# Is Cold Storage Still a Must? Evaluating Room‐Temperature OnabotulinumtoxinA for Glabellar Lines Treatment

## TL;DR

This study shows that OnabotulinumtoxinA stored at room temperature for up to 7 days remains effective and sterile for treating glabellar lines.

## Contribution

The study provides evidence that room-temperature storage of reconstituted OnabotulinumtoxinA does not compromise its sterility or clinical effectiveness.

## Key findings

- No microbial growth was observed in BoNT-A stored at 37°C for 60 days.
- Both groups showed significant improvements in wrinkle severity and muscle activity.
- Patients receiving BoNT-A after 7 days at room temperature reported higher satisfaction.

## Abstract

New botulinum toxin type A (BoNT‐A) formulations eliminated cold‐chain storage before reconstitution. Nonetheless, concerns remain about BoNT‐A properties when stored at room temperature after reconstitution.

This study aimed to evaluate the sterility and effectiveness of BoNT‐A storage at room temperature in glabellar wrinkles.

BoNT‐A (Allergan Botox, Brazil) was reconstituted and maintained in a stove at 37°C for 60 days and then tested for sterility according to the Pharmacopeia guidelines. Then, sixty patients aged 25–60 years were divided into two groups: Group 1 (G1) received BoNT‐A immediately after reconstitution, and Group 2 (G2) received BoNT‐A after 7 days at room temperature. Participants were assessed for wrinkle severity using the Merz Scale, satisfaction with treatment using the Face‐Q scale, and muscle activity by electromyography. Data were collected before injections and after 15, 30, 60, and 90 days.

Absence of turbidity evidenced no microbial growth in all periods analyzed. Both groups showed significant reductions in glabellar contraction (p < 0.001), wrinkle severity (p < 0.05), and improved satisfaction. G1 presented lower wrinkle severity, while G2 reported higher satisfaction (p < 0.05).

Room temperature and longer storage periods may not affect OnabotulinumtoxinA sterility and clinical results.