Nanoparticles and the new era in diabetes management

Diabetes mellitus (DM) has been known to mankind for more than 2000 years. DM is a group of metabolic disorder characterized by a complete lack of insulin, a relative lack of insulin, or insulin resistance. The increase in prevalence of DM is due to three influences: lifestyle, ethnicity, and age. Current challenges in diabetes management include: optimizing the use of the already available therapies to ensure adequate glycemic, blood pressure, and lipid control and to reduce complications. At present several researches have been focusing on new management options for diabetes. Among these options the use of nanomedicine is becoming an eye catching and most promising. The aim of the present review is to provide brief overview of the applications of nanoparticles (NPs) in diabetes management. The development of improved oral insulin administration is very essential for the treatment of DM to overcome the problem of daily subcutaneous injections. In diabetic patients oral administration of insulin can be beneficial not only to alleviate the pain and trauma caused by injections, but it can also mimic the physiological fate of insulin as well. It has been found that NPs of chitosan, calcium pectinate zinc oxide, alginate, casein and different polymers have been used as a carrier for oral insulin delivery. Buccal administration of insulin with absorption enhancers showed a maximum 12% pharmacological activity. Biodegradable Polymeric NPs for parenteral insulin delivery have also been used, where the insulin matrix surrounded by the nanoporous membrane containing grafted glucose oxidase. A rise in blood glucose level triggers a change in the surrounding nanoporous membrane, resulting in biodegradation and subsequent insulin delivery. Inhalable, polymeric NP-based drug delivery systems have also been tried earlier for the treatment of tuberculosis and cardiovascular disease treatment. Such approaches can be directed toward insulin delivery through inhalable NPs. All previous studies resulted in post treatment accumulation of the NPs in skin and eyes. These drug delivery technologies are in various stages of research and development. The medical applications for nanotechnology are enormous and could give medicine, including the treatment of diabetes, an entirely new outlook

Engineer Micro- and Nano-Sized Polymeric Particles for Drug Delivery Using Advanced Multivariate Statistical Tools

Particulate drug delivery systems are gaining considerable attention in recent years due to increasing advantages for an effective delivery of therapeutics. Application of advanced particle engineering technologies in polymeric drug delivery systems has shown to improve the efficacy of a drug substance by maintaining stable levels in the blood when compared to traditional parenteral drug products. However, development of these products is a complex multifaceted process with numerous challenges. Formulation development scientists need to comprehend and control a range of unit manufacturing operations along with the formulation composition for a successful product. Therefore, the objective of this project is to study the development of advanced micro-and nano-sized drug products with minimum number of experiments using multivariate statistical tools. Chapter 1 provides background and literature on various polymers used in drug delivery and particle engineering technologies to manufacture micro- and nano-sized drug products. It also provides a comprehensive overview on various multivariate statistical tools that could be applied in product development. Chapter 2 compares the capabilities of principal component regression (PCR) and multiple linear regression (MLR) to model and predict the impact of formulation and process parameters on the metronidazole benzoate–ethyl cellulose microsponge particle properties. The observations imply that MLR models showed relatively better predictability than PCR. Chapter 3 reports the aerosolization of sildenafil citrate loaded polymeric microparticles engineered using multivariate statistical tools by spray-drying (SD) and spray freeze-drying (SFD) processes. Particles engineered by both SD and SFD demonstrate good aerosolization properties. However, particles engineered by SD demonstrated relatively superior aerodynamic characteristics than SFD Chapters 4 and 5 reports gelatin nanoparticles (GNPs) engineered by desolvation using multivariate statistical tools. About 20-40% of the low molecular weight (25 kD) fraction could be eliminated by a desolvating ‘as is’ gelatin with acetone. Studies demonstrated statistically significant (p\u3c0.05) roles of gelatin solution pH and incubation times on the size and size distribution of the nanoparticles prepared by desolvation. Irrespective of gelatin grades, desolvated gelatins produced GNPs with significantly (p=0.0287) lower size when compared to ‘as is’ gelatins. It is highly recommended to use freshly prepared gelatin solution to attain GNPs of reproducible size. Overall, these experimental findings show that selection of statistical design for particle engineering is formulation and process dependent. Reproducibility of protein-based nanoparticles are greatly influenced by starting material properties and sample composition prior to synthesis. This study is anticipated to lay foundation for further exploration to develop a highly-controlled processing technologies to engineer polymeric particulate drug delivery systems

INHALABLE NANOCOMPOSITES AND ANTICANCER AGENTS FOR CANCER THERAPY

Cancer is designated as the leading cause of mortality worldwide and lung cancer is responsible for nearly 30% of all cancer related deaths. Over the last few decades mortality rates have only marginally increased and rates of recurrence remain high. These factors, among others, suggest the need for more innovative treatment modalities in lung cancer therapy. Targeted pulmonary delivery is well established for treating pulmonary diseases such as asthma and provides a promising platform for lung cancer therapy. Increasing local deposition of anticancer agents (ACAs) and reducing systemic exposure of these toxic moieties could lead to better therapeutic outcomes and higher quality of life for lung cancer patients receiving such harsh chemotherapy regimens. In this work, a novel lung cancer treatment modality is presented wherein ACAs are incorporated into inhalable dry powder composites for targeted delivery to the pulmonary tract. Additionally, nanoparticles were added to inhalable composites to increase the therapeutic potential of these unique materials. A variety of dry powder composites were formulated via spray drying and the physicochemical properties of the resulting systems were characterized. Additionally, the performance of the cargo incorporated into these composites was evaluated in order to insure the activity of the components after release from the inhalable dry powders. The aerodynamic performance of the dry powder systems was evaluated with the Next Generation Impactor® to determine if these materials were suitable for inhalation purposes. Iron oxide (Fe3O4) magnetic nanoparticles were synthesized and incorporated into dry powders to examine the feasibility of administering these materials to the lungs for remotely actuated hyperthermia. Remote heating studies were performed on the nanoparticles released from these composites using a custom Taylor Winfield® alternating magnetic field source, and in vitro hyperthermia studies were performed using advanced multicellular spheroid cell culture models. These studies elicited the effectiveness of these systems on physiologically relevant models. In addition to the iron oxide composites, dry powders were formulated with two common ACAs, cisplatin and erlotinib, for inhalable chemotherapy. The activity of the drugs released from these composites was evaluated on the human pulmonary lung cancer cell lines A549 and H358 and compared with the free form of the drugs in order to evaluate the effectiveness of these therapies. Finally, responsive hydrogel nanoparticles (HNPs) that contain the ability to respond to environmental changes in pH were synthesized and evaluated as responsive drug carriers. The response of these particles to pH was evaluated and their stability was examined before and after inclusion into dry powder composites. Overall, inhalable dry powder nanocomposites are promising materials for innovative lung cancer treatment modalities and have the potential to provide a safer and more effective option for addressing this devastating disease

Inhalable Formulation Based on Lipid-Polymer Hybrid Nanoparticles for the Macrophage Targeted Delivery of Roflumilast

Here, novel lipid-polymer hybrid nanoparticles (LPHNPs), targeted to lung macrophages, were realized as potential carriers for Roflumilast administration in the management of chronic obstructive pulmonary disease (COPD). To achieve this, Roflumilast-loaded fluorescent polymeric nanoparticles, based on a polyaspartamide-polycaprolactone graft copolymer, and lipid vesicles, made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-distearoyl-sn-glycero-phosphoethanolamine-N-(polyethylene glycol)-mannose, were properly combined using a two-step method, successfully obtaining Roflumilast-loaded hybrid fluorescent nanoparticles (Man-LPHFNPs@Roflumilast). These exhibit colloidal size and a negative ζ potential, 50 wt % phospholipids, and a core-shell-type morphology; they slowly release the entrapped drug in a simulated physiological fluid. The surface analysis also demonstrated their high surface PEG density, which confers mucus-penetrating properties. Man-LPHFNPs@Roflumilast show high cytocompatibility toward human bronchial epithelium cells and macrophages and are uptaken by the latter through an active mannose-mediated targeting process. To achieve an inhalable formulation, the nano-into-micro strategy was applied, encapsulating Man-LPHFNPs@Roflumilast in poly(vinyl alcohol)/leucine-based microparticles by spray-drying

Nanotechnology versus other techniques in improving drug dissolution

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Spray drying for the preparation of innovative nanocoatings and inhalable nanocarriers

Spray drying is a well-established method for the transformation of liquid formulations into dried particles. This technique is still gaining increasing interest due to its numerous advantages and wide range of applications. Furthermore, the emergence of nano spray drying in the last decade, took the capabilities of spray drying to the next level, especially in the field of nanoparticle production. This thesis comprises detailed studies on the applications of spray drying in two important fields: pulmonary drug delivery and coating of medical implants. The first objective was to employ spray drying in developing an inhalable photosensitizer loaded formulation for the bronchoscopic photodynamic therapy. Pulmonary administration of photosensitizers will help achieving both selective and completely non-invasive treatment against lung cancer. Thus, offering a promising alternative to the intravenous route and achieving better patient compliance. Curcumin was chosen as a naturally occurring photosensitizer; however, its low water solubility and poor bioavailability were the main drawbacks. Therefore, curcumin nanoparticles were prepared using the nanoprecipitation method to enhance its efficacy against tumor cells. According to dynamic light scattering measurements, curcumin nanoparticles had a homogenous size distribution and a particle size suitable for cellular uptake. The prepared nanoparticles exhibited a good hemocompatibility with minor hemolytic potential and no critical influence on coagulation time. In vitro irradiation experiments using human lung epithelial carcinoma cells (A549) revealed an effective photoresponse of curcumin nanoparticles as they were able to destroy cancer cells upon activation with a light of specific wavelength using LED irradiating device. Moreover, curcumin nanoparticles exhibited a dose-dependent photocytotoxicity and the IC50 values of curcumin were directly dependent on the radiation fluence used. Nano-in-Microparticles were produced by spray drying curcumin nanoparticles with mannitol, thereby transforming the nanoparticles into a dry powder for inhalation without experiencing drastic conditions. The aerodynamic properties of the Nano-in-Microparticles were investigated using the next generation impactor which revealed a large fine particle fraction and an appropriate mass median aerodynamic diameter for a sufficient deposition in the lungs. The Nano-in-Microparticles exhibited a good redispersibility and disintegrated into the original nanoparticles upon redispersion in aqueous medium. This can be attributed to mannitol which was used as the wall material embedding the nanoparticles to keep them intact during the drying process and facilitate their release from the microparticles. Langmuir monolayer experiments confirmed the compatibility of the Nano-in-Microparticles with the pulmonary surfactant which is an important prerequisite for the safe delivery of curcumin to its site of action in the lungs (i.e. tumor cells). These results demonstrated the feasibility of spray drying for preparing inhalable drug carriers with promising potentials in the field of photodynamic therapy. In vivo studies should be the next step in order to evaluate the ability of these formulations to overcome the biological barriers of the lung. Furthermore, an accurate dosage assessment must be performed to achieve an effective therapy. The second objective was to introduce nano spray drying as a novel technique for the preparation of nanoparticles of different biomaterials that are capable of modifying the surface structure of medical implants even those with a challenging topography. The Nano Spray Dryer B-90 with its unique advanced features, facilitated particles production and implant coating in a single step omitting the need of additional drying or washing steps. This newly developed coating technique will offer several advantages: a) the ability to produce particles in the submicron range from the pure substance solution without any additives (e.g. surfactants) or time-consuming complex modifications; b) very gentle process conditions that are suitable even for sensitive and thermolabile substances (e.g. enzymes, hormones and nucleic acids); c) this technique is highly efficient and cost-effective, since a small amount of the sample is needed to achieve the best results; d) the unique cylindrical shape and functional principle of the particle collector enable a stable spatial surface coating, making upscaling easily applicable since it is possible to fix several implants on the particle collector to be coated simultaneously. In this thesis, the wide range applicability of this coating technique has been demonstrated by testing three representative model substances, namely chitosan, poly(lactic-co-glycolic acid) and curcumin. Preliminary experiments were performed on titanium plates to optimize the process parameters, thereby achieving small particle size, narrow size distribution and complete coverage of the implants. The optimized parameters were thereafter successfully applied on dental implants and the coating homogeneity was confirmed using fluorescence microscopy. Scanning electron microscope images showed that most of the produced particles were in the submicron range and had a spherical shape with a smooth surface. Particle size analysis indicated the influence of the implant position inside the particle collector on the particle size distribution where the bottom part of the collector had the particles with the narrowest size distribution. These findings paved the way for preparing biocompatible nanocoatings with antibacterial activity. The optimized process parameters from the preliminary experiments were applied on titanium discs, which were used as a model material for dental implants. The produced nanocoatings consisted of poly(lactic-co-glycolic acid) as a biodegradable polymer and norfloxacin as a model antibiotic. Scanning electron microscopy results of the nanocoatings were similar to those of preliminary experiments in terms of particle size distribution, morphology and surface structure which confirmed the reproducibility of this coating technique. The nanocoatings exhibited a typical biphasic drug release profile with a burst release in the first 48 h, followed by sustained release phase until the end of experiment. Antibacterial activity of the nanocoatings was evaluated against Escherichia coli in two stages: first, qualitatively, using agar diffusion test which facilitated the examination of large number of samples, and then quantitatively, by counting the number of viable bacterial colonies adhered to the surface of the titanium discs. The antibacterial activity of the norfloxacin loaded nanocoatings was evident and could be observed either as zone of inhibitions (agar diffusion test) or as a significant reduction in the number of viable bacterial colonies (quantification experiments). This activity was directly dependent on the norfloxacin content in the nanocoatings which was influenced by the theoretical norfloxacin loading and the titanium disc position inside the particle collector. Finally, in vitro biocompatibility of the nanocoatings was investigated using mouse fibroblasts (L929) as a standard sensitive cell line for cytotoxicity assessment. Cell proliferation on the surface of the titanium discs was studied using fluorescence microscopy followed by cell counting assay. Both methods confirmed the biocompatibility of the examined nanocoatings which exhibited similar results when compared to the uncoated titanium discs. Although nano spray drying has shown such interesting potentials for preparing novel nanocoatings, there is still room for improvement. This coating technique is still at its infancy and further optimization of the process parameters seems to be essential in order to produce nanocoatings capable of improving cell adhesion and exhibiting potent antibacterial activity even without the need of antibacterial agent

Spray drying of fenofibrate loaded nanostructured lipid carriers

AbstractThe conversion of aqueous dispersion of nanostructured lipid carriers (NLCs) into dry powder by spray drying could be a useful approach to render NLCs with better physical chemical stability than the aqueous dispersion. In this study, aqueous NLC dispersion containing fenofibrate was converted into dry, easily reconstitutable powder using spray drying. A central composite face centered design (CCFD) was used to investigate the influence of the ratio of lipid to protectant (mannitol and trehalose) and crystallinity of spray-dried powder on the particle size, yield and residual moisture content of the dried powder. A linear relationship (R2 = 0.9915) was established between the crystalline content of the spray-dried powders against the ratio of mannitol to trehalose from 3:7 to 10:0 (w/w). Spray drying of NLC aqueous dispersion using a mannitol and trehalose mixture resulted in an increase in particle size of the NLCs after reconstitution in water as compared to that in the initial aqueous dispersion. The decrease in crystallinity of the dry powder by reducing the ratio of mannitol to trehalose could improve the reconstitution of the NLCs in water. However the yield and residual moisture content of dry powder decreased with an increase in the ratio of mannitol to trehalose. Lipid nanoparticles were able to retain the drug incorporation and the prolonged drug release profile after spray drying. The experimental model was robust, and suggested that spray drying is a viable technique for the conversion of NLCs into dry powder

Spray Drying: An Overview

Spray drying is a well-known method of particle production which comprises the transformation of a fluid material into dried particles, taking advantage of a gaseous hot drying medium, with clear advantages for the fabrication of medical devices. In fact, it is quite common the production of microspheres and microcapsules designed for drug delivery systems. This review describes the different stages of the mechanism of the spray-drying process: atomization, droplet-to-particle conversion and particle collection. In particular, this work addresses the diversity of available atomizers, the drying kinetics and the importance of the configuration of the drying chamber, and the efficiency of the collection devices. The final properties of the dried products are influenced by a variety of factors, namely the spray dryer design, the feed characteristics and the processing parameters. The impact of those variables in optimizing both the spray-drying process and the synthesis of dried particles with desirable characteristics is discussed. The scalability of this manufacturing process in obtaining dried particles in submicron-to-micron scale favors a variety of applications within the food, chemical, polymeric, pharmaceutical, biotechnology and medical industries

Recent Advances Using Supercritical Fluid Techniques for Pulmonary Administration of Macromolecules via Dry Powder Formulations

Growing demands on a suitable formulation method that ensures the stability of the active compound coupled with the limitations of current methods (milling, lyophilization, spray drying, and freeze spray drying) has brought wide attention to supercritical fluid (SCF) technology. Advantages of using the SCF technology comprise its high abilities, adaptability in providing alternative processing methods, high compressibility and diffusivity of the supercritical fluid, capability as an alternative for conventional organic solvents, and the option to attain different processing parameters which would be otherwise difficult to conduct with traditional methods. This review proposes to present an up-to-date outlook on dry powder pulmonary formulations of macromolecules using SCF technology

EXPLORING EFFICACY OF AN ANTI-MALARIAL NANOMEDICINE IN NON-SMALL CELL LUNG CANCER TREATMENT

New drug and dosage form development faces significant challenges, especially in oncology, due to longer development cycle and associated scale-up complexities. Repurposing of existing drugs with potential anti-cancer activity into new therapeutic regimens provides a feasible alternative. In this project, amodiaquine (AQ), an anti-malarial drug, has been explored for its anti-cancer efficacy through formulating inhalable nanoparticulate systems using high-pressure homogenization (HPH) with scale-up feasibility and high reproducibility. A 32 multifactorial design was employed to better understand critical processes and formulation parameters so as to ensure product quality with improved anticancer efficacy in non-small cell lung cancer (NSCLC). Optimized AQ loaded nanoparticles (AQ NP) were evaluated for physicochemical properties, stability profile, in-vitro aerosol deposition behavior, cytotoxic potential against NSCLC cells in-vitro and in 3D simulated tumor spheroid model while the results confirming the significance of nanoparticle encapsulation for an enhanced anti-cancer efficacy. Furthermore, targeting potential of transferrin ligand conjugated AQ-loaded nanoparticles (Tf-AMQ NPs) was investigated, also evaluated for their physicochemical properties. Tf-AMQ NP (liquid state) exhibited an aerodynamic diameter of 4.4±0.1 µm and fine particle fraction of 83.2±3.0%, indicating drug deposition in the respirable airways. Cytotoxicity studies in NSCLC cell line with overexpressed transferrin receptors revealed significant reduction in IC50 values with Tf-decorated AQ-loaded nanoparticles compared to plain drug or non-targeted NPs, along with significant apoptosis induction (caspase assay) and reduced % colony growth in A549 and H1299 cells with Tf-AMQ NP. Moreover, 3D simulated spheroid studies (~ 7-fold reduction in spheroid volume compared to AMQ NPs) revealed efficacy of conjugated nanoparticles in penetration to tumor core, and growth inhibition. AQ’s autophagy inhibition ability significantly increased with nanoparticle encapsulation and transferrin conjugation. Further, another ligand folic acid has been explored for its ability to be conjugated to nanoparticles and to enhance anti-cancer efficacy and were found to exhibit superior anti-cancer efficacy in multiple cancer types such as breast cancer and cervical cancer. To conclude, amodiaquine can be a promising candidate for repurposing to treat NSCLC while delivering inhalable transferrin conjugated nanoparticles developed using a scalable HPH process to the target site, thus reducing the dose, side effects