Formulation and Evaluation of Medicated Chewing Gum Containing Eggshell-Derived Calcium Carbonate

Dentin hypersensitivity and enamel demineralization rank among the most frequently encountered oral health disorders in clinical practice, collectively affecting hundreds of millions of individuals across all age groups. Despite their high prevalence, the management of these conditions remains largely dependent on conventional formulations — including desensitizing toothpastes, fluoride mouthwashes, and topical gels — that are constrained by short oral residence time and inconsistent patient compliance. These limitations reduce the therapeutic efficiency of active ingredients, as meaningful contact with tooth surfaces is difficult to sustain over clinically relevant periods using standard dosage forms. There is therefore a compelling need for an alternative delivery platform that can maintain prolonged local drug concentrations within the oral cavity while simultaneously improving palatability and ease of use. The primary objective of this study was to formulate and evaluate a medicated chewing gum incorporating eggshell-derived calcium carbonate as a natural remineralizing agent, potassium nitrate as an established desensitizing agent, and xylitol as an anti-cariogenic excipient with salivary-stimulating properties. The formulation aimed to exploit the sustained-release characteristics of the chewing gum matrix to deliver these active components continuously into saliva during mastication, thereby maximizing their therapeutic interaction with enamel and dentinal surfaces. Eggshell-derived calcium carbonate was prepared from cleaned and processed hen eggshells through a standardised protocol involving washing, membrane removal, drying, pulverisation, calcination at 800°C, and sieving to a particle size below 50 μm. Nine formulation batches (F1–F9) were prepared using a fusion method by varying the concentrations of calcium carbonate (8–12%), potassium nitrate (3–7%), and glycerin as plasticizer (3–7%), with a gum base as the chewing matrix and xylitol and mint flavour as excipients. The prepared gums were evaluated for a comprehensive range of physicochemical and organoleptic properties including appearance, weight variation, thickness, hardness, elasticity, stickiness, surface pH, moisture content, folding endurance, drug content uniformity, and stability as per ICH guidelines.