Development of a liquid enzyme-based ceruminolytic product

Evaluation of the safety and efficacy of a novel product for the removal of impacted human cerumen

Background

This open-label study evaluated the safety and efficacy of a novel product for the removal of impacted cerumen in adult patients.

Methods

This was a prospective, single-center, single-arm, self-controlled clinical trial conducted in a community general practice setting. The novel product contains glycolic acid in an otologically-acceptable buffer containing sodium bicarbonate and glycerin and other buffering agents. The product was instilled into the ear canal prior to irrigation with warm water. Severity of cerumen impaction was graded using a 5-point scale. Improvement in tympanic membrane visualization was assessed after instillation and irrigation.

Results

A majority (83%, 25/30) of ears showed improvement with one application: with 53% (16/30) totally dissolved and gained 100% TM visualization. Total dissolution was observed in 80% (24/30) of the study ears per the intent-to-treat analysis and 86% (24/28) if irrigation instructions were followed. Most of the ears/participants that had cerumen blockage symptoms experienced significant improvement with the application. Feelings of fullness disappeared in 92% (11/12) of the affected ears; ears itching, 91% (10/11); water trapping or cracking, 78%, and decreased hearing disappeared in 71% (10/14). All (100%, 18) of the participants who completed the application satisfaction assessment were satisfied with the application process in terms of time needed and the overall rinse procedure. Only one mild adverse event (ear pruritis) occurred that was related to application.

Conclusions

The tested cerumen removal product was effective and safe for removing moderate to severe blockage in patients with impacted cerumen. Procedure satisfaction for the product was high.

Trial Registration

This trial is registered on http://www.clinicaltrials.gov/. The registration number is NCT02829294. The trial was retrospectively registered on July 8, 2016.

Stability improvement of a liquid enzyme product

The shelf-life of a previously developed two-part liquid-liquid enzyme ceruminolytic product was improved maintaining the same final reconstituted composition and re-formulating the liquid enzyme portion as a drug granulate by a double wet granulation process. The critical steps for the preparation of the granulate were studied (mixing/granulating times and drying) determining the proteolytic activity, the residual ethanol, and the moisture content of the granulates. The original liquid-liquid formulation had been proven effective as a ceruminolytic agent, but only had stability of greater than 75% enzyme activity for up to 18 months and up to 1 day at room temperature after combining the two parts. The resulting improved product was proven to be stable for up to 24 months at 30 degrees C, and up to 3 days at room temperature after combining the two parts. Therefore, maintaining the enzyme in a granulated form until reconstitution afforded an improvement in stability compared with the original two-part liquid-liquid formulation.