Inclusion Criteria:  ACR clinical criteria of knee OA Radiographic knee OA (Kellgren-Lawrence grade >1) Age ≥ 50 years VAS pain >= 40/100 mm at baseline Non-use of NSAIDs one week before the baseline Symptoms present on most days for at least 3 months  Exclusion Criteria:  Any form of inflammatory arthritis Use of another topical product at the application site Treatment with intraarticular hyaluronic acid within 6 months Treatment with intraarticular glucocorticoid within 2 months Knee injury/surgery or diagnostic arthroscopy within 3 months Allergic reaction to diphenhydramine or any component of the formulation Participant has clinical signs and symptoms suggestive of COVID-19, eg, fever, dry cough, dyspnea, sore throat, fatigue or confirmed infection by appropriate laboratory test within the last 4 weeks prior to Screening