Assessment of the Deleterious Effects of Therapeutic Antitussives on Enamel. Mapping the Chemical Profile of Over the Counter Cough Lozenges Using Analytical HPLC

Aim: 1) To evaluate and compare changes in the micro hardness of enamel after exposure to different cough lozenges.

2) To assess the pH of dissolved lozenge solutions, and

3) To analyze the number of components in cough lozenges using Analytical HPLC (High-performance liquid chromatography).

Study Design and Methods: Experimental Confirmatory Study.

Forty extracted human molars were selected for the study. The teeth were embedded in self-cured acrylic resin except a small rectangular area of 3.0 mm × 2.0 mm on the buccal surface. Micro hardness tests were carried out with a Vickers Diamond Indenter with a 50 gm load for 15 seconds. Based on the lozenges used, the samples were randomly divided into 4 groups (n=10);

Group 1: Control - No treatment

Group 2: Lozenge - A

Group 3: Lozenge - B

Group 4: Lozenge - C

Lozenges were dissolved in 20 ml of artificial saliva for 30 minutes. After complete dissolution, the samples were immersed in lozenges solution for 30 minutes at room temperature, four times a day for one week. After each exposure specimens were washed in deionized water for 20 seconds and immersed in artificial saliva until the next experimental step. At the end of 7 days, again the micro hardness of the enamel surfaces was measured with the Vickers Indenter at the same specifications.

Change in the pH of artificial saliva following dissolution of lozenges was assessed using Microprocessor pH meter.

Components of cough lozenges were separated and analyzed using Analytical HPLC.

Results: Paired t- test and ANOVA were used for statistical analysis. All experimental groups showed a significant decrease in micro hardness of tooth enamel. Analytical HPLC revealed the complex composition of these lozenges.

Conclusion: Increased consumption of cough lozenges reduces the micro hardness of teeth which may lead to erosion, sensitivity and caries susceptibility.