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Changing pH in botulinum toxin Type B reduced injection pain

By changing the pH level in the acidic solution of botulinum toxin Type B, injection pain was reduced and efficacy was not compromised, according to study results.

Researchers used reviewed clinical evaluation data and computer analysis of photographs to confirm the efficacy of different dilutions of botulinum toxin Type B (BTX-B) and to confirm botulinum toxin Type A (BTX-A) resistance in a series of three patients. The study involved the use of BTX-B (usually pH 5.6) that was diluted with sodium bicarbonate to normalize the pH to 7.5 in syringe immediately before injection. The different pH BTX-B solutions were then compared through pain assessment, with physician scoring for efficacy.

Two patients (1 man) who developed acquired BTX-A resistance agreed to be treated with three commercially available Type A toxins, which were used to confirm resistance to BTX-A in upper facial muscles. They were then treated with BTX-B, to which they responded. The BTX-B formula changed to pH 7.5 significantly reduced pain in the injection site, with retained efficacy during 10 weeks, according to the researchers.

Disclosure: The authors have no relevant financial disclosures.