INTERNATIONAL JOURNAL OF ADVANCE RESEARCH
IN MULTIDISCIPLINARY

The development of non-implantable drug delivery systems (NIDDS) is critical for enhancing therapeutic efficacy, improving patient compliance, and minimizing systemic side effects. A pivotal aspect of NIDDS design is the precise control over drug release kinetics, which is overwhelmingly governed by the properties of the device's coating formulation. This theoretical paper aims to elucidate the multifaceted impact of various coating formulations on the drug release profiles from NIDDS. We will delve into fundamental mechanisms underlying controlled release, including diffusion, dissolution, erosion, and osmotic pressure, and examine how specific characteristics of coating materials – such as polymer type, molecular weight, crystallinity, hydrophilicity/hydrophobicity, and thickness – modulate these processes. Furthermore, the paper will explore the theoretical models (e.g., Higuchi, Korsmeyer-Peppas, first-order, zero-order) used to describe and predict release kinetics, and how these models are influenced by coating design. We will also discuss the role of excipients within the coating, such as plasticizers, pore formers, and stabilizers, in fine-tuning release characteristics. By integrating insights from material science, pharmaceutical engineering, and transport phenomena, this study provides a comprehensive theoretical framework for the rational design and optimization of coated NIDDS to achieve desired therapeutic outcomes.