Novel Drug Delivery Systems (Part 1)

Modern pharmaceutical research and development has evolved to rely heavily on controlled drug delivery systems because they provide creative ways to improve therapeutic results while reducing side effects. The underlying ideas and justification for controlled drug delivery systems are covered in detail in this chapter. Beginning with a discussion of the drawbacks of conventional drug delivery techniques and the benefits of controlled release, the chapter explains the need for controlled drug delivery systems in modern medicine. The requirements for the design and formulation of controlled drug delivery systems have also been discussed in the chapter. The concepts of controlled drug release, which cover a variety of mechanisms, including diffusion, erosion, and osmosis, take up a sizeable section of the chapter. Additionally, emphasis is put on the function that mathematical modeling plays in predicting and optimizing drug release characteristics. It examines the wide spectrum of therapeutic uses for controlled drug administration, such as the treatment of chronic pain, cancer, diabetes, and other chronic disorders. The chapter also illuminates the future trends of such drug delivery systems like nanotechnology, personalized medicines, and advancements in medical devices. It also explores regulatory aspects and challenges involved in the design and commercialization of these systems, placing emphasis on the necessity of stringent quality control and safety evaluations. In conclusion, this chapter is a useful resource for researchers, scientists, and medical experts who want to understand underlying ideas and justifications of controlled drug delivery systems.

The pharmaceutical industry has shown significant interest in controlledrelease dosage forms due to their ability to improve pharmacological therapy by providing prolonged and regulated drug administration. The pharmacokinetic properties of a medicine are essential in establishing its efficacy and safety in a therapeutic setting. Controlled-release dosage forms offer significant advantages, such as reduced dosing frequency, improved patient compliance, and fewer adverse effects. To maximize the use of these benefits, it is critical to understand the complex interplay between formulation design, pharmacological properties, and controlled release systems pharmacokinetics. This chapter examines the pharmacokinetic aspects of controlled-release formulations, providing insight into their drug-release methods, absorption, distribution, metabolism, and excretion. The chapter also delves into the various elements that influence the rate of drug release from controlled-release dosage forms. These aspects include mechanisms such as diffusion, dissolution, and erosion. This study also investigates the impact of these mechanisms on medication absorption in the gastrointestinal tract and their influence on the drug's pharmacokinetic characteristics. Furthermore, the chapter emphasizes the importance of employing modeling and simulation approaches to predict the behavior of pharmaceuticals released from controlled-release formulations. Furthermore, the chapter undertakes an endeavor to examine the impact of pharmacokinetic parameters on the dosing schedule, therapeutic monitoring, and methods to enhance bioavailability. The chapter also discusses the importance of tailored drug delivery methods for specific patients, as well as the potential of personalized medicine. Understanding the pharmacokinetic parameters of controlled-release formulations is critical for optimizing pharmaceutical treatment. Gained knowledge can guide the development of innovative drug delivery methods, enhance patient outcomes, and accelerate pharmaceutical sector advancements

The concept of a drug-delivery system (DDS) is not entirely new. Recent years have undoubtedly seen notable advancements in the identification and management of several illnesses. Medication administration to affected areas is an important part of DDS. A sufficient number of drug carriers are required to deliver an adequate amount of drug to the lesion. Polymers that expand and condense in reaction to pH levels outside of the body are being studied by researchers. The investigation is being carried out at a breakneck pace all over the world. Not only are advances in traditional technologies being made but innovations are also being developed and tested. The purpose of this chapter is to discuss a few of the polymer compounds that are utilized in controlled medication delivery systems. Both newcomers and scientists working in this fascinating field of applied polymer research will find the paper to be a valuable resource.

Controlled drug delivery systems, which release drug/s in a predetermined manner, offer numerous advantages over conventional drug delivery systems. These advantages include improved bioavailability, reduced dose frequency, minimized fluctuations in plasma drug concentration, and sustained drug release. The major drawback of the unit dosage form is dose dumping, which can be effectively overcome by multiple unit dosage forms like microcapsules. The microencapsulation technique involves enclosing drug/s by a thin coating shell, and the resultant product is referred to as microcapsules. This technique has potential applications, especially in delivering enclosed drug/s in a controlled manner, protecting them from harsh environments, masking unpleasant tastes, and many more. Several techniques, such as mechanical processes, chemical processes, and physicochemical processes, are used to encapsulate drug/s. Drug release from microcapsules is predominantly facilitated by diffusion, whereas swelling and dissolution, erosion and degradation, and osmosis are minor mechanisms. The polymers, which can be natural or synthetic, play a stellar role in the controlled release of drug/s from microcapsules. Prepared microcapsules are characterized and evaluated by various techniques for shape, size, surface characteristics, drug release and release kinetics, rheological behavior, etc. Despite the significant promise, various constraints and restrictions hinder the use of microencapsulation technology, creating a gap between real-life clinical practice and its therapeutic applications. The current chapter provides a comprehensive analysis of the most recent techniques, characterization and evaluation techniques, challenges, and commercially available microencapsulated pharmaceutical products.

Mucoadhesive drug delivery systems have gained significant attention in the field of pharmaceutical research due to their ability to enhance drug bioavailability, prolong residence time, and improve therapeutic outcomes. This chapter provides a comprehensive overview of mucoadhesive drug delivery systems, highlighting their importance in overcoming various challenges associated with conventional drug delivery. The chapter commences by elucidating the physiological and biochemical aspects of mucosal surfaces, emphasizing the significance of mucoadhesion in optimizing drug absorption and distribution. It explores the diverse applications of mucoadhesive systems across different mucosal sites, including the buccal, nasal, ocular, vaginal, and gastrointestinal mucosa. Additionally, the mechanisms underlying mucoadhesion, such as hydrogen bonding, electrostatic interactions, and covalent bonding, are thoroughly examined. The chapter delves into the various classes of mucoadhesive polymers, such as natural, synthetic, and semi-synthetic polymers, highlighting their distinct properties, applications, and evaluations. The chapter addresses key considerations such as biocompatibility, safety, and regulatory aspects associated with the development of mucoadhesive formulations. In conclusion, this chapter serves as a valuable resource for researchers, scientists, and practitioners in the field of drug delivery, offering a comprehensive understanding of mucoadhesive drug delivery systems and their potential to revolutionize the delivery of therapeutic agents across mucosal membranes. 

Administration through the oral route is the most accessible and preferred due to its many advantages. Most of the drugs administered orally show poor bioavailability due to less residing time at the gastric absorption site. To boost the bioavailability of such drugs, it is important to extend the residing time of the drug in the upper GIT, which can be achieved by using gastroretentive drug delivery systems (GRDDS). There are multiple conventional and advanced gastroretentive systems based on various mechanisms, namely high-density systems, floating systems, magnetic systems, mucoadhesive systems, expandable systems, raft-forming systems, and many more. Novel techniques like 3D printing technology are also an emerging approach in the fabrication of GRDDS. Various in vitro and in vivo techniques are used for the analysis of GRDDS, like buoyancy time, gastroscopy, scintigraphy, ultrasonography, etc. This chapter is the comprehensive literature exploring GRDDS, including various principles in the fabrication of GRDDS, techniques of preparation of GRDDS, polymers used in the fabrication of GRDDS, evaluation of GRDDS, application of 3D printing in GRDDS, and patent scenario.