Pharmaceutical compositions and delivery systems for restoring salivary gland function and preventing oral diseases

Background

Xerostomia, commonly known as dry mouth, and periodontal disease are prevalent oral health conditions that significantly impact quality of life and overall health. Xerostomia arises from reduced saliva production or altered saliva composition, often due to medications, autoimmune disorders like Sjogren’s syndrome, radiation therapy, or systemic diseases such as diabetes mellitus. Saliva is crucial for maintaining oral hygiene, aiding digestion, and protecting mucosal tissues; its deficiency leads to discomfort, difficulties in speaking and eating, increased risk of dental caries, oral infections, and can exacerbate systemic diseases like cardiovascular disorders and diabetes itself. The burden of xerostomia and periodontal disease is particularly high among diabetic and elderly populations, and is further compounded in minority groups. Despite the widespread impact, current management strategies are largely palliative, focusing on symptom relief rather than addressing underlying biological dysfunctions, and there is a pressing need for more effective, accessible therapies that target the root causes of salivary gland hypofunction.

Current approaches to treating xerostomia and periodontal disease primarily involve saliva substitutes, stimulants like pilocarpine, and meticulous oral hygiene, but these interventions have significant limitations. Saliva substitutes offer only temporary relief and do not restore natural gland function, while pharmacological stimulants can have systemic side effects and are ineffective in cases where glandular tissue is severely compromised. Furthermore, these treatments do not address the molecular or cellular dysfunctions underlying salivary gland impairment, such as the impaired nitric oxide signaling observed in diabetes and other systemic diseases. As a result, patients often experience persistent symptoms and remain at elevated risk for oral infections, dental decay, and further complications. The lack of targeted therapies that can restore or enhance the physiological mechanisms of saliva production underscores the need for innovative solutions that can effectively treat or prevent xerostomia and its associated oral health consequences.

Technology

This technology offers a novel therapeutic approach for treating and preventing xerostomia (dry mouth) and periodontal disease by targeting the nitric oxide synthase (NOS) pathway through the administration of tetrahydrobiopterin (BH4) or its prodrugs, such as sepiapterin. BH4 is a crucial cofactor for NOS enzymes—specifically neuronal (nNOS) and endothelial (eNOS) isoforms—which are responsible for producing nitric oxide (NO), a neurotransmitter essential for healthy salivary gland function and adequate saliva secretion. The solution is delivered via a range of pharmaceutical compositions, including dentifrices (toothpastes, gels, mouthwashes), chewing gums, oral sprays, lozenges, and even parenteral formulations, with a preference for local administration to the oral cavity or salivary glands. By restoring BH4 levels, the technology enhances NOS dimerization and NO production, directly addressing the impaired salivary gland function seen in conditions like diabetes, autoimmune disorders, and as a side effect of certain medications or therapies.

What differentiates this technology is its mechanistic focus on the restoration of NO bioavailability by directly modulating the NOS pathway at the molecular level, rather than merely alleviating symptoms or providing generic saliva substitutes. The use of BH4 or its prodrugs is supported by robust experimental evidence, including diabetic animal models that closely mimic human xerostomia, where supplementation restored NOS function, NO synthesis, and saliva secretion. The versatility in formulation allows for tailored, localized delivery, maximizing therapeutic efficacy while minimizing systemic side effects. Additionally, the technology incorporates advanced drug screening methods and validated animal models, enabling the identification and optimization of effective compounds for oral health. This targeted, biochemically informed approach addresses a significant unmet need for effective, accessible treatments for xerostomia and periodontal disease, particularly in high-risk populations such as those with diabetes.

Benefits

• Restores nitric oxide synthase (NOS) activity and nitric oxide (NO) production in salivary glands, improving saliva secretion.
• Effectively treats and prevents xerostomia (dry mouth) and periodontal disease, especially in diabetic and high-risk patients.
• Utilizes local oral delivery (dentifrices, mouthwashes, gels, gums) to maximize efficacy and minimize systemic side effects.
• Addresses impaired BH4 biosynthesis and NOS dysfunction underlying salivary gland hypofunction.
• Provides versatile pharmaceutical formulations suitable for various administration routes and patient needs.
• Validated by an animal model of diabetes-induced xerostomia for screening and optimizing therapeutic compounds.
• Potentially improves overall oral health and reduces complications linked to dry mouth and periodontal disease.

Applications

• Treatment for diabetic dry mouth
• Therapeutic toothpaste for xerostomia
• Preventive gum for periodontal disease
• Drug screening for oral therapies

Additional info

This therapeutic approach addresses xerostomia and periodontal disease by modulating the nitric oxide synthase (NOS) pathway. It involves administering tetrahydrobiopterin (BH4) or its prodrugs to restore NOS dimerization and nitric oxide (NO) production. BH4, a critical NOS cofactor, enhances salivary gland function and saliva secretion, counteracting impairments seen in conditions like diabetes. Formulations include oral compositions for local delivery.