Non-Traditional Natural Stabilizers in Drug Nanosuspensions

Poor solubility of many drugs, with ensuing low bioavailability, is a big challenge in pharmaceutical development. Nanosuspensions have emerged as a platform approach for long-acting injectables and solid dosages that enhance drug bioavailability. Despite improvements in nanosuspension preparation methods, ensuring nanosuspension stability remains a critical issue. Conventionally, synthetic and semi-synthetic polymers and surfactants are used in nanosuspension formulations. However, no polymer or surfactant group is universally applicable to all drugs. This fact, as well as their toxicity and side effects, especially if used in excess, have sparked the interest of researchers in the search for novel, natural stabilizers. The objective of this paper is to provide a comprehensive analysis of non-traditional natural stabilizers reported in the literature published over the last decade. First, physical stability and stabilization mechanisms are briefly reviewed. Then, various classes of non-traditional natural stabilizers are introduced, with particular emphasis on their stabilization potential, safety, and pharmaceutical acceptability. Wherever data were available, their performance was compared with the traditional stabilizers. Furthermore, the benefits and limitations of using these stabilizers are examined, concluding with future prospects. This review is expected to serve as a valuable guide for researchers and formulators, offering insights into non-traditional natural stabilizers in drug nanosuspension formulations.