Bacteriostatic preserved saline for pain-free periocular injections: review

Abstract

We review evidence regarding the use of 0.9% benzyl alcohol in 0.9% sodium chloride solution for periocular injections (‘preserved saline’) including botulinum toxin A injections and local anaesthesia. A literature search was undertaken using search terms ‘bacteriostatic saline’, ‘benzyl-alcohol saline’, ‘benzyl alcohol sodium chloride’ and ‘preserved saline’. Bibliographies identified further sources. There have been 62 studies published on the subject of preserved-saline since 1928. Significantly lower injection-associated pain levels for periocular/facial botulinum toxin injections reconstituted with preserved-saline rather than preservative-free saline are reported by 5 studies. Significantly lower injection-associated pain with preserved-saline diluted lidocaine and epinephrine solution for eyelid anaesthesia compared with unmodified or buffered lidocaine with epinephrine, and adequate anaesthesia, was reported by one study. Thirty-one studies have explored preserved-saline for anaesthetic and seven for bacteriostatic properties, with very low infection rates after periocular botulinum toxin injections, and reduced rates of infection in indwelling catheters when preserved saline is used to flush. A meta-analysis concluded that lidocaine-containing solutions are more effective at reducing pain from insertion of intravenous catheters. Patient-perceived pain related to periorbital injections of local anaesthesia is reduced when the anaesthetic is diluted with benzyl alcohol-preserved saline compared with other dilution or buffering options. Pain is similarly reduced for periocular botulinum toxin injections reconstituted with preserved saline compared with unpreserved saline. Benzyl-alcohol preserved-saline is inexpensive but costlier than unpreserved-saline, with minimal reported complications, particularly with periocular administration, and offers the opportunity to improve the patient experience.

A clinical study of using a phentolamine alcohol wet dressing in the treatment of extravasation after a 20% fat emulsion intravenous infusion - a randomised trial

“…A hydropathic compress of alcohol has an anaesthetic effect on local tissues and nerves, thus reducing the pain suffered by patients. Furthermore, alcohol is a bacteriostatic drug, which can prevent local tissue infection and reduce local reaction [18].…”

Office-based Blepharoplasty

“…Dilution with bacteriostatic saline consisting of 0.9% benzyl alcohol in 0.9% sodium chloride is shown to reduce patientperceived pain related to periorbital injections of local anesthetic and improve comfort better than buffering with 8.4% sodium bicarbonate. [5][6][7][8][9] Bacteriostatic saline has no impact on the potency of epinephrine in terms of duration of action or vasoconstriction and can be added to any local anesthetic without the formation of precipitate. There are a number of additional advantages to this approach, including: 1.…”

“…The authors have used a protocol for over 20 years in which standard 2% lidocaine with 1:100,000 epinephrine is diluted 1:5 with plain or bacteriostatic saline for an initial injection that attempts to fully anesthetize all surgical sites. Dilution with bacteriostatic saline consisting of 0.9% benzyl alcohol in 0.9% sodium chloride is shown to reduce patient-perceived pain related to periorbital injections of local anesthetic and improve comfort better than buffering with 8.4% sodium bicarbonate 5–9 . Bacteriostatic saline has no impact on the potency of epinephrine in terms of duration of action or vasoconstriction and can be added to any local anesthetic without the formation of precipitate.…”

Biochemical Stability and Microbial Control of Reconstituted DaxibotulinumtoxinA-lanm for Injection

“…In clinical trials for BoNTA product approvals, the products are reconstituted in normal (unpreserved) saline (0.9% NaCl) as reflected in the product labeling [ 1 , 3 ]. However, in clinical practice, it is common for injectors to reconstitute botulinum toxins in preserved saline (i.e., bacteriostatic saline: 0.9% NaCl preserved with benzyl alcohol) [ 4 ], as it has been found that this results in less procedural pain than when BoNTA is reconstituted in unpreserved saline [ 5 , 6 , 7 , 8 , 9 ]. The product’s stability and sterility after reconstitution are influenced by the excipients formulated with the active pharmaceutical ingredient, in addition to the diluent.…”