Pullulan based polymeric novel drug delivery systems: A review on current state of art and prospects

Pullulan is an exo-polysaccharide produced by the Aureobasidium pullulans and explored for several therapeutic benefits. Pullulan-based polymeric drug delivery system can be a pioneering strategy in the treatment of various respiratory ailments as it provides multifactorial merits such as sustained-release pattern, biocompatibility, non-immunogenic nature, chemical transformability, well permeation through the lung mucosa as compared to the other polysaccharides etc. Pullulan, having the chemical formula (C6H12O5)n, and its wide spectrum of derivatives are a tasteless, odor less, non-mutagenic, water-soluble and non-toxic edible polymers implemented for several delivery methods in biological applications to create stimuli-responses in reaction to the environmental changes including pH, charge, light, and temperature, making it more acceptable for efficient delivery as per the pathophysiological state. The utilization of drug cargoes has also been beneficial for cancer treatment, vaccine delivery, protein delivery, and tissue engineering. In this review paper, various aspects relevant to the development of pullulan-based micro and nano drug carriers as the potential polymeric carriers for the delivery of the active ingredient moieties to treat pulmonary ailments, cancer and other disorders are discussed with an emphasis on their therapeutic potential for further explorations. Pullulan is a versatile molecule that can undergo chemical modifications to enhance its potential for forming hydrogen bonds, interacting with hydrophobic substances, or engaging in electrostatic interactions with various small molecules. It has been utilized in biomedical applications, such as targeting cancer cells and liver cell receptors. Since many therapeutic compounds have low solubility and are hydrophobic in water, it is crucial to strike a balance between their hydrophilic and hydrophobic properties when designing drug delivery systems to maximize the therapeutic effects of medications. Various carriers viz., conjugates, hydrogels, dendrimers, micelles, films, nanogels, microspheres, liposomes, niosomes, microparticles, and nanoparticles, offer distinct advantages for loading and delivering drugs. The most recent approach involves simulating interactions among the drug, the polymeric carrier, and other components of pharmaceutical formulations, including additives, surfactants, and flavour modifiers.