Chitosan-Based Film of Tyrothricin for Enhanced Antimicrobial Activity against Common Skin Pathogens Including Staphylococcus aureus.

Chitosan-based film-forming gel is regarded as a promising vehicle for topical delivery of antimicrobial agents to skin wounds, since it protects from microbial infection and the cationic polymer itself possesses antibacterial activity. In this study, possible synergistic interaction against common skin pathogens between the cationic polymer and tyrothricin (TRC), a cyclic polypeptide antibiotic, was investigated, by determining the concentration to inhibit 90% of bacterial isolates (MIC). The addition of the polysaccharide to TRC dramatically reduced the MIC values of TRC by 1/33 and 1/4 against both methicillin-resistant and methicillinsusceptible Staphylococcus aureus, respectively. The synergism of TRC and chitosan combination against both strains was demonstrated by the checkerboard method, with a fractional inhibitory concentration index below 0.5. Moreover, co-treatment of TRC and chitosan exhibited antibacterial activity against Pseudomonas aeruginosa, due to the antibacterial activity of chitosan, whereas TRC itself did not inhibit the gram-negative bacterial growth. These findings suggested that the use of chitosan-based film for topical delivery of TRC could be an alternative to improve TRC antimicrobial activity against strains that are abundant in skin wounds.

Wound healing efficacy of a chitosan-based film-forming gel containing tyrothricin in various rat wound models.

The objective of this study was to evaluate the healing effects of a chitosan-based, film-forming gel containing tyrothricin (TYR) in various rat wound models, including burn, abrasion, incision, and excision models. After solidification, the chitosan film layer successfully covered and protected a variety of wounds. Wound size was measured at predetermined timepoints after wound induction, and the effects of the film-forming gel were compared with negative (no treatment) and positive control groups (commercially available sodium fusidate ointment and TYR gel). In burn, abrasion and excision wound models, the film-forming gel enabled significantly better healing from 1 to 6 days after wound induction, compared with the negative control. Importantly, the film-forming gel also enabled significantly better healing compared with the positive control treatments. In the incision wound model, the breaking strength of wound strips from the group treated with the film-forming gel was significantly increased compared with both the negative and positive control groups. Histological studies revealed advanced granulation tissue formation and epithelialization in wounds treated with the film-forming gel. We hypothesize that the superior healing effects of the film-forming gel are due to wound occlusion, conferred by the chitosan film. Our data suggest that this film-forming gel may be useful in treating various wounds, including burn, abrasion, incision and excision wounds.

Efficacy of a tyrothricin-containing wound gel in an abrasive wound model for superficial wounds.

BACKGROUND: Topical preparations are a common treatment for superficial acute wounds, which at the least do not interfere with healing and ideally result in enhanced wound healing irrespective of microbial colonization. OBJECTIVE: To examine the effects of a topical antimicrobial gel and its vehicle on the wound healing of standardized, superficial abrasions. METHODS: Thirty-three healthy volunteers were enrolled in a double-blinded, randomized, intraindividual comparison study. Three standardized, superficial abrasions were induced on their forearms. A tyrothricin 0.1% gel (Tyrosur® gel; Engelhard Arzneimittel GmbH & Co. KG, Niederdorfelden, Germany) and its vehicle were randomly applied to two of the test areas, and one lesion remained untreated. RESULTS: A significant improvement of wound healing was seen with both tyrothricin 0.1% gel and its corresponding vehicle in the clinical assessment. The mean area under the curve (AUC) of wound healing scores was the same for both preparations and the mean reepithelization scores were comparable at all test points over the entire 12 days. A lower mean AUC representing less reepithelization was found for the untreated test fields. CONCLUSION: The use of tyrothricin 0.1% gel and its corresponding vehicle resulted in statistically significant improved wound healing with an earlier onset of healing in particular. Based on these results obtained using an abrasive wound model, it can be concluded that the addition of tyrothricin 0.1% to the gel vehicle did not interfere with the improved wound healing seen with the vehicle alone.

Evaluation of topical pharyngeal anaesthesia by benzocaine lozenge for upper endoscopy.

BACKGROUND: Among the randomized controlled trials evaluating the effect of pharyngeal anaesthesia only some suggest benefit. Spray is irritating for some people and leaves bitter taste in the throat. We hypothesized that delivering the local anaesthetic as a sucking lozenge would benefit the patients in terms of decreasing anxiety and will improve procedure performance and patient tolerance. AIM: To determine whether benzocaine/tyrothricin sucking lozenges with conscious sedation is superior to conscious sedation alone, with respect to procedure performance and tolerance in patients undergoing upper endoscopy. METHODS: One hundred and seventy-four adult patients undergoing upper endoscopy with conscious sedation completed the study. They were randomized to receive sucking lozenge containing benzocaine or placebo before the procedure. Patients were asked to rate prestudy anxiety, tolerance for topical pharyngeal anaesthesia, comfort during endoscopy, degree of difficulty of intubation, postprocedure throat discomfort and willingness to undergo subsequent examinations using a 10-cm visual analogue scale. Endoscopists were asked to estimate the ease of oesophageal intubation and procedure performance. RESULTS: No significant statistical differences regarding all the points studied were found between the groups. CONCLUSIONS: Topical pharyngeal anaesthesia with benzocaine/tyrothricin lozenges with conscious sedation has no advantages over conscious sedation alone in patients undergoing upper endoscopy.

[Tyrothricin powder in the treatment of cutaneous lesions]. / Tyrothricin-Puder bei Hautverletzungen. Reduktion des Wundradius bei infizierten und infektionsgefährdeten Wunden--Eine randomisierte, placebokontrollierte Doppelblind-Studie.

BACKGROUND AND OBJECTIVES: The efficacy and tolerance of an antiseptic wound powder based on the antibiotic tyrothricin was investigated in a prospective, randomized multicenter trial in patients with posttraumatic and surgical cutaneous lesions. PATIENTS AND METHODS: In 5 centers, 131 male and female patients from 18-85 years were included with posttraumatic or surgical cutaneous lesions with infection or in danger of infection (area > or = 200 mm2). In a double-blind study, tyrothricin (n = 62; 0.1 g tyrothricin per 100 g of vehicle) or placebo powder (n = 69) was applied to the wound twice daily for 9 days. The primary aim was to evaluate the average daily reduction of the radius from the lesion area between the start and end of the randomized treatment (alpha = 0.025; one-sided). Secondly, a wound index (range 0-15) was calculated from the assessments of rubor, crusting, exudation, pain and functional impairment. RESULTS: The treatment groups were comparable at baseline. During randomized treatment, the radius of the lesions was reduced at an average of 0.55 +/- 0.31 mm/day (mean +/- SD) for tyrothricin and 0.47 +/- 0.30 mm/day for placebo (p = 0.016; one-sided; intention-to-treat data set). The wound index decreased at an average of 4.2 +/- 1.7 and 3.3 +/- 1.9 points for tyrothricin and placebo, respectively (p = 0.0048; one-sided). 4 adverse events occurred in each group. A causal relationship with the investigational drug could not be excluded in 3 of the placebo group. CONCLUSION: The results confirm the tendency to an acceleration of wound healing by tyrothricin powder (Tyrosur Powder) in case of infection or danger of infection. A superior efficacy compared to placebo was demonstrated. Due to its good tolerability and the absence of a systemic effects tyrothricin powder is appropriate for the treatment of superficial skin lesions.

[The effect of a formaldehyde-tyrothricin combination placed in periodontal pockets in association with scaling and root planing]. / Evaluation de l'activité d'une association "formaldéhyde-tyrothricine" instillée dans les poches parodontales en complement du detartrage-surfaçage.

A solution of formaldehyde and tyrothricin was placed in periodontal pockets of 14 patients. One maxillary quadrant was used as the experimental side, while the contralateral quadrant was employed as the control. A placebo solution was placed in the pockets of the control side. Both the experimental and control sides were treated on days -3, 0, +4, +7, +11 and +14. Scaling and root planing was accomplished on day 0. Plaque and gingival indices, and gingival fluid volume were recorded on all of the treatment days, as well as on day +28. Pocket depths were noted on days -3, 0, +14 and +28. Improvements were noted in all parameters measured on both the experimental and control sides, although statistical analyses revealed that plaque and gingival indices were slightly better in the experimental side. The author concludes that placing a Formaldehyde-Tyrothricin solution in periodontal pockets offers some therapeutic gain over scaling and root planing alone.

Salivary levels of gramicidin after use of a tyrothricin-containing gargle/mouth-wash and tyrothricin lozenges.

Three pharmaceutical preparations for the disinfection of the oropharynx were tested with regard to the gramicidin concentration obtained in the saliva after their appropriate application. Peak values followed a dose-concentration relationship and were highest after sucking a lozenge containing 10 mg tyrothricin (mean 109.3 mg/L) followed by that of a gargle/mouth-wash containing 667 mg tyrothricin/L (mean 21.1 mg/L) and of a lozenge containing 4 mg tyrothricin (mean 14.4 mg/L).

Salivary levels of gramicidin after use of a tyrothricin lozenge and a tyrothricin gargle/mouth-wash.

Salivary levels and total salivary recovery of gramicidin were determined by high performance liquid chromatography in healthy volunteers after administration of a tyrothricin lozenge and a tyrothricin gargle/mouth-wash. Average peak values of gramicidin after sucking the lozenge were 37.5 mg/l and were usually reached within the five minutes. After use of the lozenge mean total recovery of gramicidin in saliva was 44% within the first 30 minutes. After application of the gargle/mouth-wash about 11% was retained in the oral cavity and excreted with saliva within the following 30 minutes. The implications of these findings are discussed.

[Bioavailability and local anesthetic effect of the combination of tyrothricin, fomocain, diphenhydramine and 8-hydroxyquinoline in a gel preparation for burns and wounds]. / Bioverfügbarkeit und lokalanästhetische Wirkung eines Brand- und Wundgels in der Kombination von Tyrothricin, Fomocain, Diphenhydramin und 8-Hydroxychinolin.

The biological availability was investigated of diphenhydramine and fomocaine, two of the active principles of the new formulation "Herit" used as a jelly against burns and small wounds. Fomocaine and diphenhydramine penetrate deeply into stratum corneum. The addition of fomocaine guarantees a quick pain relieving effect on the damaged skin. The jelly does not retain diphenhydramine and fomocaine.

A double-blind comparative study of Otoseptil Ear Drops and Otosporin Ear Drops in otitis externa.

A double-blind comparative study of Otoseptil Ear Drops and Otosporin Ear Drops in otitis externa in fifty-eight patients revealed them both to be equally effective in a series with very few fungal infections. In view of the normally high proportion of infections including fungi, there are obvious advantages in using Otoseptil Ear Drops.