We investigated the preparation of a new spray containing the humectant sodium hyaluronate (HA) to alleviate dry mouth symptoms.First,twelve healthy adult subjects graded the oral retention of 4 sodium alginate (ALG) solutions with different concentrations (0.4%,0.6%,0.8% and 1.0%).They also evaluated their taste,smell,degree of irritation and texture.Next,7 healthy subjects compared the bitterness of the 1.0% ALG solution to which 0.3% or 0.6% BMI-40 had been added as a bitterness masking agent.A flavoring agent,0.08% lemon essence or 0.054% menthol,was then added to the 0.3% BMI40 and 1.0% ALG mixture and 8 healthy subjects graded the taste,smell,degree of irritation and texture of these solutions.As a result,0.08% lemon essence was selected as the flavoring agent.Finally,we compared the viscosity of our spray with commercially available spray products to determine the optimal viscosity for clinical use.
The 1.0% ALG solution was ranked top for oral retention (p<0.0citation=1)and solutions became more bitter as the concentration of ALG increased.Bitterness tended to be masked by 0.3% BMI-40.The addition of HA at 0.1%,produced no remarkable difference in the scores for taste,smell,irritation and texture.The commercially available sprays had very high (52.9×104cP) or low (1.43~3.30 cP) viscosities and that of our new spray was medium in degree (519.5 cP).
The results of our study suggest that the new spray we prepared is appropriate as regards taste,texture and viscosity and we now plan to evaluate its clinical use.
