Efficacy and Safety of High-Concentration 35 kDa Hyaluronan Gel for Chronic Nasopharyngitis

This prospective, single-center, single-arm, open-label pilot clinical study is designed to investigate the efficacy and safety of a 13.6% high-concentration 35 kDa hyaluronan (HA35) nasopharyngeal care gel for the management of chronic rhinitis and chronic pharyngitis.

Participants meeting all eligibility criteria will receive the HA35 gel via nasopharyngeal administration, one unit per nostril, twice daily (morning and evening) for 10 consecutive days.

Symptom assessments will be performed at baseline, 30 minutes after the first administration, 1, 2, and 3 hours after the first morning dose, and on day 10. Assessments include numeric rating scales (NRS) for nasopharyngeal discomfort, posterior pharyngeal discomfort and cough, nasal airflow obstruction, overall rhinitis and pharyngitis symptom severity, and subjective mental clarity.

Safety evaluations will monitor all adverse events, local tolerability, and any unexpected reactions throughout the study period.

This study involves a non-invasive, non-pharmacological non-drug intervention with minimal risk to participants. All procedures will be conducted in accordance with the Declaration of Helsinki, and written informed consent will be obtained from all subjects prior to enrollment.

• 13.6% High-Concentration 35 kDa Hyaluronan (HA35) Nasopharyngeal Care Gel (Device), also known as HA35 Nasopharyngeal Gel; HA35 Care Gel: A topical, non-pharmacological nasopharyngeal care gel containing 13.6% high-concentration 35 kDa hyaluronan. It is designed to support mucosal hydration and reduce inflammation in the nasopharynx. Administration is via direct nasopharyngeal application, twice daily for 10 consecutive days.

Primary outcomes

• Change in Posterior Pharyngeal Discomfort and Cough NRS Score (0-10) [Baseline to 30 minutes after first administration]: Change in posterior pharyngeal discomfort and associated cough intensity, measured using a 0-10 Numeric Rating Scale (NRS), where 0 = no discomfort/cough and 10 = worst imaginable discomfort/cough.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Age 18-80 years, male or female
* Clinically diagnosed with chronic rhinitis and chronic pharyngitis for ≥3 months
* Baseline nasopharyngeal discomfort NRS score ≥4 points
* Baseline posterior pharyngeal discomfort NRS score ≥4 points
* Voluntary participation and signed written informed consent
* Ability to complete symptom assessment independently

Exclusion Criteria:

* Acute upper respiratory tract infection within 2 weeks
* Use of antihistamines, intranasal corticosteroids, decongestants, or other nasal medications within 2 weeks prior to screening
* History of nasal/sinus surgery within 6 months
* Known hypersensitivity to hyaluronan or any gel ingredients
* Pregnant or lactating women
* Severe systemic diseases or malignant tumors