# Design and Characterization of Non-Erosive Polymeric
## 1 Introduction  
Hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) is widely used as an antiseptic, hydrolysis, and bleaching agent in various industries, including the pharmaceutical and household [1; 2; 3]. The whitening mechanism of H\({}_{2}\)O\({}_{2}\) typically involves the decomposition of H\({}_{2}\)O\({}_{2}\) into hydroxyl radicals and the oxidation of stained organic matters by hydroxyl radicals [2; 4]. Teeth whitening products with the aforementioned mechanism are applied to the stained substances in the oral cavity to perform teeth bleaching [2]. Generally, various peroxide types, including the aqueous solution of 30-50% H\({}_{2}\)O\({}_{2}\)[2; 3] and carbamide peroxide [5], are applied in tooth whitening. However, a concentration of 30-50% H\({}_{2}\)O\({}_{2}\) solution is extremely irritating for direct application as a tooth-bleaching agent. Hence, it is diluted up to 0.25-15% and mixed with various additives, such as orally acceptable polymers, surfactants, and stabilizers, to produce tooth-whitening compositions [6; 7].  
Considerable research has been conducted on tooth-whitening compositions. [PERSON] et al. investigated the whitening effects of four types of whitening protocols: tooth-paste, whitestrips, bleaching agents, and polishing application [7]. [PERSON] et al. studied the effects of 6% H\({}_{2}\)O\({}_{2}\) whitening composition with a LED light on the enamel surface and compared it with that of the orange juice [8]. [PERSON] et al. evaluated the influences of three concentrations of carbamide peroxide, which are used for tooth bleaching [9]. Among numerous studies on teeth whitening, gel-type whitening compositions containing H\({}_{2}\)O\({}_{2}\) are extensively studied. [PERSON] et al. evaluated the whitening effectiveness according to H\({}_{2}\)O\({}_{2}\) concentrations [10]. [PERSON] et al. investigated the effectiveness of bleaching gels in offices at different pH values [11]. Consequently, gel-type tooth-whitening compositions are easy to use at home or in-office and suitable for examining various effectiveness.  
Oral care products, such as tooth-whitening composition, are manufactured by combining various raw materials, such as orally acceptable polymers, solvents, fragrances, andstabilizers. Orally acceptable polymers with H\({}_{2}\)O\({}_{2}\) are available in several grades, such as polyvinyl pyrrolidone (PVP) [12], cellulose derivatives [13,14], and (meth)acrylates copolymers [14]. Among these, polyvinyl acetate (PVAc) is commonly used as a bio-adhesive and film-forming agent in various industries, including food and pharmaceutical and has been reported to be safe as a cosmetic component [11,14,15]. Ethyl cellulose (EC) is also a water-insoluble material that can be applied to the oral cavity such as coating agent [14]. Additionally, PVP exhibits excellent solubility in many solvents such as water and alcohol and provides H\({}_{2}\)O\({}_{2}\) stability through hydrogen bonding between the carboxyl group of PVP and H\({}_{2}\)O\({}_{2}\)[16]. Primeval PVAc and EC demonstrate alcohol-soluble and non-errosive properties in water phase. Therefore, they can be utilized in oral care products with appropriate contents of water and additives. Moreover, PVAc maintains good water resistance and can sustainably release active substances, such as H\({}_{2}\)O\({}_{2}\) in the oral environment [17,18].  
In this study, tooth-whitening compositions were designed using PVAc, EC, and PVP as polymeric matrices for delivery of active substances, such as H\({}_{2}\)O\({}_{2}\), for tooth whitening. In addition, their characterization and whitening efficacy were investigated.