**1. Introduction**

Biotechnological developments in the field of biomedical science have become more widely publicised in recent years, as the relevance of life extension and quality of life has become more widely recognised. Drug delivery system research, in particular, has been identified as one of the most challenging problems in biomedical science. In general, drug delivery system research focuses on keeping drug concentrations in the blood at a minimum and avoiding drug toxicity in vivo [1]. Thin films, in general, are ideal for targeting sensitive regions that tablets or liquid formulations may not be able to reach. Thin films have been shown to increase pharmaceutical action onset, dose frequency reduction, and treatment efficacy. Consequently, thin films may be beneficial in reducing excessive proteolytic enzyme metabolism and eliminating pharmaceutical side effects [2].

Thin films have demonstrated their ability to improve medication action onset, reduce dose frequency, and improve treatment efficacy. Thin films may also be useful for decreasing excessive metabolism induced by proteolytic enzymes and removing the negative effects of medicine [3].

Penetration enhancers are substances that temporarily lessen the skin's impermeability, making it easier to absorb penetrant through the skin. These materials should be pharmacologically inert, non-toxic, non-irritating, non-allergenic, and compatible with the drug and excipients, odourless, tasteless, colourless, and inexpensive, as well as having good solvent properties. The enhancer must not provoke a loss of physiological fluids, ions, or other endogenous elements, and the skin should quickly regain its barrier properties after it has been removed [4]. Chemical penetration enhancers boost skin permeability by reversibly eroding or changing the physicochemical makeup of the stratum corneum to reduce diffusional resistance. Most chemical penetration enhancers irritate the skin, which is one of their drawbacks [5]. It's unsurprising that agents that interrupt ordered lipid patterns, cellular membranes, and components also disrupt ordered lipid structures, cell membranes, and constituents. The clinical utility of numerous chemical permeation enhancers has been limited due to the toxicity related to them. In recent years, the FDA has looked into essential oils, terpenes, and polymeric enhancers, all of which are GRAS (Generally Recognised as Safe) [6].

Polysaccharides, proteins, peptides, polyesters, and other substances are examples of natural polymers. Because of their biocompatibility and processability, the first two kinds of endogenous polymers were widely explored in the DDS. Because polysaccharides and proteins are more similar to the extracellular matrix, natural polymer-based medicament carriers are less intrusive. Furthermore, the polymers' backbones are plentiful in a variety of easy-to-change groups, such as amino groups, carboxyl groups, hydroxyl groups, and so on, allowing them to be easily modified [7]. Finally, as life science research developed, more specific connections between native polymers and organs or cells were uncovered. Natural polymers have been demonstrated to have a stronger affinity for cell receptors and to regulate cellular processes including adhesion, division, and migration, implying that they could be exploited to create more targeted and efficient high-efficiency applications [8]. Furthermore, their breakdown behaviour in the presence of enzymes in vivo ensures their potential to develop stimuli-responsive delivery in local locations.

The main objective of thin films delivers drugs topically, where they are absorbed by the skin and into the bloodstream. They provide consistent delivery of small amounts of a drug into the bloodstream over a long period. The duration of wear time and the amount of drug delivered is different from film to film.
