Quality is the most important and necessary attribute for pharmaceutical product development, and it has become the focus of regulatory bodies in order to approve safe, efficacious, stable, patient-compliance, and cost-effective drug delivery systems. QbD-based formulation development is discovered to be an immerging technique in this context. FbD is a formulation development concept that aims to create more effective, safe, robust, cost-effective, and patient-compliant drug delivery systems. This chapter will provide an overview of Formulation by Design (FbD), different terminologies, design of experiment (DoE) and quality by design (QbD), types of experimental design, QbD applications, and FbD methodology along with benefits.

Natural exudates like Gum Odina, a complex polysaccharide, released by plants upon injury, is in high demand for applications such as food additives, emulsifiers, and binders owing to its safety, non-toxicity, and commercial viability, particularly within the pharmaceutical industry. This gum, composed of D-galactose, L-arabinose, aldobiouronic acid, and D-galacturonic acid, exhibits medicinal properties and has been explored for drug administration methods. Rheological studies revealed that Gum Odina dispersions possessed pseudoplastic characteristics, with viscosity increasing with concentration but decreasing with elevated temperature and salinity. Comprehensive analyses, including FTIR, XRD, AFM, TGA, DSC, Raman, CD spectroscopy, and NMR, were conducted to understand its properties. Furthermore, Gum Odina has demonstrated in vitro antioxidant activities against hydroxyl and superoxide radicals, indicating a significant antioxidant capacity. The inherent modifiability of Gum Odina, through chemical or biochemical means such as cross-linking, grafting, fabrication of spongy scaffolds, and coacervates, alters the gum's polysaccharide structure to enhance specific performance characteristics such as solubility, viscosity, swelling capacity, and gelation behavior, enabling customization for commercial and therapeutic applications. This review article explores Gum Odina's novel modification strategies, comprehensive physicochemical characterization, and diverse multifunctional applications, particularly in pharmaceutical preparations. The review highlights Gum Odina's tailored properties and compares its structural, functional, and rheological attributes to conventional plant gums like acacia gum. This review also addresses the economic importance, safety, biodegradability, and biocompatibility of Gum Odina, positioning it as a suitable natural, eco-friendly excipient. Its unique arabinogalactan polymer structure offers advantages over traditional gums in biopolymer application.