| The cosmetic form of botulinum toxin, often | | | | December 1989 as an orphan drug for the |
| referred to by its product name Botox, is a | | | | treatment of strabismus, hemifacial spasms, |
| popular non-surgical injection that | | | | and blepharospasm. BOTOX is distributed in |
| temporarily reduces or eliminates frown | | | | 100-unit vials.The original batch of |
| lines, forehead creases, crows feet near the | | | | neurotoxin prepared by Shantz in November |
| eyes and thick bands in the neck. The toxin | | | | 1979 (designated batch 79-11) constituted the |
| blocks the nerve impulses, temporarily | | | | original BOTOX formulation and was used until |
| paralyzing the muscles that cause wrinkles | | | | December 1997. It was replaced by a new |
| while giving the skin a smoother, more | | | | neurotoxin complex batch designated BCB 2024. |
| refreshed appearance. Studies have also | | | | The new bulk batch is 5-6 times more potent |
| suggested that Botox is effective in | | | | on a weight basis. In a 100-unit vial, only |
| relieving migraine headaches, excessive | | | | 4.8 ng of neurotoxin is needed compared to 25 |
| sweating and muscle spasms in the neck and | | | | ng of 79-11. The new BOTOX is comparable in |
| eyes. Botulinum neurotoxin is produced by the | | | | clinical efficacy and safety to the old, and |
| gram-negative anaerobic bacterium Clostridium | | | | a unit dose of new BOTOX provides an |
| botulinum. | | | | equivalent response to the same unit dose of |
| | | | old BOTOX. Hopefully, the reduced protein |
| Eight serologically distinct botulinum | | | | load of the new BOTOX leads to reduced |
| neurotoxins exist, designated as A, B, C1, | | | | immunogenicity and a lower incidence of |
| C2, D, E, F, and G. Seven are associated with | | | | neutralizing antibody formation.Dysport is |
| paralysis. Types A, B, E and, rarely, F and G | | | | another formulation of botulinum toxin type A |
| are associated with human botulism.The dose | | | | available in Europe and a few other |
| of botulinum toxin is expressed in mouse | | | | countries. It is prepared using column-based |
| units. One unit is equal to the amount that | | | | purification techniques and distributed in |
| will kill 50% of a group of 18- to 22-g Swiss | | | | 500-unit vials that can be stored at room |
| Webster mice when injected intraperitoneally. | | | | temperature. BOTOX and Dysport are both |
| The human lethal dose (LD) for BOTOX | | | | botulinum toxin type A preparations but are |
| (botulinum type A purified neurotoxin | | | | quite distinct from one another. BOTOX is |
| complex) is estimated at approximately 3000 | | | | approximately 4 times more potent on a per |
| units. BOTOX injections of less than 100 | | | | unit basis, and Dysport doses often are |
| units usually are used for cosmetic purposes | | | | approximately 4 times the BOTOX doses used to |
| and of less than 300-600 units for other | | | | generate a similar clinical effect. |
| purposes, thereby allowing a wide safety | | | | Differences in these toxins may relate to |
| margin. Recognizing that doses are not | | | | differences in the strain of bacterium, |
| interchangeable among different formulations | | | | preparation, diffusion, and potency |
| of botulinum toxin (BOTOX, Dysport, Myobloc) | | | | testing.Myobloc is a botulinum toxin type B |
| is important; to achieve similar clinical | | | | preparation currently in clinical trials. It |
| effects, different doses are used.BOTOX is a | | | | is anticipated that it will be distributed as |
| sterile lyophilized form of botulinum toxin | | | | a solution. Little information is available |
| type A. It is produced from a culture of the | | | | concerning the cosmetic use of Dysport and |
| Hall strain of C botulinum and purified by a | | | | Myobloc. The remainder of this article |
| series of acid precipitations to a | | | | therefore focuses on BOTOX, and all unit |
| crystalline complex containing the toxin and | | | | doses refer to BOTOX unless otherwise |
| other proteins. The FDA approved BOTOX in | | | | specified. |