug-in-cyclodextrin-in-deformable” liposomes in the presence of HPβCD may be a promising carrier for increasing the entrapment efficiency and stability of Cur without compromising the integrity of the liposome bilayer.

Stratum corneum lipid liposome-encapsulated panomycocin: preparation, characterization, and the determination of antimycotic efficacy against Candida spp. isolated from patients with vulvovaginitis in an in vitro human vaginal epithelium tissue model

In this study, a liposomal lyophilized powder formulation of panomycocin was developed for therapeutic purposes against vulvovaginal candidiasis which affects 80% of women worldwide. Panomycocin is a potent antimycotic protein secreted by the yeast Wickerhamomyces anomalus NCYC 434. This study involved the preparation of panomycocin-loaded stratum corneum lipid liposomes (SCLLs), characterization of the SCLLs, and determination of antimycotic efficacy of the formulation against Candida albicans and Candida glabrata clinical vaginal isolates in a human vaginal epithelium tissue model. The encapsulation and loading efficiencies of SCLLs were 73% and 76.8%, respectively. In transmission electron microscopy images, the SCLLs appeared in the submicron size range. Dynamic light scattering analyses showed that the SCLLs had uniform size distribution. Zeta potential measurements revealed stable and positively charged SCLLs. In Fourier transform infrared spectroscopy analyses, no irreversible interactions between the encapsulated panomycocin and the SCLLs were detected. The SCLLs retained >98% of encapsulated panomycocin in aqueous solution up to 12 hours. The formulation was fungicidal at the same minimum fungicidal concentration values for non-formulated pure panomycocin when tested on an in vitro model of vaginal candidiasis. This is the first study in which SCLLs and a protein as an active ingredient have been utilized together in a formulation. The results obtained in this study led us to conduct further preclinical trials of this formulation for the development of an effective topical anti-candidal drug with improved safety.

Development and in vitro assessment of psoralen and resveratrol co-loaded ultradeformable liposomes for the treatment of vitiligo

Vitiligo is a de-pigmenting skin disorder characterized by white patches on skin due to partial or complete loss of melanocytes. Psoralen in combination with ultraviolet-A (PUVA) acts by stimulation of melanin content and tyrosinase activity in melanocytes. Resveratrol, a sirtuin activator and a potential anti-oxidant reduce oxidative stress which is one of the triggering factors for initiation of vitiligo. Despite their therapeutic activity, weak percutaneous permeability of psoralen and poor solubility of resveratrol hinders their effective topical administration. The aim of present study is to formulate ultradeformable liposomes (UDL) co-loaded with psoralen and resveratrol for evaluation of PUVA and anti-oxidant combination in vitiligo treatment. For this purpose, UDL composed of DC-Chol, cholesterol and sodium deoxy cholate were prepared for their co-delivery. Liposomal carriers were characterized and evaluated for their efficacy using B16F10 cell line. Free radical scavenging potential was also determined for these carriers by in vitro anti-oxidant assays. Optimal co-loaded UDL with particle size ranging from 120 to 130nm, zeta potential of +46.2mV, entrapment efficiency of 74.09% (psoralen) and 76.91% (resveratrol) were obtained. Compared to control, co-loaded UDL showed significant stimulation of melanin and tyrosinase activity with major contribution of psoralen. Further, co-loaded UDL also exhibited potential free radical scavenging activity where resveratrol played a key role. Hence, psoralen and resveratrol co-loaded UDL acts in vitiligo through dual mechanisms of action viz., stimulation of melanin and tyrosinase activity as well as by anti-oxidant activity. These findings indicate that psoralen and resveratrol co-loaded UDL has the promising therapeutic potential for the treatment of vitiligo.

Cationic Lipid Content in Liposome-Encapsulated Nisin Improves Sustainable Bactericidal Activity against Streptococcus mutans

An oral infectious disease, dental caries, is caused by the cariogenic streptococci Streptococcus mutans. The expected preventive efficiency for prophylactics against dental caries is not yet completely observed. Nisin, a bacteriocin, has been demonstrated to be microbicidal against S. mutans, and liposome-encapsulated nisin improves preventive features that may be exploited for human oral health. Here we examined the bactericidal effect of charged lipids on nisin-loaded liposomes against S. mutans and inhibitory efficiency for insoluble glucan synthesis by the streptococci for prevention of dental caries. Cationic liposome, nisin-loaded dipalmitoylphosphatidylcholine/phytosphingosine, exhibited higher bactericidal activities than those of electroneutral liposome and anionic liposome. Bactericidal efficiency of the cationic liposome revealed that the vesicles exhibited sustained inhibition of glucan synthesis and the lowest rate of release of nisin from the vesicles. The optimizing ability of cationic liposome-encapsulated nisin that exploit the sustained preventive features of an anti-streptococcal strategy may improve prevention of dental caries.

Deformability properties of timolol-loaded transfersomes based on the extrusion mechanism. Statistical optimization of the process

The purpose of this work was to analyze the deformability properties of different timolol maleate (TM)-loaded transfersomes by extrusion. This was performed because elastic liposomes may contribute to the elevation of amount and rate of drug permeation through the corneal membrane. This paper describes the optimization of a transfersome formulation by use of Taguchi orthogonal experimental design and two different statistical analysis approaches were utilized. The amount of cholesterol (F1), the amount of edge-activator (F2), the distribution of the drug into the vesicle (F3), the addition of stearylamine (F4) and the type of edge-activator (F5) were selected as causal factors. The deformability index, the phosphorous recovery, the vesicle size, the polydispersity index, the zeta potential and percentage of drug entrapped were fixed as the dependent variables and these responses were evaluated for each formulation. Two different statistical analysis approaches were applied. The better statistical approach was determined by comparing their prediction errors, where regression analysis provided better optimized responses than marginal means. From the study, an optimized formulation of TM-loaded transfersomes was prepared and obtained for the proposed ophthalmic delivery for the treatment of open angle glaucoma. It was found that the lipid to surfactant ratio and type of surfactant are the main key factors for determining the flexibility of the bilayer of transfersomes. From in vitro permeation studies, we can conclude that TM-loaded transfersomes may enhance the corneal transmittance and improve the bioavailability of conventional TM delivery.

In vitro skin permeation and anti-atopic efficacy of lipid nanocarriers containing water soluble extracts of Houttuynia cordata

OBJECTIVE

The aims of this work are to enhance the in vitro skin permeation of Houttuynia cordata (water-soluble extract of H. cordata; HCWSE) and to boost the efficacy of HCWSE against atopic dermatitis (AD) - like skin lesion in hairless mice using lipid nano-carriers (liposome and cubosome).

METHODS

HCWSE was obtained by a hot water extraction. Monoolein cubosomal suspension containing HCWSE and egg phosphatidylcholine liposomal suspension containing the same was prepared by a sonication and a film hydration method, respectively.

RESULTS

The lipid nano-carriers, especially cubosome, enhanced the in vitro skin permeation of HCWSE. The inhibitory effects of HCWSE-containing lipid carrier suspensions on the development of 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD-like skin lesion in hairless mice were investigated by observing appearance of skin surface, serum immunoglobulin E (IgE) level and cytokine expression. HCWSE-containing preparations suppressed IgE production and interleukin 4 expression, whereas they promoted interferon gamma expression. The order of lymphocyte (B-cell, Th1 cell and Th2 cell) modulating effect was HCWSE-containing cubosomal suspension > HCWSE-containing liposomal suspension > HCWSE solution in phosphate buffered saline, indicating that the cubosomal suspension, among the preparations, was the most efficacious in inhibiting the development of DNCB-induced AD-like skin lesion.

CONCLUSION

It is believed that the cubosomal suspension containing HCWSE would be an efficacious preparation for the treatment of AD.

Engineered nanoparticulate drug delivery systems: the next frontier for oral administration?

For the past few decades, there has been a considerable research interest in the area of oral drug delivery using nanoparticle (NP) delivery systems as carriers. Oral NPs have been used as a physical approach to improve the solubility and the stability of active pharmaceutical ingredients (APIs) in the gastrointestinal juices, to enhance the intestinal permeability of drugs, to sustain and to control the release of encapsulated APIs allowing the dosing frequency to be reduced, and finally, to achieve both local and systemic drug targeting. Numerous materials have been used in the formulation of oral NPs leading to different nanoparticulate platforms. In this paper, we review various aspects of the formulation and the characterization of polymeric, lipid, and inorganic NPs. Special attention will be dedicated to their performance in the oral delivery of drug molecules and therapeutic genes.