Benzocaine Gel Toothache Dose-Response Study

Introduction

Topical benzocaine is currently marketed in 10% and 20% formulations by Wyeth Consumer Healthcare and Del Pharmaceuticals, Inc. for relief of toothache. The ingredient has been assigned monograph status as an external anesthetic/analgesic for the temporary relief of pain due to minor irritation or injury of the mouth and gums, minor dental procedures, dentures, orthodontic appliances, canker sores and teething, sore mouth and sore throat (Notice of Proposed Rulemaking for OTC Oral Health Care Drug Products Amendment to include Relief of Oral Discomfort Products [Docket #81N-0033] published on September 24, 1991 [Federal Register 56(185: 48302-47]). However, the Food and Drug Administration (FDA) concluded that the available data were not adequate to establish the effectiveness of benzocaine for the relief of toothache and did not assign monograph status to benzocaine for this indication.

Wyeth Consumer Healthcare and Del Pharmaceuticals, Inc. submitted the results of eight efficacy studies and one animal safety study to the FDA, which were conducted between 1980-1994 to support the efficacy of the ingredient for this indication. The Agency’s response, received in July 1998 noted that “there is some evidence in the data submitted, along with the data contained in the literature, to support the effectiveness of benzocainecontaining gel applied to the tooth cavity for the initial relief of severe and moderate toothache.” The Agency requested that an additional study be conducted to determine the efficacy of the agent for this indication, and to assess whether a dose-response exists between 10% and 20% benzocaine. In addition, the Agency stipulated that a label be developed that assured safe dosing for temporary relief of toothache pain. The present double-blind, placebo-controlled randomized study will determine the efficacy and the dose-response trend between 10% and 20% benzocaine gel for relieving toothache, and will also help ensure the label directions are adequate in terms of instructing the subjects on the safe use of the product.

Objectives

The objectives of this study are:

1. To evaluate the efficacy and safety of 10% and 20% benzocaine gel for the relief of toothache, compared to placebo and to each other.
2. To assess the subject’s compliance with the dosing directions on the proposed label.