Nanoparticles and Nanocarriers Based Pharmaceutical Formulations

This chapter outlines the introduction of nanoparticles and nanocarriers, within which it delineates their classification into various categories of polymeric nanoparticles, metal nanoparticles, magnetic nanoparticles, inorganic nanocarriers, dendrimers, vesicular carriers, micelles, and a lot more, their synthesis techniques such as physical, chemical and biological, and their application in the medical sector. The chapter also focuses on various challenges faced by these nanocarrier systems in nanomedicine as well as their advantages over conventional drug delivery. Overall, this chapter is a comprehensive compilation of available information on recent advances in the field of nanomedicine through an elucidation of nanoparticles and nanocarrier systems. During the last decade, surplus new nano-based strategies for improved drug delivery and nanocarriers centered therapeutic approaches have been adopted for oral drug delivery, pulmonary drug delivery, cutaneous drug delivery, drug delivery into the brain, for cardiovascular diseases, intracellular targeting, gene delivery, protein delivery, insulin delivery, anticancer targeting and many more. Currently, nanoparticleintegrated diagnosis and imaging have been in abundant use seeing an urgent need for early detection and diagnosis of various lethal diseases.

Delivering drugs through various delivery systems into the body for successful treatment of diseases is most entrancing deeds for the pharmaceutical analyst. Conventional drug delivery systems have various hindrances like loss of medication and poor bioavailability of drugs. Polymer-based nanocarriers such as polymeric nanoparticles upgrade bioavailability of drug, delivery of drug to specific site and improve solubility of drugs. They are widely explored as controlled, precise, sustained and continuous release systems for drug delivery and are easily incorporated and appropriate for practically all parts of nanomedicines and bring new trust in field of drug conveyance by redesigning drug viability and diminishing drug toxicity. This chapter mainly focuses on polymers and techniques engaged with advancement of polymer-based nanoparticles and their applications in therapeutic intervention. 

In modern-day medicine, nanoparticles and nanocarriers are rapidly evolving fields in therapeutics and are the building blocks of nanomedicine, which emphasize the use of nanoscale particles that have a wide array of functions from working as a diagnostic tool to the screening, monitoring, and controlling of various diseases to the delivery of drugs at specific targets in a controlled manner. With the advancement in technologies, it is proven that nanoparticles have a greater potential in wide biomedical applications. Due to their ability to bind with both hydrophobic and lyophilic substances, lower particle size, higher carrier capacity, nanoparticles serve as a favorable platform for specific and targeted drug delivery in disease treatment. Nanoformulations can improve the safety, pharmacokinetic characteristics, and bioavailability of administered drugs, and can improve the therapeutic effect when compared with conventional therapies. Besides, nanoparticles may also be effective in delivering nucleotides, vaccines, and recombinant proteins. Several varieties of nanoparticles are available: different metal and polymeric nanoparticles like gold/silver nanoparticles and micelles, dendrimers. Carbon-derived nanoparticles like quantum dots, carbon tubes, and many other nano assemblies. Numerous nanocarriers, nanoparticle-based drug delivery systems, and drug targeting systems are either developed or under development. In this chapter, we will emphasize mainly the specific and targeted nanoparticles and the use of various nanocarriers for the targeted delivery of drugs in various diseases. The opportunities and challenges of using nanoparticles/nanocarriers in targeted delivery along with its clinical applications are also discussed here.

Drug targeting specific cells/tissues of the body without their becoming a part of the systemic circulation is a prominent area of research in drug delivery, with the main emphasis on improvement in formulation and development. Drug-targeting can improve the viability, lower/minimize the adverse/side effects, and can become cost-effective. Certain limitations like short circulating half-life, bioavailability issues, rapid metabolism and degradation, poor tissue distribution and penetration in the blood-brain barrier, intestinal absorption barriers, etc., are associated with the delivery of various therapeutic agents. Nanocarriers have arisen in the field of drug targeting with valuable delivery of drugs to site-specific/desired areas which is a significant therapeutic advantage since it keeps drugs from being conveyed to some unacceptable spots. Nanocarriers prevent the obstacles in clinical utilization of the therapeutic agents as they decrease the serious and critical side/adverse effects by targeted drug delivery and provide slow and sustained drug release. Nanocarriers bring new trust to drug targeting by upgrading the efficacy, defeating resistance, and minimizing toxicity. This chapter mainly focuses on the role and benefits of nanocarriers in drug-targeting and nanocarriers as prominent systems for targeting and delivering drugs to achieve maximum effects with improved therapeutic response. 

Nanotechnology is a multidisciplinary field of study that bridges chemistry, engineering, biology, and medicine. The utilization of the nanotechnological approach for the development of theranostic nanocarrier system is capable of being loaded as drug therapy/delivery and diagnostic vehicles/means. A very recent term, theranostic nanomedicine, has gained much attention as a favorable model for various types of progressive disease. Theranostic nanocarriers' strategy utilizes the diagnostic excellence mediated treatment of such illnesses that required individual therapy, such as in cancer. These can impart an essential role in improving public health regarding high-stress lifestyle-related challenges in diabetes, asthma, cancer, hypertension, and many infectious diseases, as the diagnosis of these circumstances and the treatment strategy, are also possible with biomedical applications of these nanomaterials. It includes benefits from both worlds: highly powerful nanocarriers to drug delivery and diagnosis spawned the concept, enabling the emergence of personalized medicine. This chapter discusses the state of various nanocarriers' art in the form of NPs and nanodevices applications in medical diagnosis and disease treatments. It presents key insights and current advancements into the intriguing biomedical applications of NPs, including bioimaging of biological surroundings and their significance as a critical early detection tool for various diseases. It also describes their types and limitations concerning conventional means. The topic has attracted significant attention and interest as diagnostic and treating nanocarriers' can target various illnesses faced by the healthcare providers suggested by several researchers over the past decade. Additionally, with recent advances in nanoscience and nanoscale materials, the creation of different diagnostic or therapeutic devices is also discussed briefly. Along with nanocarrier systems' therapeutic and diagnostic aims, physicochemical advantages even considerable potential to be studied concerning health system, which is useful for protecting active drug molecules from degradation, targeted and site-specific drug deliveries are also discussed. Despite the numerous technological, scientific, regulatory, and legal hurdles that nanomedicine faces, researchers are driven to develop new medications and nanomedicine devices. As a result, the development of nanoparticlebased drug delivery and diagnostic devices could help improve patient comfort and convenience while also lowering treatment costs.

Helicobacter pylori (H. pylori), a prevalent human-specific pathogen, plays a key role in the development of peptic ulcer disease, gastric carcinoma, and gastric mucosa associated lymphoid tissue lymphoma. Once infected, those bacteria reside below the gastric mucosa adherent to the gastric epithelium, and entry of drugs to this target site is very difficult. The bacteria can also acquire resistance to commonly used antimicrobial drugs. Thus, an effective antimicrobial concentration cannot be achieved in the gastric mucous layer or on the epithelial cell surfaces where H. pylori exist and caused inefficient treatment. Such challenges have encouraged researchers into developing some therapies based on nanotechnology. 

The oral route is an extremely accepted route for the administration of several drug delivery systems. This route exhibits several merits for the controlled and sustained release of different formulation types to attain enhanced therapeutic responses. Gastro-retentive nanocarriers (NCs) (GRNCs) have advantages due to their aptitude for extended retaining potential in the stomach environment and thereby elevate gastric retention and augmenting bioavailability of the drug molecules. This chapter covers various merits and demerits of gastro-retentive NCs. Further, it also discusses some gastro-retentive strategies and their applications in the therapy of various illnesses, for instance, swelling NCs, porous NCs, floating/non-floating NCs, lipid NCs, Polymeric NCs, bioadhesive NCs, and magnetic NCs, etc. 

Anticancer agents are known for their cytotoxic action against tumors, but the spread of their activity to noncancerous tissue is highly undesirable and may be toxic. The conventional methods of drug delivery pose numerous restrictions, involving side effects, lack of patient compliance, etc. Nanocarrier-based drug delivery alternatives offer the potential for the management of cancer, as they not only confer better delivery but also efficient targeting to the tissues with limited toxicity. Nanoparticles offer localization in tumors in the vicinity of capillaries, that accounts for improved penetration and prolonged detainment of drug in tumors. Under the tremendous potential of nanoparticles. The exploitation of multi-functional nanocarrier approaches is a burgeoning research subject, driven by increasing medical needs in the area of cancer therapy. Several nano-formulation have been approved for the treatment of cancer. This chapter is an attempt to provide an overview of the recent developments in nanoparticle formulations for cancer treatment and presents a comprehensive outlook of the clinical studies and utilization in different prevalent cancers affecting the brain, lung, breast, colon, cervix, and prostate, etc.

Nanoemulsions (NEs) are stable nanocarrier systems consisting mainly of oil and water, which are stabilized by surfactant with cosurfactant. Due to their typical size, nano-emulsions are transparent or translucent, and minute droplet size makes them stable against sedimentation or creaming. The nanoemulsion system may be in the form of oil-in-water (O/W) or water-in-oil (W/O). The recent literature revealed that NEs as a colloidal carrier system has been confirmed to be a valuable strategy to improve the bioavailability of topically applied drugs. NE has been proposed as a viable alternative to conventional topical dosage forms due to the ability to overcome the skin/ocular barriers faced after administration. Better permeation rate, improved therapeutic efficacy and reduction of dose, non–specific toxicity, and targeted drug delivery system can improve drug effectiveness when drugs are incorporated into NEs. In recent years, research studies have focused more on ion nanoemulsion systems using a mixture of surfactants to solve critical factors, such as solubility, stability, and drug delivery applications. This chapter outlines the recent development in nanoemulsion as a delivery system to study topical drug delivery.

The delivery system plays a vital role in managing the pharmacokinetics and pharmacodynamics of a drug. The size of the carrier system contributes to its pharmacological action. Lipid-based carriers refer to the formulations containing a dissolved or suspended drug in lipidic excipients. Lipoidal systems as carriers are achieving heights due to their significant lipid nature and the size of particles in the delivery system. The micro/nano-sized lipid-based carriers possess versatility in improving the physic-chemical properties of drugs. Also, they are biocompatible and can be administered through all possible routes. Lipid-based drug delivery carrier systems of new and existing formulations can be commercialized to achieve the desired range of product specifications. Solubility of the drug in various lipids is a key factor in the development of the delivery system. Lipids as functional excipients are compatible with solid, liquid, and semi-solid dosage forms. Besides improving/enhancing the solubility and bioavailability, lipids provide multiple broad-based applications in the pharmaceutical delivery system.

Liposomes are emerging as uni or multilamellar micro particulate phospholipid bilayer sphere vesicles, which can be produced synthetically and have the ability to encapsulate any kind of drug molecule. Either hydrophilic or lipophilic drug substances can be easily entrapped in these vesicles for efficient delivery of a drug. Over the past decades, these have been under investigation to develop novel and revolutionary drug delivery aspects in the pharmaceutical field. Liposomes are based on a simple mechanism of formation of the enclosed sphere formed when amphiphilic lipid comes in contact with the aqueous layer. The advancements in liposomes have paved pathways towards efficient drug delivery through alteration in the bioavailability and bio-distribution of drugs. Classified into various types, liposomes can be prepared using various techniques involving mechanical dispersion, solvent dispersion, and detergent removal methods. The development of these liposomes has profound the advanced delivery characterization. This helps deliver the molecules at the target site, and the number of liposomal products in clinical use has now increased. Recent advances are incorporating the emergence of second-generation liposomes over conventional liposomes, which will help modulate the encapsulation efficiency and drug release from liposomes. This literature briefly focusses on various aspects of liposomes, which further relates to the growing advances and interest in this field.

Niosomes, which are well recognized for their non-ionic surfactant characteristics, are considered to be innovative drug delivery methods since they improve the solubility and stability of medicinal compounds when administered orally. It has been shown that niosome vesicles are closed bilayer structures that may exist in aqueous fluids and are produced by the self-assembly of different types of hydrated non-ionic surfactants and amphiphile monomers in aqueous media. Because the monomers maintain a wide range of kinetic activity inside the assembly, they are referred to as liquid crystal structures in terms of thermodynamics. It is just the total of different processes for the dispersion of monomers and solvents that results in the formation of the final systems. Niosomes are made up mostly of lipid molecules and nonionic surfactants, which are the two most important components in the process of making them. Nonetheless, as the name suggests, component surfactants play a key role in the creation of niosomes, owing to the fact that non-ionic surfactants were often employed to organize niosomes during their formation. They are especially well-suited for drug delivery because they have the ability to encapsulate medicines that are both lipophilic and hydrophilic in nature. These materials are appealing for a number of drug delivery goals, including drug targeting, controlled release, and permeability enhancement, because of their chemical stability, cheap production costs, and composed of biodegradable and non-immunogenic components. Niosomal vesicular carriers can also help to minimize problems such as physical and chemical instability. This book chapter contains a brief knowledge about structural components and integrity concerning the advanced method of noisome preparation. The characterization techniques essential for noisome have also been discussed in detail. The recent examples for different applications are also included for therapy /diagnostic purposes based on the route of administration and disease state. 

Being the most abundant cell in the human body, resealed erythrocytes have been utilized as a promising natural biological carrier for therapeutic delivery. In various therapeutics, delivery resealed erythrocytes are found to be an alternative delivery approach with overcoming toxic and rapid clearance effects, such as enzymeloaded bioreactors performing vital reaction along with improving the enzymes circulation time, as drug-loaded carrier affords sustained release of drug and in drug, targeting delivers drugs release in specific target organs without recognition by the immune system. From the research level to clinical development, it has been observed that the drug carrier expedition faces many regulatory and industrial process development challenges. Resealed erythrocytes possess many remarkable properties such as biocompatibility, biodegradability, long circulation and flexibility to encapsulate a wide variety of therapeutic compounds via employing different chemical and physical methods. It is possible to obtain resealed RBCs by collecting them from the source of concern (e.g., humans, rats, rabbits, pigs, and so forth) through blood samples following the separation of RBCs. A number of techniques are then used for effective drug loadings, including hypotonic dialysis, hypotonic dilution, hypotonic preswelling, endocytosis, lipid fusion, electric cell fusion, and chemical disturbance. Up to date, resealed erythrocytes have been explored as a carrier for various therapeutic drug substances (antiviral, anti-inflammatory, steroids and anticancer, etc.), enzymes, antibiotics, and diagnostic agents. The main objective of this chapter is to emphasize the advantages, limitations, source, isolation, loading methodology, characterization parameters, and finally, to pay attention to in-vivo studies, clinical applications, and future potential of resealed erythrocytes.

Gene therapy aims at intercellular delivery of functional genetic material to the affected area to restore its function or block a dysfunctional gene using viral vectors (Adeno-associated virus) or non-viral vectors (liposomes, SLNs). Gene therapy for the management of ocular diseases is emerging with improved and encouraging results. The Eye has well-defined anatomy, tight ocular barriers, and immune-privileged. It is a perfect target for gene therapy. Recently, many clinical trials are underway or have been completed. The success of these clinical trials promotes the treatment of several ocular diseases (Age-related macular degeneration, glaucoma, retinitis pigmentosa, and choroideremia). Gene therapy should possess an efficient targeting capacity and longstanding gene expression. Viral vectors are mainly used for gene therapy, but due to the risk associated with immunogenicity and mutagenesis, non-viral vectors are widely utilized. This chapter summarizes the recent development of therapeutic gene delivery approaches for the effective management of ocular diseases and their use in ophthalmology.

This chapter focuses on the sustainable environment for the synthesis of nanoparticles using microorganisms, enzymes, or botanical extracts as an alternative to chemical synthesis, and their subsequent application in herbal drug delivery systems. The objective is to emphasize the rapid, straightforward, and reliable synthesis of nanoparticles using a novel, preferably eco-friendly process. Herbal drugs are gaining prominence due to their ability to treat chronic diseases, such as arthritis and hypertension. However, several constraints, such as poor solubility, poor bioavailability, and low oral absorption, have restricted their use. Nanoparticle-loaded phytochemicals disperse conveniently in liquid and thus perforate easily. Merging nanotechnology with herbal medicine is required to produce better therapeutics with improved activity in the fight against long-term chronic disorders. Tissue engineering is another significant application of nanotechnology.