Preparation and in vitro, in vivo evaluations of norfloxacin-loaded solid lipid nanopartices for oral delivery

Preparation and Characterization of Polymeric Microparticles Based on Poly(ethylene brassylate-co-squaric Acid) Loaded with Norfloxacin

In recent years, increasing interest has been accorded to polyester-based polymer microstructures, driven by their promising potential as advanced drug delivery systems. This study presents the preparation and characterization of new polymeric microparticles based on poly(ethylene brassylate-co-squaric acid) loaded with norfloxacin, a broad-spectrum antibiotic. Polymacrolactone was synthesised in mild conditions through the emulsion polymerization of bio-based and renewable monomers, ethylene brassylate, and squaric acid. The microparticles were obtained using the precipitation technique and subsequently subjected to comprehensive characterization. The impact of the copolymer/drug ratio on various properties of the new system was systematically evaluated, confirming the structure of the copolymer and the encapsulation of norfloxacin. The microspheres are approximately spherical and predominantly homogeneously distributed. The average hydrodynamic diameter of the microparticles falls between 400 and 2000 nm, a decrease that is observed with the increase in norfloxacin content. All samples showed good encapsulation efficiency and drug loading capacity, with the highest values obtained for microparticles synthesised using an equal ratio of copolymer and drug. In vitro drug release results disclose that norfloxacin molecules are released in a sustained biphasic manner for up to 24 h. Antimicrobial activity was also studied, with samples showing very good activity against E. coli and moderate activity against S. aureus and E. faecalis. In addition, HDFA human fibroblast cell cultures demonstrated the cytocompatibility of the microparticles.

Perspectives on cutting-edge nanoparticulate drug delivery technologies based on lipids and their applications

Numerous nanotech arenas in therapeutic biology have recently provided a scientific platform to manufacture a considerable swath of unique chemical entities focusing on drugs. Recently, nanoparticulate drug delivery systems have emerged to deliver a specific drug to a specified site. Among all other carriers, lipids possess features exclusive to nanostructured dosage forms. The bioavailability of orally administered drugs is typically negatively affected by their poor water solubility, resulting from the unique chemical moieties introduced. Because of their unique advantages, lipid nanoparticles must become increasingly predictable as a robust delivery mechanism. The enhanced biopharmaceutical properties and significance of lipid-based targeting technologies such as liposomes, niosomes, solid lipid nanoparticles and micelles are highlighted in this review. Pharmaceutical implications of lipid nanocarriers for the transport and distribution of various therapeutic agents, such as biotechnological products and small pharmaceutical molecules, is a booming topic. Lipid nanoparticles as drug delivery systems have many appealing properties, including high biocompatibility, ease of preparation, tissue specificity, avoidance of reticuloendothelial systems, delayed drug release, scale-up feasibility, nontoxicity and targeted delivery. The use of lipid nanoparticles to enhance the transport of biopharmaceuticals is currently considered state-of-the-art. Similarly, we critically examine the upcoming guidelines that therapeutic scientists should handle.

Design and Optimization of Solid Lipid Nanoparticles Loaded with Triamcinolone Acetonide

Principles of quality by design and design of experiments are acquiring more importance in the discovery and application of new drug carriers, such as solid lipid nanoparticles. In this work, an optimized synthesis of solid lipid nanoparticles loaded with Triamcinolone Acetonide is presented using an approach that involves Stearic Acid as a lipid, soy PC as an ionic surfactant, and Tween 80 as a nonionic surfactant. The constructed circumscribed Central Composite Design considers the lipid and nonionic surfactant quantities and the sonication amplitude in order to optimize particle size and Zeta potential, both measured by means of Dynamic Light Scattering, while the separation of unentrapped drug from the optimized Triamcinolone Acetonide-loaded solid lipid nanoparticles formulation is performed by Size Exclusion Chromatography and, subsequently, the encapsulation efficiency is determined by HPLC-DAD. The proposed optimized formulation-with the goal of maximizing Zeta potential and minimizing particle size-has shown good accordance with predicted values of Zeta potential and dimensions, as well as a high value of encapsulated Triamcinolone Acetonide. Experimental values obtained from the optimized synthesis reports a dimension of 683 ± 5 nm, which differs by 3% from the predicted value, and a Zeta potential of -38.0 ± 7.6 mV (12% difference from the predicted value).

Customized 3D-printed hollow capsular device filled with norfloxacin-loaded micropellets for controlled-release delivery

Pharmacotherapy has become more focused on the personalized treatment of patients with various diseases. This field of pharmacology and pharmacogenomics focuses on developing drug delivery systems designed to address the unique characteristics of individual patients. Three-dimensional printing technology can be used to fabricate personalized drug delivery systems with desired release properties according to patient needs. Norfloxacin (NOR)-loaded micropellets (MPs) were fabricated and filled inside a stereolithography (SLA) 3D printing technology-mediated hollow capsular device in accordance with a standard size of 09 (8.4 mm length × 2.70 mm diameter). The prepared 3D-printed hollow capsular device filled with pristine NOR and NOR-loaded MPs were characterized in terms of both in vitro and in vivo means. MPs with the particle size distribution of 1540.0 ± 26 µm showed 95.63 ± 2.0% NOR content with pellet-shaped surface morphology. The in vitro release profile showed an initial lag phase of approximately 30 min, followed by the sustained release of NOR from MPs from the 3D-printed hollow capsular device. The pharmacokinetic profile showed prolonged T_max, AUC, and evidence of good RBA of NOR compared to pure NOR after a single oral administration in the experimental animal model. The overall results confirm the feasibility of SLA-mediated 3D printing technology for preparing customized solid oral unit dosage carriers that can be filled with pure NOR- and NOR-loaded MPs with controlled-release delivery features.

Perspectives and Prospective on Solid Lipid Nanoparticles as Drug Delivery Systems

Combating multiple drug resistance necessitates the delivery of drug molecules at the cellular level. Novel drug delivery formulations have made it possible to improve the therapeutic effects of drugs and have opened up new possibilities for research. Solid lipid nanoparticles (SLNs), a class of colloidal drug carriers made of lipids, have emerged as potentially effective drug delivery systems. The use of SLNs is associated with numerous advantages such as low toxicity, high bioavailability of drugs, versatility in the incorporation of hydrophilic and lipophilic drugs, and the potential for production of large quantities of the carrier systems. The SLNs and nanostructured lipid carriers (NLCs) are the two most frequently used types of nanoparticles. These types of nanoparticles can be adjusted to deliver medications in specific dosages to specific tissues, while minimizing leakage and binding to non-target tissues.

Incorporation of Antibiotics into Solid Lipid Nanoparticles: A Promising Approach to Reduce Antibiotic Resistance Emergence

Antimicrobial resistance is one of the biggest threats to global health as current antibiotics are becoming useless against resistant infectious pathogens. Consequently, new antimicrobial strategies are urgently required. Drug delivery systems represent a potential solution to improve current antibiotic properties and reverse resistance mechanisms. Among different drug delivery systems, solid lipid nanoparticles represent a highly interesting option as they offer many advantages for nontoxic targeted drug delivery. Several publications have demonstrated the capacity of SLNs to significantly improve antibiotic characteristics increasing treatment efficiency. In this review article, antibiotic-loaded solid lipid nanoparticle-related works are analyzed to summarize all information associated with applying these new formulations to tackle the antibiotic resistance problem. The main antimicrobial resistance mechanisms and relevant solid lipid nanoparticle characteristics are presented to later discuss the potential of these nanoparticles to improve current antibiotic treatment characteristics and overcome antimicrobial resistance mechanisms. Moreover, solid lipid nanoparticles also offer new possibilities for other antimicrobial agents that cannot be administrated as free drugs. The advantages and disadvantages of these new formulations are also discussed in this review. Finally, given the progress of the studies carried out to date, future directions are discussed.

Norfloxacin loaded nano-cubosomes for enhanced management of otitis externa: In vitro and in vivo evaluation

The research's goal is to design and formulate nano-structured cubosomes loaded with norfloxacin (NFX)formanagement of otitis externa. In this study, glyceryl monooleate (GMO) as lipid phase, Cremophor EL as surfactant and either Pluronic F108 or Pluronic F127 as stabilizer were the used ingredients. The nano-cubosomal formulation "CUB 1" (its dispersed phase is composed of GMO (95%), Cremophor EL (2.5%) and Pluronic F108 (2.5%)) was the best achieved one. It had small particles size (216.75 ± 2.47 nm), good polydispersity index (0.339 ± 0.012) and acceptable zeta potential (-41.2 ± 2.262 mV). Images obtained after transmission electron microscopy examination ensured nearly cubic shape of formed nanoparticles with excellent dispersibility. Moreover, micrographs of rabbit ear skin specimens examined by confocal laser microscopy ensured good permeation capability of nano-structured cubosomes.In addition, in vivoskin deposition results revealed that higher amount of NFX was deposited in the rabbit ear skin throughout the study period (10 h) compared to drug suspension. Additionally, histopathological results proved that NFX loaded cubosomes can be safely applied topically on ear skin without any signs of inflammation nor skin irritation. Accordingly, these results anticipated the nano-structured cubosomal capabilities as a favorable nano-carrier for dermal NFX delivery to external ear skin for enhancing the management of otitis externa.

Lipid Nanoparticles as Carriers for Bioactive Delivery

Nanotechnology has made a great impact on the pharmaceutical, biotechnology, food, and cosmetics industries. More than 40% of the approved drugs are lipophilic and have poor solubility. This is the major rate-limiting step that influences the release profile and bioavailability of drugs. Several approaches have been reported to administer lipophilic drugs with improved solubility and bioavailability. Nanotechnology plays a crucial role in the targeted delivery of poorly soluble drugs. Nanotechnology-based drug delivery systems can be classified as solid lipid nanoparticulate drug delivery systems, emulsion-based nanodrug delivery systems, vesicular drug delivery systems, etc. Nanotechnology presents a new frontier in research and development to conquer the limitations coupled with the conventional drug delivery systems through the formation of specific functionalized particles. This review presents a bird's eye view on various aspects of lipid nanoparticles as carriers of bioactive molecules that is, synthesis, characterization, advantage, disadvantage, toxicity, and application in the medical field. Update on recent development in terms of patents and clinical trials of solid lipid nanoparticles (SLNs) and nanostructure lipid carriers (NLCs) have also been discussed in this article.

Mixed Pluronic-Cremophor Polymeric Micelles as Nanocarriers for Poorly Soluble Antibiotics-The Influence on the Antibacterial Activity

In this work, novel polymeric mixed micelles from Pluronic F127 and Cremophor EL were investigated as drug delivery systems for Norfloxacin as model antibiotic drug. The optimal molar ratio of surfactants was determined, in order to decrease critical micellar concentration (CMC) and prepare carriers with minimal surfactant concentrations. The particle size, zeta potential, and encapsulation efficiency were determined for both pure and mixed micelles with selected composition. In vitro release kinetics of Norfloxacin from micelles show that the composition of surfactant mixture generates tunable extended release. The mixed micelles exhibit good biocompatibility against normal fibroblasts MRC-5 cells, while some cytotoxicity was found in all micellar systems at high concentrations. The influence of the surfactant components in the carrier on the antibacterial properties of Norfloxacin was investigated. The drug loaded mixed micellar formulation exhibit good activity against clinical isolated strains, compared with the CLSI recommended standard strains (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922). P. aeruginosa 5399 clinical strain shows low sensitivity to Norfloxacin in all tested micelle systems. The results suggest that Cremophor EL-Pluronic F127 mixed micelles can be considered as novel controlled release delivery systems for hydrophobic antimicrobial drugs.

Recent Advances in Oral Nano-Antibiotics for Bacterial Infection Therapy

Bacterial infections are the main infectious diseases and cause of death worldwide. Antibiotics are used to treat various infections ranging from minor to life-threatening ones. The dominant route to administer antibiotics is through oral delivery and subsequent gastrointestinal tract (GIT) absorption. However, the delivery efficiency is limited by many factors such as low drug solubility and/or permeability, gastrointestinal instability, and low antibacterial activity. Nanotechnology has emerged as a novel and efficient tool for targeting drug delivery, and a number of promising nanotherapeutic strategies have been widely explored to overcome these obstacles. In this review, we explore published studies to provide a comprehensive understanding of the recent progress in the area of orally deliverable nano-antibiotic formulations. The first part of this article discusses the functions and underlying mechanisms by which nanomedicines increase the oral absorption of antibiotics. The second part focuses on the classification of oral nano-antibiotics and summarizes the advantages, disadvantages and applications of nanoformulations including lipid, polymer, nanosuspension, carbon nanotubes and mesoporous silica nanoparticles in oral delivery of antibiotics. Lastly, the challenges and future perspective of oral nano-antibiotics for infection disease therapy are discussed. Overall, nanomedicines designed for oral drug delivery system have demonstrated the potential for the improvement and optimization of currently available antibiotic therapies.

Development of Pomegranate Extract-Loaded Solid Lipid Nanoparticles: Quality by Design Approach to Screen the Variables Affecting the Quality Attributes and Characterization

The aim of this work was to study the influence of process variables on the quality attributes of pomegranate extract loaded solid lipid nanoparticles (PE-SLNs) using Plackett-Burman design. PE-SLN formulations were prepared by hot homogenization followed by ultra-sonication technique and evaluated based on the dependent variables that were analyzed utilizing Statgraphics Centurion XV software. The lipid and surfactant (type and concentration), co-surfactant concentration, sonication time, and amplitude were selected as the independent variables (X ₁-X ₇). The dependent parameters were particle size, polydispersity index, zeta potential, entrapment efficiency, and cumulative drug release (Y ₁-Y ₅). Response surface plots, Pareto charts, and mathematical equations were generated to study the influence of independent variables on the dependent quality parameters. Out of seven variables, X ₁, X ₂, and X ₆ have the main significant (p value < 0.05) effect on the entrapment efficiency, the cumulative drug release, the polydispersity index, respectively, while particle size was mainly affected by X ₃, X ₆ and zeta potential by X ₁, X ₃, and X ₄. Consequently, this screening study revealed that stearic acid as lipid, Tween 80 as surfactant, as well as sonication with short time and high amplitude can be selected for the development of PE-SLN formulation with minimum particle size, maximum zeta potential, highest entrapment, and sustained drug release behavior. Meanwhile, concentrations of lipid, surfactant, and co-surfactant are planned to be scaled up for further optimization study. In conclusion, the Plackett-Burman design verified its influence and significance in determining and understanding both process and formulation variables affecting the quality of PE-SLNs.

Hybrid Pectin-Liposome Formulation against Multi-Resistant Bacterial Strains

This work describes the development of a gastroresistant antimicrobial formulation composed of two carriers, pectin and liposomes, intended to improve the efficiency of norfloxacin (NOR) against multi-resistant bacterial strains. The formulations showed physicochemical stability for 180 days (4 °C) in terms of size, polydispersity, and zeta potential of the vesicles, prolonging the in vitro release of NOR for 11 h. The hybrid nanocarriers improved the in vitro antimicrobial activity against different multidrug-resistant bacterial strains, such as Salmonella sp., Pseudomonasaeruginosa, E. coli and Campylobacterjejuni, in comparison to commercial NOR and liposomal suspensions. The in vivo toxicity assay in chicken embryos revealed that the hybrid systems were not toxic in any of the different parameters analyzed, a result also corroborated by the analyses of biochemical biomarkers of the chicken-embryos liver function.

Solid nanoparticles for oral antimicrobial drug delivery: a review

Most microbial infectious diseases can be treated successfully with the remarkable array of antimicrobials current available; however, antimicrobial resistance, adverse effects, and the high cost of antimicrobials are crucial health challenges worldwide. One of the common efforts in addressing this issue lies in improving the existing antibacterial delivery systems. Solid nanoparticles (SNPs) have been widely used as promising strategies to overcome these challenges. In addition, oral delivery is the most common method of drug administration with high levels of patient acceptance. Formulation into NPs can improve drug stability in the harsh gastrointestinal (GI) tract environment, providing opportunities for targeting specific sites in the GI tract, increasing drug solubility and bioavailability, and providing sustained release in the GI tract. Here, we discuss SNPs for the oral delivery of antimicrobials, including solid lipid NPs (SLNs), polymeric NPs (PNs), mesoporous silica NPs (MSNs) and hybrid NPs (HNs). We also discussed about the role of nanotechnology in IV to oral antimicrobial therapy development as well as challenges, clinical transformation, and limitations of SNPs for oral antimicrobial drug delivery.

Pomegranate extract-loaded solid lipid nanoparticles: design, optimization, and in vitro cytotoxicity study

Background

Pomegranate extract (PE) is a natural product with potent antioxidant and anticancer activity because of its polyphenols content. The main purpose of this study was to maximize the PE chemotherapeutic efficacy by loading it in an optimized solid lipid nanoparticles (SLNs) formula.

Materials and methods

The influence of independent variables, which were lipid concentration (X₁), surfactant concentration (X₂) and cosurfactant concentration (X₃), on dependent ones, which were particle size (Y₁), polydispersity index (Y₂), zeta potential (Y₃), entrapment efficiency (Y₄) and cumulative % drug release (Y₅), were studied and optimized using the Box–Behnken design. Fifteen formulations of PE-SLNs were prepared using hot homogenization followed by ultra-sonication technique. Response surface plots, Pareto charts and mathematical equations were produced to study the impact of independent variables on the dependent quality parameters. The anti-proliferative activity of the optimized formula was then evaluated in three different cancer cell lines, namely, MCF-7, PC-3 and HepG-2, in addition to one normal cell line, HFB-4.

Results

The results demonstrated that the particle sizes ranged from 407.5 to 651.9 nm and the entrapment efficiencies ranged from 56.02 to 65.23%. Interestingly, the 50% inhibitory concentration of the optimized formula had more than a 40-fold improved effect on the cell growth inhibition in comparison with its free counterpart. Furthermore, it was more selective against cancer cells than normal cells particularly in MCF-7 breast cancer cells.

Conclusion

These data proved that nanoencapsulation of PE enhanced its anticancer efficacy. Therefore, our results suggested that a PE-loaded SLNs optimized-formula could be a promising chemo therapeutic agent.

Physicochemical characterization by AFM, FT-IR and DSC and biological assays of a promising antileishmania delivery system loaded with a natural Brazilian product

The control and treatment of Leishmaniasis, a neglected and infectious disease affecting approximately 12 million people worldwide, are challenging. Leishmania parasites multiply intracellularly within macrophages located in deep skin and in visceral tissues, and the currently employed treatments for this disease are subject to significant drawbacks, such as resistance and toxicity. Thus, the search for new Leishmaniasis treatments is compulsory, and Ocotea duckei Vattimo, a plant-derived product from the biodiverse Brazilian flora, may be a promising new treatment for this disease. In this regard, the aim of this work was to develop and characterize a delivery system based on solid lipid nanoparticles (SLN) that contain the liposoluble lignan fraction (LF) of Ocotea duckei Vattimo, which targets the Leishmania phagolysosome of infected macrophages. LF-loaded SLNs were obtained via the hot microemulsion method, and their physical and chemical properties were comprehensively assessed using PCS, AFM, SEM, FT-IR, DSC, HPLC, kinetic drug release studies, and biological assays. The size of the developed delivery system was 218.85±14.2 nm, its zeta potential was -30 mV and its entrapment efficiency (EE%) was high (the EEs% of YAN [yangambin] and EPI-YAN [epi-yangambin] markers were 94.21±0.40% and 94.20±0.00%, respectively). Microscopy, FT-IR and DSC assays confirmed that the delivery system was nanosized and indicated a core-shell encapsulation model, which corroborated the measured kinetics of drug release. The total in vitro release rates of YAN and EPI-YAN in buffer (with sink conditions attained) were 29.6±8.3% and 34.3±8.9%, respectively, via diffusion through the cellulose acetate membrane of the SLN over a period of 4 h. After 24 h, the release rates of both markers reached approximately 45%, suggesting a sustained pattern of release. Mathematical modeling indicated that both markers, YAN and EPI-YAN, followed matrix diffusion-based release kinetics (Higuchi's model) with an estimated diffusion coefficient (D) of 1.3.10(-6) cm(2)/s. The LF-loaded SLNs were non-toxic to murine macrophages (20-80 μg mL(-1) range) and exerted a prominent anti-leishmanial effect (20 μg mL(-1)). These data suggest this new and well-characterized lipid nanoparticle delivery system safely and effectively kills Leishmania and warrants further clinical investigation.

Solid lipid nanoparticles with and without hydroxypropyl-β-cyclodextrin: a comparative study of nanoparticles designed for colonic drug delivery

New solid lipid nanoparticles (SLN), composed of Compritol ATO888 (C) and hydroxypropyl-β-cyclodextrin (HP), were developed in order to study a new colon-specific formulation for diclofenac sodium (D) delivery. The prepared batches differ from each other by the molecular ratio between HP and D and by the composition of the matrix. Nanoparticles composed of an exclusively lipid matrix and nanoparticles with an oligomeric and lipid matrix were compared in order to establish the effect of both components on the drug delivery tests performed. The SLN preparation method was based on the oil/water hot homogenization process. Emulsions produced were cooled at room temperature and lyophilized in order to obtain dried nanoparticles; possible damage to nanoparticle shape and size was avoided by the addition of cryoprotectants to the aqueous dispersion of nanoparticles before exsiccation. An in vitro toxicity study was performed using CaCo(2) cells to establish the safety of the prepared SLN. Data obtained showed that production method studied guarantees emulsions composed of nanosized drops which can be dried by lyophilization into SLN with a size range of 300-600 nm. In vitro and ex vivo tests demonstrated that dried SLN can be considered as colon delivery systems; however, the matrix composition as well as the presence of cryoprotectant on their surface influences the release and permeation rate of D. The in vitro toxicity studies indicated that the SLN are well tolerated.

Solid lipid nanoparticle suspension enhanced the therapeutic efficacy of praziquantel against tapeworm

Hydatid disease caused by tapeworm is an increasing public health and socioeconomic concern. In order to enhance the therapeutic efficacy of praziquantel (PZQ) against tapeworm, PZQ-loaded hydrogenated castor oil solid lipid nanoparticle (PZQ-HCO-SLN) suspension was prepared by a hot homogenization and ultrasonication method. The stability of the suspension at 4°C and room temperature was evaluated by the physicochemical characteristics of the nanoparticles and in-vitro release pattern of the suspension. Pharmacokinetics was studied after subcutaneous administration of the suspension in dogs. The therapeutic effect of the novel formulation was evaluated in dogs naturally infected with Echinococcus granulosus. The results showed that the drug recovery of the suspension was 97.59% ± 7.56%. Nanoparticle diameter, polydispersivity index, and zeta potential were 263.00 ± 11.15 nm, 0.34 ± 0.06, and −11.57 ± 1.12 mV, respectively and showed no significant changes after 4 months of storage at both 4°C and room temperature. The stored suspensions displayed similar in-vitro release patterns as that of the newly prepared one. SLNs increased the bioavailability of PZQ 5.67-fold and extended the mean residence time of the drug from 56.71 to 280.38 hours. Single subcutaneous administration of PZQ-HCO-SLN suspension obtained enhanced therapeutic efficacy against tapeworm in infected dogs. At the dose of 5 mg/kg, the stool-ova reduction and negative conversion rates and tapeworm removal rate of the suspension were 100%, while the native PZQ were 91.55%, 87.5%, and 66.7%. When the dose reduced to 0.5 mg/kg, the native drug showed no effect, but the suspension still got the same therapeutic efficacy as that of the 5 mg/kg native PZQ. These results demonstrate that the PZQ-HCO-SLN suspension is a promising formulation to enhance the therapeutic efficacy of PZQ.