Antimicrobial effectiveness of cetylpyridinium chloride and zinc chloride-containing mouthrinses on bacteria of halitosis and peri-implant disease

PURPOSE

To clarify the antimicrobial efficacy of zinc chloride (ZnCl2) and cetylpyridinium chloride (CPC) by testing their impact on the growth of seven bacterial strains known to be involved in the pathophysiology of both peri-implant disease and halitosis-Staphylococcus aureus, Streptococcus mutans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Treponema denticola, and Tannerella forsythia.

MATERIALS AND METHODS

A time-response growth curve was obtained. Commercial mouthrinses with CPC, ZnCl2, or both were added to the media in a final concentration of 0.25% CPC, 2.5% ZnCl2, and 2.5% ZnCl2 with 0.25% CPC.

RESULTS

Both CPC and ZnCl2 effectively inhibited the growth of almost all bacterial strains tested except T denticola. ZnCl2 was generally more effective in suppressing bacterial growth than CPC. ZnCl2 with CPC showed the greatest inhibitory activities on almost all strains of bacterial growth except for P gingivalis and T denticola, followed by ZnCl2, then CPC, thus suggesting the possibility of a synergistic effect of the two agents. P gingivalis exhibited a different pattern because ZnCl2 showed the most significant inhibitory effect. CPC did not show growth inhibitory effects on T denticola, but ZnCl2 did.

CONCLUSION

Zinc and CPC effectively inhibit bacterial growth that causes both halitosis and peri-implant disease. The effect is even more powerful when applied in combination.

Interference of Antimicrobial Activity of Combinations of Oral Antiseptics Against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus

PURPOSE

The purpose of this study was to compare the effects of combinations of sodium fluoride and antiseptic compounds on the growth of Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus.

METHODS

The agar diffusion assay was used to determine bacterial growth inhibition.

RESULTS

Of the combinations tested, 0.1 percent sodium fluoride and five percent povidone iodine produced synergistic antibacterial effects against S. mutans and S. sanguinis. The combination of 10 percent povidone iodine and 0.5 percent sodium hypochlorite produced additive antibacterial effects against L. acidophilus. Interference was seen in some combinations such as 0.01 percent chlorhexidine and 0.25 percent sodium lauryl sulphate, 0.5 percent sodium hypochlorite and 10 percent povidone iodine, and 0.01 percent cetyl pyridium chloride and 0.1 percent sodium fluoride. However, 0.1 percent sodium fluoride combined with 0.01 percent chlorhexidine did not interfere with the antibacterial effects of chlorhexidine against S. mutans or S. sanguinis.

CONCLUSIONS

Combinations of common antiseptics and fluoride compounds can produce interference, synergistic, or additive effects. The combination of 0.1 percent sodium fluoride and five percent povidone iodine had the greatest potential for suppression of S. mutans.

Effectiveness of a Chlorhexidine Digluconate 0.12% and Cetylpyridinium Chloride 0.05% Solution in eliminating Candida albicans Colonizing Dentures: A Randomized Clinical in vivo Study

BACKGROUND

Effective denture hygiene is important for patients suffering from denture stomatitis (DS). This study aimed to evaluate the efficacy of a solution containing 0.12% chlorhexidine (CHX) digluconate and 0.05% cetylpyridinium chloride (CPC) in eliminating Candida albicans colonizing dentures.

MATERIALS AND METHODS

Forty denture wearers (11 men, 29 women; age range 40 to 80 years) with clinical evidence of DS were randomly divided into two groups, one test and one control. The dentures of the test group were treated by immersion in a solution of 0.12% CHX and 0.05% CPC while those of the control group were immersed in distilled water. Swabs were collected from the fitting surfaces of the upper dentures prior and post cleaner use and examined mycologically.

RESULTS

Reduction in the number of colony-forming units (CFU) of Candida albicans after immersion of the dentures in a solution of 0.12% CHX and 0.05% CPC was significantly greater than that of the control group.

CONCLUSION

A solution of 0.12% CHX and 0.05% CPC tested as a product of disinfection of the acrylic dentures showed significant results after immersion of 8 night hours for 4 days.

The effect of a mouthrinse containing chlorine dioxide in the clinical reduction of volatile sulfur compounds

This study sought to evaluate the clinical effect of a mouthrinse containing 0.3% chlorine dioxide (ClO2) in reducing oral volatile sulfur compounds (VSC). Halitosis was induced by L-cysteine in 11 volunteers, and 4 solutions were compared: a test solution containing 0.3% ClO2, 0.07% cetylpyridinium chloride (CPC), and 0.05% sodium fluoride; a placebo; a solution containing 0.05% CPC; and a control solution of 0.2% chlorhexidine gluconate (CHX). VSC levels were assessed using a Halimeter, and 6 measurements were made from baseline to 3 hours postrinse. The VSC reduction rate of the test mouthrinse was superior to the placebo and the CPC solution. There was no difference between the test solution and the CHX solution in VSC reduction rates immediately postrinse, or at 2 and 3 hours postrinse; both solutions were statistically superior to the placebo and the CPC solution.

Efficacy of antiplaque mouthwashes: a five-day clinical trial

The aim of this study was to evaluate and compare the efficacy of antiplaque mouthwashes. Plaque levels were determined by applying a plaque-disclosing solution using the Turesky et al modification of the Quigley Hein plaque index. The control group (n = 6) brushed twice per day with fluoride toothpaste for one minute and rinsed with water, while the study groups (n = 6) brushed once per day with fluoride toothpaste for one minute, followed by rinsing with 5.0 mL of mouthwash diluted with 10.0 mL of water for 30 seconds. The control group brushed and rinsed with water twice per day. The results indicated that cetylpyridinium chloride in combination with sodium fluoride offered maximum plaque inhibition, followed by chlorhexidine gluconate and sodium monofluorophosphate, while plaque levels increased in the control group and with the combination of chlorhexidine gluconate and sodium fluoride. The only antiplaque agents to demonstrate a statistically significant difference from the control were cetylpyridinium chloride in combination with sodium fluoride, and chlorhexidine gluconate. Increasing the fluoride concentration had no impact on antiplaque activity.

In vitro antibacterial efficacy of cetylpyridinium chloride-containing mouthwashes

OBJECTIVE

The objective of this study was to examine the ability of three CPC-containing mouthwashes to kill planktonic bacteria in an in vitro short-exposure assay.

METHODS

This blind study was conducted on two common oral bacterial species: Aggregatibacter (Actinobacillus) actinomycetemcomitans and Streptococcus mutans. The following mouthwashes were tested: two containing 0.075% CPC and 0.05% NaF in an alcohol-free base, and one containing 0.075% CPC and 0.05% NaF plus 6% alcohol. Additionally, a 0.05% NaF-only mouthwash was included as a negative control. Bacteria were exposed to one of the test mouthwashes for 30 seconds and then washed thoroughly, serially diluted, and plated on appropriate media to determine viable bacterial counts. Viable counts were converted to a log reduction in colony forming units (CFUs) relative to the negative control.

RESULTS

All three test mouthwashes included in this study gave a statistically significant reduction of > 3 log CFUs relative to samples treated with the negative control.

CONCLUSION

All three experimental 0.075% CPC mouthwash formulas gave a > 99.9% reduction in viable bacteria of both species following 30 seconds of treatment.

Efficacy of an alcohol-free CPC-containing mouthwash against oral multispecies biofilms

OBJECTIVE

The aim of this work was to develop two static-model multispecies oral biofilm systems to compare the efficacy of a placebo mouthwash to an alcohol-free mouthwash containing 0.075% CPC.

METHODS

Two model biofilm systems were used: a 24-well glass-bottom microplate (GM) system and a chamber slide (CS) system. These were inoculated with Schaedler media containing pooled, unfiltered saliva. During incubation at 37 degrees C in 5% CO2, Schaedler media was replaced every 24 hours. Five-day and 10-day multispecies biofilms in the GM and CS systems were then exposed to phosphate buffered saline, the placebo mouthwash, or the alcohol-free 0.075% CPC-containing mouthwash. Biofilms were visualized in three-dimensions by Confocal Laser Scanning Microscopy (CLSM), and fluorometric analyses were performed on biofilms in the GM system.

RESULTS

CLSM demonstrated that regardless of the model system used, the alcohol-free 0.075% CPC-containing mouthwash solution increased the number of damaged biofilm cells. The efficacy of CPC was inversely related to the age of the biofilm. A contrariety between the two biofilm systems was that the CS system indicated that alcohol-free 0.075% CPC-containing mouthwash partially disrupted biofilms. Fluorometric analysis ofGM biofilms also demonstrated that the alcohol-free 0.075% CPC-containing mouthwash damaged biofilm cells.

CONCLUSION

Two static oral multispecies model biofilms systems demonstrated that an alcohol-free 0.075% CPC-containing mouthwash had greater antimicrobial efficacy than a placebo mouthwash. The alcohol-free 0.075% CPC-containing formulation is effective against multispecies oral biofilms.

Superiority of an essential oil mouthrinse when compared with a 0.05% cetylpyridinium chloride containing mouthrinse: a six-month study

OBJECTIVE

To evaluate the antiplaque/antigingivitis effectiveness of an essential oils containing mouthrinse as compared to a 0.05% cetylpyridinium chloride mouthrinse.

METHOD

Generally healthy subjects with mild to moderate levels of plaque and gingivitis participated in a 6-month, examiner-blind, single centre, randomised, parallel-group controlled clinical trial. They were randomised into three mouthrinse groups--control (C), 0.05% cetylpyridinium chloride (CPC), or a fixed combination of essential oils (EO). Subjects received a dental prophylaxis at baseline and rinsed twice daily in addition to their usual oral hygiene for six months. Plaque Index and Modified Gingival Index were determined at 3 and 6 months.

RESULTS

At 6 months, the EO group exhibited statistically significantly lower mean scores for MGI and PI than CPC (32.4% and 56.2% reductions, respectively). Compared to control, EO provided statistically significantly lower mean MGI and PI scores (36.3% and 69.7 %, respectively). The CPC group showed statistically significantly lower mean MGI and PI scores than the C group (5.8% and 30.7%, respectively).

CONCLUSION

This study demonstrated the superiority of an EO rinse compared to a 0.05% CPC rinse in reducing plaque and gingivitis and confirmed that the daily use of an EO containing mouthrinse can provide a clinically significant benefit in reducing plaque and gingivitis.

Antiplaque/antigingivitis efficacy and safety of a cetylpyridinium chloride/zinc gluconate mucoadhesive gel. Results of a 6-month clinical trial

This article presents the results of a controlled clinical trial evaluating a new at-home treatment to improve gingival health. Designed for overnight application at the gingival margins and in the interproximal spaces, the product is a mucoadhesive gel containing 0.10% cetylpyridinium chloride (CPC) and 0.592% zinc gluconate (ZG). The authors assessed the efficacy and safety of the CPC/ZG gel in adults with low-to-moderate gingival and plaque index scores by comparing clinical and laboratory findings for subjects using the CPC/ZG gel with those for subjects using the control gel (0% CPC and 0.592% ZG). Clinical findings at 3 and 6 months showed statistically significant improvements in two of the three major indices of gingival health in the CPC/ZG group compared with the control group. The performance of the treatment gel was supported by results of microbial analyses of plaque samples.

In vivo antiplaque efficacy of combined antimicrobial dentifrice and rinse hygiene regimens

PURPOSE

To evaluate using digital plaque image analysis the antiplaque efficacy of oral care regimens including use of antimicrobial toothpaste in combination with antimicrobial mouthrinse.

METHODS

16 subjects completed the study protocol including: (1) initial treatment phase, all subjects used a standard sodium fluoride dentifrice with 2x/day brushing, (2) second treatment phase, subjects were randomized to two treatment groups: stannous fluoride/sodium hexametaphosphate dentifrice or sodium fluoride triclosan/copolymer dentifrice; (3) third treatment phase, the group using stannous fluoride dentifrice rinsed with alcohol-free cetylpyridinium chloride mouthrinse and the group using triclosan dentifrice rinsed with essential oil mouthrinse. During each phase, plaque levels were assessed in the morning before toothbrushing (AM), post-brushing in the morning (PB) and in the afternoon (PM).

RESULTS

Stannous fluoride dentifrice was superior to triclosan dentifrice in plaque growth inhibition between toothbrushing. Both mouthrinses provided additional plaque prevention benefits when used with antimicrobial dentifrices. The cetylpyridinium chloride mouthrinse and stannous fluoride dentifrice regimen was particularly effective, building accretive efficacy over time. Average plaque reductions exceeded 50% vs. sodium fluoride dentifrice alone. Chemotherapeutic dentifrices and rinses increase plaque control used alone and particularly in combination. The stannous fluoride-cetylpyridinium chloride regimen showed the greatest benefits.

The Effects of Antimicrobial Sprays and Mouthrinses on Supragingival Plaque Regrowth: A Comparative Study

BACKGROUND

Due to the side effects of chlorhexidine digluconate (CHX) mouthrinsing, a spray has been proposed as an alternative method of CHX delivery to the oral cavity. The aim of this study was to investigate the plaque inhibitory effects of CHX, cetylpyridinium chloride (CPC), and triclosan (TRN) delivered by sprays and mouthrinses.

METHODS

The study was an observer-masked, randomized cross-over design balanced for carryover effects, involving 15 healthy volunteers in a 4-day plaque regrowth model. Products being tested (0.2% CHX, 0.12% CHX, 0.05% CPC, and 0.03% TRN) were used both as sprays and mouthrinses. A saline solution served as a negative control. On day 1, subjects received professional prophylaxis, suspended oral hygiene measures, and commenced using their allocated products. On day 5, subjects were scored for disclosed plaque.

RESULTS

CHX sprays (P<0.01) were the most effective sprays in preventing plaque regrowth, without significant differences between the two concentrations tested (P>0.05). TRN spray showed a significant inhibition of plaque regrowth in comparison to the negative control (P<0.05). CPC spray did not differ from saline spray (P>0.05). A similar trend of efficacy was detected for rinses. Although the effect on plaque regrowth observed with CHX rinses was superior to that of CHX sprays (P<0.0003), the latter did not cause side effects (P>0.2).

CONCLUSIONS

These findings, together with those from clinical trials, suggest that the CHX-containing sprays may represent an effective alternative to CHX rinses when mechanical oral hygiene has to be avoided in restricted areas. On the contrary, the TRN and CPC sprays showed little or no plaque inhibitory effects.

A 6-month clinical study assessing the safety and efficacy of two cetylpyridinium chloride mouthrinses

PURPOSE

To evaluate the effects of two experimental cetylpyridinium chloride (CPC) mouthrinses containing 0.075% and 0.10% CPC on the development of gingivitis and plaque versus a placebo control over a period of 6 months.

METHODS

This was a randomized, single center, parallel group, double blind, positive and placebo controlled clinical trial. A 0.12% chlorhexidine rinse served as the positive control for validation of the methodology. At the beginning of the trial, 366 subjects were balanced and randomly assigned to treatment groups. Subjects received a dental prophylaxis and began rinsing twice a day with 15 ml of their assigned mouthwash for 30 seconds after brushing their teeth. Subjects were assessed for gingivitis and gingival bleeding by the Löe-Silness Gingival Index method and plaque by the Turesky modification of Quigley Hein Plaque Index at baseline and after 3 and 6 months of product use. Oral soft tissue health was also assessed.

RESULTS

After 3 and 6 months, subjects rinsing with either 0.075% or 0.10% CPC had significantly (P< 0.0001) less gingivitis, gingival bleeding, and plaque, on average, than those on placebo. The 6-month mean reductions in gingivitis, gingival bleeding, and plaque for the 0.075% and 0.10% CPC rinses versus placebo were 23%, 30% and 17%, and 20%, 27% and 19%, respectively. There was no statistically significant difference in efficacy between the two CPC mouthrinses. Reductions at 3 months were similar to those seen at 6 months. Significant benefits were observed with chlorhexidine, thereby validating the study.

CLINICAL SIGNIFICANCE

This study clearly demonstrates that CPC mouthrinses formulated to deliver therapeutic benefits when used twice daily can significantly prevent the development of gingivitis, gingival bleeding, and plaque over a 6-month period.

A 0.05% cetyl pyridinium chloride/0.05% chlorhexidine mouth rinse during maintenance phase after initial periodontal therapy

BACKGROUND

Chlorhexidine (CHX) mouth rinse/spray can still be considered the gold standard in the chemical prevention of plaque formation and development of gingivitis. The product unfortunately has some side effects, such as extrinsic tooth staining, poor taste, taste disturbance, sensitivity changes in tongue, pain and irritation because of the alcohol content. These side effects led to the search of new formulations.

METHODS

In this double-blind, randomized, long-term, parallel study, 48 moderate periodontitis patients rinsed for 6 months (starting immediately after a "one-stage, full-mouth" disinfection) with one of the following products: CHX 0.2%+alcohol (Corsodyl), CHX 0.05%+ cetyl pyridinium chloride (CPC) 0.05% and no alcohol (Perio-Aid Maintenance, a new formulation), or the placebo of the latter. After 1, 3 and 6 months a series of clinical and microbiological parameters were recorded for the supra- and subgingival area as well as for saliva.

RESULTS

Although there was a significant treatment impact (mechanical debridement) in all groups, both CHX solutions further decreased both plaque and gingivitis indices (p<0.001 and p<0.05, respectively), when compared with placebo. This was also reflected by additional reductions in the number of CFU/ml of aerobic and especially anaerobic species and by a suppression of Streptococcus mutans (versus an overgrowth for the placebo), in all niches. Differences between both CHX solutions were never encountered. The subjective ratings were slightly in favour of the new CHX-CPC formulation when compared with the other CHX-alcohol formulation, especially for taste of the product (p<0.05), but less impressive for the staining of teeth and tongue.

CONCLUSIONS

The results of this study demonstrated the potential of a new CHX 0.05%+CPC 0.05% non-alcoholic formulation as an effective antiplaque agent for long-term use with reduced subjective side effects.

Clinical trial of a novel interdental brush cleaning system

OBJECTIVE

This single-blind, five parallel-arm, four-week randomized clinical trial was designed to compare the efficacy of a 0.05% cetylpyridinium chloride gel-releasing interdental brush (IDB) with standard interproximal cleaning devices for plaque and gingivitis reduction, and decreased frequency in interproximal gingival bleeding.

METHODOLOGY

After consenting, participants meeting inclusion criteria brushed their teeth, received a baseline examination and a professional cleaning, and were then block-randomized into five groups, with the plaque level serving as the blocking variable. All five groups performed standard tooth brushing as a background regimen. Three of the groups were respectively assigned to one of three interdental brush regimens, the fourth group was assigned to a standard flossing regimen (positive control), and the fifth group was assigned to a standard tooth brushing only regimen (control). Clinical outcome data were collected at two and four weeks.

RESULTS

Of a total of 162 starting participants, 152 completed the study. There were no baseline differences among the five groups with respect to age, interproximal plaque score, interproximal gingivitis score, or percent of interproximal bleeding on probing. After two and four weeks, the 3 IDB groups exhibited 30-40 percent lower plaque levels than the control (p < 0.05). With respect to interproximal gingival scores, the active agent IDB group exhibited a statistically significant effect after two weeks, and all three IDB groups demonstrated significantly better outcomes after four weeks (p < 0.05). At two and four weeks, the three IDB groups demonstrated a greater reduction in interproximal bleeding points upon probing compared to the two control groups (p < 0.05). The group using the 0.05% cetylpyridinium gel-releasing IDB system did not demonstrate superior clinical results when compared to the two other IDB groups.

CONCLUSION

When compared to control and positive control interdental cleaning procedures, daily use of IDBs was effective in reducing interproximal plaque and gingivitis scores, as well as interproximal bleeding on probing. The benefits were evident at two weeks, but were more consistent after four weeks. The 0.05% cetylpyridinium gel-releasing IDB system did not appear to confer a consistently independent incremental benefit.

Reduction of salivary S. aureus and mutans group streptococci by a preprocedural chlorhexidine rinse and maximal inhibitory dilutions of chlorhexidine and cetylpyridinium

OBJECTIVES

Staphylococcus aureus and mutans group streptococci can cause, among many other diseases, infective endocarditis and postoperative infections. The reduction of the number of these microorganisms in the oral cavity prior to surgical procedures has been related to a decreased incidence of such occurrences. The aim of this study was to evaluate the effect of a single preprocedural rinse with 0.12% chlorhexidine solution (Periogard) on the salivary counts of S aureus and mutans group streptococci and determine maximal inhibitory dilutions (MID) of this and 0.05% cetylpyridinium chloride solution (Cepacol).

METHOD AND MATERIALS

Saliva was collected from 60 patients before and after 30-second mouthrinses with chlorhexidine and cultured in appropriate media. The number of microorganisms was calculated based on the colony-forming units (CFUs). For the in vitro MID determination, 25 strains of S aureus were seeded in the media containing one of the sequential dilutions of both antiseptics.

RESULTS

S aureus, Streptococcus mutans, and Streptococcus sobrinus were initially isolated from 45%, 63%, and 28% of the patients, respectively. After rinsing with chlorhexidine, the reductions in the CFUs were above 99% for all the studied microorganisms. In the MID determination, all isolates were inhibited with 1/20 and 1/80 dilutions of cetylpyridinium and chlorhexidine, respectively. Dose-response curves were obtained for both antiseptics.

CONCLUSION

Single preprocedural chlorhexidine mouthrinse is effective in reducing salivary microorganisms to levels currently considered safe to perform invasive procedures, and it is still effective in a 1:80 dilution.

Compressive strength of glass ionomer cements with dental antibacterial agents

Glass ionomer cements have been suggested for obturating carious teeth that have been prepared with dental hand instruments. In such cases, carious dentine may be inadvertently or deliberately left in situ. The residual bacteria may, over time, lead to secondary caries and restoration failure. Benefit may be gained from combining antibacterial agents with the glass ionomer cement to control residual bacteria. The aim of this study was to investigate the effects on the compressive strength of glass ionomer cement combined with oral antibacterial agents. Cationic antibacterial agents; chlorhexidine hydrochloride, cetylpyridinium chloride and cetrimide were added to the powder and benzalkonium chloride, a liquid, to the liquid of Fuji IX glass ionomer cement. These were prepared to concentrations of 1, 2 and 4 per cent by weight of the glass ionomer cement and compared to Fuji IX with no antibacterial agent. Test specimens were subjected to a compressive force to failure. Multiple analysis of variance showed highly significant reductions in compressive strength (p < 0.01) between the test materials and control group apart from one per cent benzalkonium chloride. Increasing concentration of the antibacterial agent had increasing adverse effects on the physical properties. The addition of the antibacterial agents tested to Fuji IX reduces the seven-day compressive strength which may affect the clinical performance of the material.

Optimisation of the time of milk sample decontamination with 0.75% cethylpirydinium chloride upon identification of Mycobacterium avium subsp. paratuberculosis

Isolation of MAP from biological material, including milk, is very difficult. No matter how the fresh milk is obtained, it contains a certain number of rapidly growing microorganisms. Therefore, the decontamination process is applied in the methods of MAP isolation. Investigations were therefore undertaken to determine the optimal time of milk sample decontamination with 0.75% CPC. The experiment was divided into two parts: determination of the survival time of M.smegmatis and E. coli in 0.75% CPC and determination of the time of raw milk decontamination. The results suggest that the optimal time of milk sample decontamination is 15 min.

[Analysis for clinical effect of a rinse containing cetylpyridinium chloride in treatment of gingivitis and periodontitis]

OBJECTIVE

To investigate the clinical effect of a 0.1% cetylpyridinium chloride(CPC) rinse on the treatment of gingivitis and periodontitis.

METHODS

A multicenter, randomized, parallel group trial was conducted. The eligible patients were divided randomly into two groups. Subjects were assessed at the beginning and the end of a two-week period during which they rinsed with 0.1% CPC or complex hibitane in addition to their usual oral hygiene procedures. The variation of PLI, SBI, GI, PD, pain, halitosis and adverse effects were observed before and after investigation.

RESULTS

After 14 days of treatment, in the CPC group, the decreasing rate of PLI was 63.0%, the effective rate for gingivitis and periodontitis were 83.3%, 36.7% respectively, while those periodontal indices of control group were 49.5%, 50% and 16.7%. After statistical analysis, the CPC group had significantly higher effective rates on gingivitis than the hibitane group (P < 0.01), at the same time, the effective rate was significantly different between two groups on periodontitis (P < 0.05).

CONCLUSION

The use of 0.1% CPC rinse is effective in treating periodontal diseases.

Inhibition of orally produced volatile sulfur compounds by zinc, chlorhexidine or cetylpyridinium chloride--effect of concentration

Zinc ions, chlorhexidine (CHX) and cetylpyridinium chloride (CPC) are all known to inhibit production of volatile sulfur compounds (VSCs). The objective was to examine the anti-VSC dose-response effects of each of the above agents. Oral malodor was induced in 13 test subjects using the cysteine challenge method. The oral VSC response to rinses with 6 mm l-cysteine (pH 7.2) before and 1, 2 and 3 h after rinsing with zinc ions (Zn2+: 0.1, 0.3 and 1.0%), CHX and CPC (0.025 and 0.2%) was measured. Mouth air was analysed for VSC by gas chromatography (GC) according to current methodology. Zinc had a marked dose- and time-dependent anti-VSC effect. Zinc at 1% concentration had a somewhat unpleasant taste, whereas the lowest concentration was found acceptable. Chlorhexidine maintained a moderate anti-VSC effect over time. At 3 h, 0.2% CHX was the most effective agent but tasted relatively unpleasant. Cetylpyridinium at a concentration of 0.2% was only marginally more effective than 0.025% CHX over the 3 h, while 0.025% CPC had no better anti-VSC effect than water at both 2 h and 3 h. It was concluded that the three test agents demonstrated different anti-VSC kinetics. Although Zn had the best anti-VSC effect at 1 h, 0.2% CHX was at least as effective as 1% Zn at 3 h, most likely as a result of its unique substantivity.

Design and characterization of mucoadhesive buccal patches containing cetylpyridinium chloride

Mucoadhesive patches for delivery of cetylpyridinium chloride (CPC) were prepared using polyvinyl alcohol (PVA), hydroxyethyl cellulose (HEC) and chitosan. Swelling and bioadhesive characteristics were determined for both plain and medicated patches. The results showed a remarkable increase in radial swelling (S(D)) after addition of the water-soluble drug (CPC) to the plain formulae. A decrease in the residence time was observed for PVA and chitosan-containing formulae. Higher drug release was obtained from PVA patches compared to HEC ones, while both are non-ionic polymers. A considerable drop in release was observed for chitosan formulae after the addition of water-soluble additives, polyvinyl pyrrolidone (PVP) and gelatin. Ageing was done on PVA formulae; the results showed there was no influence on the chemical stability of CPC, as reflected from the drug content data. Physical characteristics of the studied patches showed an increase in the residence time with storage accompanied with a decrease in drug release. This may be due to changes in the crystal habit of the drug as well as to slight agglomeration of the polymer particles.

Determination of cetylpyridinium chloride and tetracaine hydrochloride in buccal tablets by RP-HPLC

The HPLC method for simultaneous determination of cetylpyridinium chloride (CPC), tetracaine hydrochloride (TTC) in Xipiluan buccal tablets was developed and validated. The HPLC method was performed on a CN column (150 x 4.6 mm i.d., 5 microm particle size); the mobile phase was methanol-tetramethylammonium hydroxide (20 mM)-potassium dihydrogen phosphate (3 mM) (90:10:3, v/v/v) (pH* 5.0), pumped at a flow rate 1.5 ml min(-1). The UV detector was set at 230 nm. The retention time for CPC and TTC was 3.52 and 3.10 min, respectively. Calibration curves were linear (r=0.9999, n=6) in the range of 5-2000 microg ml(-1) for CPC and 1-500 microg ml(-1) for TTC. Limit of detection and quantitation for CPC was 0.033 and 0.11 microg ml(-1), for TTC were 0.0056 and 0.019 microg ml(-1). The R.S.D. of repeatability and intermediate precision for CPC and TTC were less than 2.0%.

Impact of brief exposure to balanced salts solution or cetylpyridinium chloride on the surface appearance of the rabbit corneal epithelium--a scanning electron microscopy study

PURPOSE

To examine the surface of pre-corneal mucous layer by scanning electron microscopy (SEM) with the view to assessing whether it was an amorphous, fibrous or porous structure.

METHODS

Healthy female albino rabbits (2 kg) were euthanised at 15.00 h and the corneal surface immediately fixed with buffered glutaraldehyde fixative pH 7.2 to 7.4 at 35 degrees C, carefully rinsed with balanced salts solution (BSS) and then fixed, or treated with the same fixative containing 0.05 to 0.25% w/v cetylpyridinium chloride (CPC). The corneas were critical point dried and gold-palladium coated, prior to examination at 1000x or 15000x magnification.

RESULTS

Buffered glutaraldehyde fixation resulted in an SEM image of polygonal cells, with very contrasting electron reflexes (light, medium and dark) and distinct cell surface microplicae and large crater-like features (average diameter 2.8 +/- 0.9 microm). Along the cell-cell borders was a distinct line (referred to as "caulking"), perhaps composed of mucous. Rinsing of the corneal surface with BSS just before fixation reduced the cell contrast, the surface was then covered with very short strands or small clumps of presumed mucus, the cell-cell border features were changed, but the crater-like features were largely unchanged (average diameter 2.5 +/- 0.7 microm). Fixation in the presence of 0.05% or 0.1% CPC resulted in the appearance of very short fine strands and occasional coarse mucous strands or even small plaques of mucous on the cell surfaces. The microplicae and craters were still often evident. Fixation with 0.2 or 0.25% CPC however yielded a surface with a uniform grey reflex that included numerous ultramicroscopic debris particles (average diameter of 72 nm) and was punctuated by numerous pores. No microplicae or craters were evident. The average pore diameter was 70 nm, their density averaged 59/5 microm(2), but a radial distribution analysis indicated no substantial pattern.

CONCLUSIONS

The pre-corneal mucous layer can be dispersed, by careful rinsing with a divalent cation containing solution, into small fibrils or clumps, but the cell surface craters are unaffected. After precipitation with a low concentrations of a polycation, some coarse fibrils are also formed. The use of high concentrations of a polycation in the fixative transforms the more superficial aspects of the pre-corneal mucous layer into a pore-like gel. The crater-like features therefore do not appear to be mucous, but the pore-like structure may be indicative of the organisation of the mucous layer on the surface of the living eye.

Clinical effects of a new mouthrinse containing chlorhexidine, cetylpyridinium chloride and zinc-lactate on oral halitosis. A dual-center, double-blind placebo-controlled study

OBJECTIVES

The aim of this double-blind, parallel study was to test the clinical efficacy of a newly developed mouthrinse in the treatment of oral halitosis in patients without periodontitis.

MATERIAL AND METHODS

Forty volunteers, recruited in two centers, participated in this study. Patients were selected on the basis of (1) halitosis of oral origin, (2) full-mouth organoleptic score>1, using an arbitrary 0-5 scale, (3) level of volatile sulfur compounds (VSC)>170 parts per billion (ppb) and (4) Winkel tongue coating index (WTCI)>4 (0-12). Intervention included gargling with a mouthrinse containing chlorhexidine (0.05%), cetylpyridinium chloride (0.05%) and zinc-lactate (0.14%) or with a placebo mouthrinse without active ingredients. At days 0 and 14 clinical variables were assessed in order of performance: (1) organoleptic assessments, (2) levels of VSC, and (3) WTCI.

RESULTS

Treatment with the active mouthrinse resulted in a significant mean reduction in the organoleptic score from 2.8 to 1.5 (p<0.005). In the placebo group, no significant reduction in the mean organoleptic score occurred. Consequently, this resulted, after 2 weeks, in a greater change of the organoleptic scores in the test group in comparison to the placebo group (p<0.005). The mean VSC scores were reduced from 292 to 172 ppb in the test group (p<0.005), whereas no reduction was observed in the placebo group. At the 2-week examination, the mean change of the VSC scores in the test group was significantly greater than the mean change in the placebo group (p<0.005). Neither in the test nor in the placebo group a significant reduction in tongue coating was observed.

CONCLUSIONS

In conclusion, the tested mouthrinse is effective in the treatment of oral halitosis.

Inhibitory effects on selected oral bacteria of antibacterial agents incorporated in a glass ionomer cement

The objectives of the study were to investigate the antimicrobial efficacy, over time, of combining antibacterial agents with a glass ionomer cement (GIC). This was assessed using an agar diffusion test. Chlorhexidine hydrochloride, cetylpyridinium chloride, cetrimide and benzalkonium chloride were added to Fuji IX GIC at 0, 1, 2 and 4% w/w. Antibacterial-GIC specimens were placed onto agar plates inoculated with one of six bacterial species (Streptococcis, Lactobacillus, and Actinomyces, two each) and the area of inhibition calculated after 24 h incubation. The experiment was repeated weekly and at week 11 the surface of the specimen was abraded prior to replacing on inoculated agar plates. Control specimens of the GIC produced no bacterial inhibition. The antibacterial-GIC combination specimens showed significant inhibition which decreased at different rates over the test period. Resurfacing of the specimens showed a dramatic increase of antibacterial action similar to levels produced on week 1. CT-GIC showed the greatest (p < 0.005) inhibitory effect throughout the experimental period for 4 out of 6 test bacteria. The addition of antibacterial agents to Fuji IX creates a GIC material with significant antimicrobial action in vitro which is dependent on concentration and type of antibacterial agent, and appears to be associated primarily with a release of the antibacterial from the surface layer of the specimen.

Effect of toothpaste on the plaque inhibitory properties of a cetylpyridinium chloride mouth rinse

BACKGROUND AND AIMS

Cetylpyridinium chloride (CPC) mouth rinses have moderate plaque inhibitory activity when used alone but rarely have shown adjunctive benefits to tooth brushing with toothpaste. Several explanations for this apparent anomaly can be proferred, including loss of antiseptic activity due to interactions with toothpaste ingredients. The aim of this study was to measure the effect of toothpaste on the plaque inhibitory properties of a CPC mouth rinse using paired rinses of CPC, toothpaste slurry (TP) and water (W).

METHODS

The study was a single blind, randomised, seven-treatment, cross over design balanced for residual effects, involving 21 healthy, dentate subjects. The paired rinses were: W-CPC, CPC-W, TP-CPC, CPC-TP, W-TP, TP-W and W-W. Rinsing with solutions or slurries was done for 60 s twice per day. On day 1, subjects were rendered plaque free, suspended tooth cleaning and commenced the allocated rinse regimen. On day 5, plaque was scored by index. A 2(1/2) day wash out of normal oral hygiene was allowed between each regimen.

RESULTS

The order from lowest to highest plaque scores was as follows: W-CPC = CPC-W < CPC-TP < TP-CPC < or = W-TP < TP-W < W-W. Several differences in pairs of treatments were statistically significant, the most relevant of which were significantly less plaque with W-CPC compared to TP-CPC, TP-W and W-TP, and significantly more plaque with W-W compared to all other regimens except TP-W.

CONCLUSIONS

Toothpaste, whilst possessing some plaque inhibitory activity, when used immediately before a CPC mouth rinse adversely affected the plaque inhibitory action of this antiseptic. This in part may explain the reported lack of adjunctive benefits of CPC rinses to normal oral hygiene practices and supports the suggestion, made for chlorhexidine rinses, that their use should follow toothpaste by at least 60 min.

A method to compare four mouthrinses: time to gingivitis level as the primary outcome variable

BACKGROUND AND AIM

The experimental gingivitis model is a well-established method in comparing the chemical antiplaque activity of agents and products. The aim of the present study was to use time in order to achieve an exit level of bleeding on probing (BOP) as the primary outcome variable.

METHODS

The study was a single blind, randomised four treatment parallel group design employing 76 healthy volunteers. The cohort was accepted into the study proper if they achieved a level of </= 25% BOP after a 5-week pre-study oral hygiene phase. At baseline, 1, 2, 3, 4, 5 weeks BOP, modified gingival index (MGI) and plaque index scores were obtained from each subject. After baseline, oral hygiene was suspended and subjects rinsed twice daily with one of the test rinses, namely: 1 0.05% cetylpyridinium chloride 2 Control fluoride 3 0.2% chlorhexidine 4 0.3% triclosan Subjects were removed from the study when they achieved >/= 50% BOP. Using the baseline and exit BOP, MGI and plaque, a deterioration rate for each parameter was derived and used as the unit of analysis.

RESULTS

There were highly significant treatment differences for all three parameters. Paired analyses revealed chlorhexidine was highly significantly more effective than the other rinses for all three parameters. CPC and triclosan were not different from the control for BOP, but CPC was significantly different from the control for MGI and plaque, and triclosan was different from the control for plaque. There were no differences between the CPC and triclosan rinses.

CONCLUSIONS

The method achieved the expected result of differentiating between the chlorhexidine and the other rinses. Some modification of the method, primarily to group sizes, should improve specificity. The method has the considerable volunteer appeal of early exit, particularly when allocated to control or low activity treatments for plaque.

Buccoadhesive erodible disk for treatment of oro-dental infections: design and characterisation

Buccoadhesive erodible disks of cetylpyridinium chloride were prepared using different bioadhesive polymers along with excipients like mannitol. The purpose of designing the erodible disk was to obviate the need for removal of exhausted device. The optimized disk containing 5.0 mg of cetylpyridinium chloride, 2.0 mg of magnesium stearate and 6.0 mg of mannitol along with sodium carboxy methyl cellulose DVP and hydroxypropylmethylcellulose K4M in the ratio of 1:3 was found to release the drug for a period of over 6.0 h without getting dislodged. Maximum in vitro drug release was found to be 94.78% in 6.0-h study. In situ release characteristics were evaluated using a 'flow-through assembly', which simulated the conditions of the human buccal cavity. The drug concentrations in the in situ samples were found to be above minimum inhibitory concentration (MIC) of the drug. The bioadhesive performance and the surface pH of the disks were satisfactory. Cetylpyridinium chloride disks were tested against microorganisms commonly found in oro-dental infections namely Candida albicans, Staphylococcus aureus, Escherichia coli and Streptococcus mutans. The disk as well as the in situ samples showed inhibition of growth of microorganisms. Approval was taken from Jamia Hamdard Review Board (Ethical Board) to perform in vivo studies in healthy human volunteers. In vivo evaluation of buccoadhesive disks revealed adequate comfort, taste, and non-irritation and none of the volunteers reported severe dry mouth/severe salivation or heaviness at the place of attachment. Salivary concentrations were maintained above MIC for 8.0 h. Correlation was found between the drug concentration in situ and concentration of drug in saliva collected in healthy human volunteers. The correlation was found to be positive with a correlation coefficient of 0.9596. It was found to be statistically significant at 5% confidence level (P<0.05).

Effect of different chlorhexidine formulations in mouthrinses on de novo plaque formation

BACKGROUND

Chlorhexidine (CHX) 0.2% solution, still the golden standard as mouthrinse for the prevention of plaque formation and development of gingivitis, has some limited side-effects such as extrinsic tooth staining, poor taste, taste disturbance, sensitivity changes in tongue, pain, and the content of alcohol. These side effects led to the search of new formulations.

METHODS

In this double-blind, randomised, cross-over study, 16 young dental students with a healthy periodontium, abolished all means of mechanical plaque control during 4 experimental periods of 11 days (separated from each other by a washout period of 3 weeks). During each experimental period, they rinsed 2x daily with one of the following mouthrinses in a randomised order: CHX 0.2% + alcohol (Corsodyl), CHX 0.12% + alcohol (Perio.Aid), CHX 0.12% + sodium fluoride 0.05% (Cariax Gingival) and CHX 0.12% + CPC 0.05% (Perio.Aid, new formulation). After 7 and 11 days of undisturbed plaque formation, clinical parameters were recorded, questionnaires completed and plaque samples (supragingivally and saliva) collected.

RESULTS

The CHX 0.12% + alcohol and the CHX 0.12% + CPC 0.05% formulations were as efficient as the CHX 0.2% mouthrinse in retarding de novo plaque formation (proven by clinical observations as well as by anaerobic and aerobic culture data), and always superior (p<0.001) to the CHX 0.12% + sodium fluoride 0.05% solution. The subjective ratings were in favour of the new CHX formulation when compared with the other CHX formulations, especially for taste (p<0.05).

CONCLUSIONS

The results of this study demonstrated the potential of a new CHX 0.12% + CPC 0.05% non-alcoholic formulation as an effective anti-plaque and anti-inflammatory agent with reduced unpleasant subjective side-effects.

Fractional inhibitory concentration index of combinations of antibacterial agents against cariogenic organisms

OBJECTIVES

To examine the inhibitory effects between paired combinations of four antibacterial agents that have been investigated in dentistry against six bacteria associated with dentinal caries.

METHODS

The antibacterial agents tested were: chlorhexidine dihydrochloride, benzalkonium chloride, cetrimide and cetylpyridinium chloride. Two organisms each belonging to Streptococcus, Lactobacillus and Actinomyces species were evaluated against these agents. A checkerboard microtitration method was used to determine the minimum inhibitory concentration and fractionary inhibitory concentration (FIC) and summation operator FIC index of the paired combinations of antibacterial agents against the six species of bacteria. Appropriate controls were included. The summation operator FIC index was then used to determine if synergy, antagonism, or indifference occurred as a result of interactions between the antibacterial agents and the test organisms.

RESULTS

The data from a total of 295 test results were evaluated. Using summation operator FIC values for synergy as < or = 0.5 and antagonism as > 4.0 as recommended by The American Society for Microbiology, no significant synergistic or antagonistic interactions were observed between the paired antibacterial agents when tested against selected organisms. However, a tendency for an additive antibacterial effect was observed with approximately a third of the test results. Nonetheless, no combination of antibacterial agents appeared to be superior to any other.

CONCLUSIONS

According to these in vitro results, there appears to be no beneficial effect of combining the antibacterial agents against the individual cariogenic micro-organisms selected. However, it may be beneficial to use combined antibacterial agents that have a broader range of activity against an ecosystem of bacteria than using individual agents.

Antibacterial activities and release kinetics of a newly developed recoverable controlled agent-release system

We attempted to develop a resin with a recoverable antibacterial activity based on the desorption/adsorption of a cationic bactericide by the ion-exchange mechanism. The aims of this study were to investigate the release kinetics of the agent and the antibacterial activity of this newly designed resin system. An experimental resin was prepared by the addition of methacrylic acid as a cation-exchanger and a cationic antibacterial agent, cetylpyridinium chloride (CPC), to triethyleneglycol dimethacrylate. The amount of CPC desorbed from the experimental resin into buffer solutions at pH 4-8 was measured. The adsorption of CPC to control resin and re-adsorption of CPC to the experimental resin, which had once desorbed the agent, were also determined. The antibacterial activity of experimental resin against Streptococcus mutans was evaluated, and the relationship between bacterial acid production and antibacterial effect was assessed. The experimental resin desorbed CPC at pH < or = 6, and the amount of agent desorbed increased with increasing acidity. The control resin adsorbed CPC when immersed in CPC aqueous solution at a rate determined by the concentration of the agent and immersion time. The experimental resin, once desorbed CPC, could re-adsorb the bactericide by being exposed to a solution of the agent. Less plaque formed on the experimental resin, and the growth and survival of S. mutans was inhibited in the condition in which acid was produced. These results demonstrate that the resin system proposed was able to desorb and re-adsorb the cationic bactericide by an ion-exchange mechanism and could show an inhibitory effect on S. mutans growth and plaque formation.

In vitro action of a combination of selected antimicrobial agents and chondroitin sulfate

Chondroitin sulfate (CS), a highly anionic polymer and the most predominant sulfated glycosaminoglycan in connective tissues, was investigated regarding to its interaction with cationic disinfectants, which are used as antiinfectives in humans. Combinations of cetylpyridiniumchloride (CPC), chlorhexidine (CHex), and polyhexamethylene biguanide (PHMB) with CS, respectively, were prepared and the resulting microbicidal activity of the mixtures was tested in the quantitative suspension test without organic matter. Polyvidone-iodine and Ringer's solution were used as controls. Even precipitated, the resulting test combinations behave differently against Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. CPC/CS demonstrated only microbicidal activity against Gram-positive bacteria, and CHex/CS was more active against Gram-negative bacteria and C. albicans. PHMB/CS, especially in combination with CS-A, only revealed an antimicrobial effect against P. aeruginosa after 60 min action. The interaction of cationic disinfectants with CS showed depending on the investigated microorganism a more or less controlled sustained release manner of the microbicidal agent from the precipitated complex, with the only exception of PHMB in combination with CS-C, which is completely neutralized. Polyvidone-iodine and Ringer's solution were not affected by CS.

The effects of a potassium citrate, cetylpyridinium chloride, sodium fluoride mouthrinse on dentine hypersensitivity, plaque and gingivitis. A placebo-controlled study

Home-use studies on dentine hypersensitivity have most commonly involved toothpastes and rarely have mouthrinses been employed. Potassium and/or fluoride toothpastes have been shown effective in the treatment of dentine hypersensitivity. The aim of this study was to evaluate the effectiveness of a total formulation, containing potassium citrate, sodium fluoride, cetylpyridinium chloride mouthrinse compared to the base rinse minus actives in the reduction of dentine hypersensitivity. The study was a randomised placebo controlled, double blind parallel design. At a screening visit, 90 adult subjects were recruited who were suffering from dentine hypersensitivity from at least 1 tooth responding to tactile stimulation (45gm pressure) and had at least 2 teeth responding to evaporative stimulation (air blast). During a washout period of 28 days and throughout the 56-day study period, subjects used a soft filament toothbrush and standard fluoride toothpaste. At baseline (day 1), threshold sensitivities to incremental tactile (10 g to 70 g) and evaporative stimuli were determined. Gingival health was assessed by recording bleeding on probing at 25 g pressure at mesiobuccal and lingual sites. Plaque scores from buccal and lingual surfaces of disclosed teeth were also measured. Subjects then used the prescribed rinse, 10 ml for at least 30 s after brushing 2x per day returning on days 28 and 56 for rescoring of sensitivity, gingivitis and plaque. Data from 88 subjects were used with the intent to treat analyses and 83 in the completely evaluable analyses. Groups were well balanced for demographic data and product returns suggested good compliance. Both groups showed highly significant improvements in tooth sensitivity. The pattern was for greater improvement in the test compared to the control group (statistically significant for the plaque score), whereas bleeding scores, already low, showed no change in either group. By definition, the placebo rinse could not have exerted any therapeutic action; the study therefore provides clear direct evidence as to the magnitude (30%-40%) of the little studied, but assumed, placebo response in dentine hypersensitivity trials.

In vitro antifungal properties of mouthrinses containing antimicrobial agents

The purpose of this study was to investigate the in vitro antifungal properties of seven commercial mouthrinses containing antimicrobial agents. These included cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), hexetidine (HEX), sanguinarine (SNG), and triclosan (TRN). The minimum fungicidal concentration (MFC) against six species of yeasts was determined by a broth macrodilution method. The kill-time of mouthrinses at half the concentration of the commercial formulations was also determined. MFCs were achieved with each mouthrinse, except the SNG-containing mouthrinse, against all the organisms being tested. However, the CPC-containing mouthrinse appeared more active than the other products (P < 0.001). There were no significant differences in MFC values among CHX mouthrinse products, once adjusted for initial concentration differences (P = 0.1). Kill-times of mouthrinses containing either CHX or CPC were less than or equal to 180 seconds with all the species of yeasts, and no significant differences were found among these products (P = 0.18). On the other hand, mouthrinses containing either TRN or HEX did not show a lethal effect on Candida albicans, Candida parapsilosis, or Candida guilliermondii. No kill-times were achieved with the SNG-containing mouthrinse. These results suggest that mouthrinses containing antimicrobial agents might represent an appropriate alternative to conventional antifungal drugs in the management of oral candidiasis. However, the effectiveness of antimicrobial mouthrinses as antifungal agents needs to be evaluated in further clinical trials.

Buccoadhesive tablets for the slow delivery of cetylpyridinium chloride: design and in vitro/in vivo analysis

A buccoadhesive slow-release system constituted by a monolayer tablet was developed for the administration of cetylpyridinium chloride (CPC). Tablet composition was based on a mixture of a bioadhesive polymer with conventional excipients. Three different polymers (Methocel K4M, Noveon AA1, Carbopol 974P) in three different concentrations (10%, 20%, 30%) were used. The release profile and the adhesion properties of nine formulations were evaluated in vitro. Based on these results three formulations containing 10% w/w of the tested polymers were chosen to assess, with preliminary in vivo studies, the compliance and the residence time in the month of the systems. Tablets containing Noveon AA1 showed the best performances.

Excipient interaction with cetylpyridinium chloride activity in tablet based lozenges

PURPOSE

The purpose of the investigation was to determine the effect of tablet excipients on the activity of cetylpyridinium chloride (CPC) and the relative interaction between excipients and CPC.

METHODS

An analytical assay was developed to evaluate the interaction between CPC and the excipients. In vivo activity was investigated using six volunteers by determining the reduction in colony forming units recoverable from the oropharynx after sucking each proprietary lozenge separately on different days. In vitro determinations investigated the relative antimicrobial activity of aqueous solutions of the lozenges and, the effect of pH and tablet base excipients on that activity against Staphylococcus aureus, Streptococcus pyogenes and Candida albicans.

RESULTS

Both in vivo and in vitro results showed that the tablet based lozenges had markedly reduced antimicrobial activities compared with previous results with a candy based lozenge (in vivo and in vitro) or the same concentration of aqueous CPC (in vitro). Magnesium stearate suspensions in CPC 250 micrograms/ml indicated that magnesium stearate adsorbed CPC and at 0.4% lozenge weight and above significantly reduced the antimicrobial activity of CPC 250 micrograms/ml.

CONCLUSIONS

The reduced activity of CPC in tablet based lozenges resulted from a decreased availability of CPC in solution due to an adsorption of CPC on magnesium stearate. To avoid this reduction in activity tablet based lozenges containing CPC 250 micrograms/ml, or similar concentrations, plus magnesium stearate should contain not more than 0.3% w/w lozenge weight of the lubricant.

The effect of formulation on the antimicrobial activity of cetylpyridinium chloride in candy based lozenges

PURPOSE

The purpose of this investigation was to determine the influence on the antimicrobial activity of cetylpyridinium chloride of the various components of the formulation of each of six candy based lozenges.

METHODS

In vivo activity was investigated using six volunteers by determining the reduction in colony forming units recoverable from the oropharynx after sucking each lozenge separately on different days. In vitro determinations investigated the relative activity of aqueous solutions of the lozenges, the effect on activity of additional active ingredients, pH and lozenge base ingredients against separate inocula of each of the test organisms Staphylococcus aureus, Streptococcus pyogenes and Candida albicans.

RESULTS

Both in vivo and in vitro results showed that the pH of the dissolved lozenge solution was the single most influential readily adjustable formulation parameter which significantly influenced the activity of cetylpyridinium chloride activity in candy based lozenges.

CONCLUSIONS

Lozenges containing cetylpyridinium chloride as the active ingredient should be formulated at a pH greater than 5.5.

[Comparison of in vitro action of cetylpyridinium chloride containing preparations]

The fungicidal efficacy on Candida albicans of cetylpyridinium chloride (CAS 123-03-5) solution (CPC I solution, Dobendan) in various dilutions was tested with help of the quantitative suspension test and compared with CPC containing self-made preparations with or without addition of alcohol. The dilution of all test preparations caused an impairment of antimicrobial efficacy; the activity was reduced distinctly: due to a 50% dilution a decrease of 2-3 ten's powers was observed. The reduction of efficacy of the self-made preparation was less pronounced. The addition of 1% albumin as well impaired the fungicidal activity of all test preparations. CPC + alcohol revealed the most pronounced fungicidal efficacy; no differences were seen between CPC (without alcohol) and CPC I solution.

Efficacy on supragingival plaque control of cetylpyridinium chloride in a slow-release dosage form

To evaluate the relative efficacy of a non-degradable osmotic slow-release dosage form containing 6.6 mg cetylpyridinium chloride (MOTS [Mucosal Oral Therapeutic System] CPC) to inhibit new plaque formation and gingivitis, a single-blind, randomised, parallel group pilot study was set up. 52 healthy volunteers were assigned to receive one of the following treatments for 18 days of non-brushing: holding 1 MOTS CPC 2 x daily for 2 h intra-orally, or rinsing 30 s with 15 ml Peridex 2 x daily, or dissolve Cepacol (each 1.6 mg CPC) lozenges 2 x daily unsupervised. Before the test period, the subjects received a thorough tooth cleaning followed by tooth polishing 1 x a week for 3 weeks to achieve clinical gingival health. After the start of therapy, the subjects were examined at day 4, 7 (+/- 2), 14 (+/- 2) and 18 (2 +/-). Relative efficacy was assessed by the modified Navy plaque index, the Quigley and Hein index, the planimetric plaque index, as well as the papillary marginal gingival index. There was an increase in both plaque formation and gingivitis over the 18 +/- 2 day period of nonbrushing for all subjects in the study. Peridex was the most effective in inhibiting plaque and gingivitis formation over that period of time. There was no difference between MOTS CPC and Cepacol at any time point in plaque accumulation and gingivitis intensity. Peridex was considered more convenient than MOTS CPC. Cepacol resulted in more staining at 18 days than MOTS CPC and Peridex.

Efficacy of mouthrinses in inhibiting the development of supragingival plaque over a 4-day period of no oral hygiene

This study was a first stage evaluation of the plaque inhibitory properties of an experimental cetylpyridinium chloride (CPC)/essential oil mouthrinse. The study was a formulation, not ingredient, evaluation and comparisons were made with established mouthrinse products. The 5 rinses tested were: the experimental formulation; a triclosan/copolymer prebrushing mouthrinse; two negative control rinses, which differed only in color; and as a positive control, a 0.2% chlorhexidine mouthrinse. The study used a 5 cell, 4-day plaque regrowth, double-blind crossover design in which 15 subjects participated. Allocation of mouthrinse sequences was accomplished using 3 replicates of a 5 x 5 Latin square, incorporating balance for carryover. On Day 1, subjects received a scaling and polishing to reduce plaque, ceased toothcleaning, and commenced rinsing twice daily, under supervision, with the randomly assigned rinse. Rinsing time for the experimental and one negative control rinse was 30 seconds and for the other rinses was 60 seconds. On Day 5, plaque was scored by both index and area. Differences in plaque regrowth between the rinse groups were highly significant. The order of efficacy from the most effective was: chlorhexidine rinse (positive control); experimental CPC/essential oil rinse; triclosan/copolymer rinse; and the negative control rinses. From the calculated confidence intervals each rinse differed significantly from each other rinse, except for the two negative control rinses which were comparable to each other. Proportionately, the CPC/essential oil rinse was positioned 30 to 50% between the triclosan/copolymer rinse and the chlorhexidine (positive control). These findings suggest that the CPC/phenolic rinse would seem worthy of further evaluation for adjunctive benefits to oral hygiene.

A comparison of cetylpyridinium chloride, triclosan and chlorhexidine mouthrinse formulations for effects on plaque regrowth

A relatively small number of agents are used in mouthrinse products, although the possible variability in the final formulations is enormous. The aim of this study was to compare equal concentrations of 3 antimicrobial agents, in simple formulations, for plaque inhibition. This 4-day plaque regrowth study was a 5-cell, randomised, double blind cross-over design, involving 20 healthy human volunteers. The mouthrinse formulations were aqueous 0.05% solutions of cetylpyridinium chloride (CPC), chlorhexidine and triclosan, together with a 0.1% CPC and a minus active control rinse. On Day 1, from a zero plaque baseline, volunteers ceased normal oral hygiene and rinsed 2x daily for 1 min. with 10-ml volumes of the allocated rinses. On Day 5, plaque was scored by index and area. All rinses produced lower mean plaque values compared to control, but unlike the CPC and chlorhexidine rinses, the differences with triclosan did not always reach significance. The CPC and chlorhexidine rinses were always significantly more effective than the triclosan rinse. The greatest plaque inhibition was with 0.1% CPC although rarely significantly greater than the 0.05% CPC and chlorhexidine rinses which were similar in efficacy. The results indicate that further studies on lower concentration chlorhexidine solutions are warranted.

A double-blind, vehicle-controlled study of the safety and efficacy of Fungoid Tincture in patients with distal subungual onychomycosis of the toes

Onychomycosis is one of the most common causes of nail disease and one of the hardest to treat among fungal infections. A double-blind, vehicle-controlled study has been conducted to evaluate the safety and efficacy of Fungoid Tincture (Pedinol Pharmacal, Inc), for the treatment of fungal infection of the toenails. Ten patients with distal subungual onychomycosis were treated for twelve months with topical Fungoid Tincture. Another ten patients with the same ailment were treated with the vehicle alone. Once a month, clinical and global evaluation of the target nail was done, in addition to trimming and debridement of the nails. After twelve months of treatment, 90 percent of patients applying Fungoid Tincture showed negative results on culture. There were minimal adverse effects.

Effects of subinhibitory concentrations of chemical agents on hydrophobicity and in vitro adherence of Streptococcus mutans and Streptococcus sanguis

The aim of this investigation was to determine whether sublethal concentrations of chlorhexidine (Cx), hexetidine (Hx), cetylpyridinium chloride (Cc), sodium dodecyl sulfate (SDS), sanguinarine (Sg), sodium fluoride (NaF), and ammonium fluoride (NH4F) could affect hydrophobicity and adhesion of Streptococcus sanguis and Streptococcus mutans to saliva-coated hydroxyapatite (S-HA). Determination of the minimum inhibitory concentrations (MICs) showed that both species were susceptible to all agents tested. Growth in the presence of sub-MIC concentrations of Cx, SDS, Cc, NaF, or NH4F did not change significantly the hydrophobicity of S. sanguis cells when compared to the control which lacked any agent. However, growth in the presence of Hx or Sg resulted in a significant reduction in their hydrophobicity. Sub-MIC levels of SDS or Sg in the growth medium resulted in S. mutans cells with increased affinity for hexadecane compared with the control. The adherence of S. sanguis was changed significantly only by Hx or Sg, resulting in less cells adhering to S-HA. However, S. mutans cells previously incubated with NaF, NH4F, or Sg showed a higher adherence to S-HA than the control. The mechanisms of interference with adherence are at present not completely understood. Thus, antimicrobial agents at sub-MIC concentrations can interfere selectively with hydrophobicity and/or adhesion of oral streptococci.

Inhibition of plaque formation by local application of a degradable controlled release system containing cetylpyridinium chloride

The effect of a degradable controlled release system containing cetylpyridinium chloride (CPC) on plaque accumulation and gingivitis was evaluated when applied on the anterior teeth of volunteers (16-17 years) over 4 weeks. At baseline, plaque index (PI) and gingival index (GI) of the Ramfjord teeth were measured in the experimental and placebo groups, including 23 and 21 participants respectively. Following scaling and root planning, the participants were instructed to brush, using one brush stroke, the film-forming solution on the buccal surface of the maxillary and mandibular incisors, 1 x a day before bedtime. The applied active solution contained 9 mg of CPC (approximately 80 mg of 11% CPC solution), while the placebo solution was identical in formation, but without the active agent. After 4 weeks, in the CPC-applied group, the recorded PI scores were 0.52 (+/- 0.56) in the anterior area and 1.31 (+/- 0.80) in the posterior area, whereas the corresponding areas in the placebo group reached 1.25 (+/- 0.74) and 1.51 (+/- 1.00), respectively. The PI = 0 frequency in the buccal anterior surfaces after 4 weeks was 54.6% (+/- 38.7%) in the experimental group as compared with 21.9% (+/- 29.0%) in the placebo group (p = 0.005). In contrast to the anterior teeth, there was no significant difference between groups with respect to the PI scores in the non-applied posterior teeth. It may be postulated that the impressive 58% inhibition of plaque accumulation at the site of application is the result of an increase of the substantivity of the CPC due to its incorporation in the film-forming degradable controlled release system.

Open-label study of the safety and efficacy of Fungoid tincture in patients with distal subungual onychomycosis of the toes

Onychomycosis is the most frequent cause of nail diseases. An open-label study has been conducted to evaluate the safety and efficacy of Fungoid Tincture, a topical antifungal agent approved by the Food and Drug Administration for the treatment of onychomycosis of the toes. Ten patients with culture-proven distal subungual onychomycosis were treated twice daily for twelve months with topical Fungoid Tincture. Another ten patients with the same condition were treated with the vehicle alone. At monthly intervals, the target nail was trimmed, the nail bed debrided, and global clinical assessment recorded. After twelve months of therapy, all patients applying Fungoid Tincture showed negative findings on fungal culture. The vehicle alone benefitted several patients, and may have antifungal activity. Adverse effects were minimal, with mild peeling occurring in seven patients and erythema noted in one.

Day-long reduction of oral malodor by a two-phase oil:water mouthrinse as compared to chlorhexidine and placebo rinses

Few scientific investigations have addressed the ability of mouthrinses to reduce oral malodor for periods longer than 3 hours. In the present report, we have employed simple, recently described techniques to assess the day-long reduction in oral malodor of a novel 2-phase oil:water mouthrinse (TPM), as compared to a corresponding placebo rinse, and to a commercial 0.2% chlorhexidine mouthrinse. Sixty dental students were divided randomly into 3 groups, and instructed to use one of the rinses prior to bedtime and the following morning. Measurements carried out in the late afternoon, about 8 to 10 hours following rinsing, were compared with baseline measurements carried out in the late afternoon of the previous day. Volatile sulphide levels were measured using a portable industrial sulphide monitor. Microbial levels were estimated using a simple rinsing technique employing sterilized milk. These quantitative techniques were corroborated by organoleptic (hedonic) ratings of a single odor judge. Both TPM and chlorhexidine brought about significant decreases in volatile sulphides (P less than 0.05) as compared to the placebo group. These results were corroborated by the organoleptic data. Similarly, both chlorhexidine and TPM were highly effective in reducing microbial levels as measured by the rinsing technique, in comparison to the placebo group. Chlorhexidine appeared to be more effective than TPM in all measurement categories, although only in the case of microbial activity was there a significant (P less than 0.05) difference between the two groups.

Acute inhalation toxicity of cetylpyridinium chloride

Cetylpyridinium chloride (CPC) is a quaternary ammonium salt and cationic surfactant. It has been used as a biocide in personal hygiene products and a charge control additive in some reprographic toners. CPC is orally toxic to rats, mice and rabbits and can cause severe eye irritation. Acute inhalation toxicity studies of CPC and other quaternary ammonium salts have not, however, been reported. Groups of five rats per sex were exposed to aerosols containing 0 (control), 0.05, 0.07, 0.13 and 0.29 mg CPC/litre for 4 hr and observed for toxicity and ocular effects for 14 days thereafter. All animals were subjected to autopsy and the eyes were examined microscopically. The LC50 (sexes combined) of CPC was 0.09 mg/litre with upper and lower 95% confidence limits of 0.13 and 0.07 mg/litre, respectively. Clinical signs of toxicity included weight loss, nasal discharge, chromodacryorrhoea, respiratory difficulty and eye irritation, and all these non-lethal effects were reversible. Acute inflammation of the cornea, iris and/or aqueous humour were found in one, seven and four of 10 rats exposed to 0.07, 0.13 and 0.29 mg CPC/litre, respectively. Corneal epithelial hyalinization, without evidence of ongoing inflammation, was found in three additional rats among the 10 exposed to 0.29 mg CPC/litre.

The effects of a cetylpyridinium chloride prebrushing rinse as an adjunct to oral hygiene and gingival health

A NUMBER OF MOUTHWASH PRODUCTS containing cetylpyridinium chloride (CPC) are available. Data for individual products are limited, although overall the antiseptic has been shown to reduce plaque. Results for gingivitis reductions by CPC have been equivocal. This study was an active/placebo parallel group design to evaluate the use of a CPC mouthrinse as an adjunct to oral hygiene when used before toothbrushing. Plaque and gingivitis scores were recorded at baseline and after 6 weeks, following twice daily use of the active or placebo prebrushing rinses. Plaque and gingivitis were significantly reduced at 6 weeks in both groups with no significant treatment differences between the active and placebo formulations. Whether the order of rinsing to toothbrushing influenced these findings cannot be determined. However, the results further question the adjunctive benefits of CPC rinses to gingival health.

Combined effects of Zn(2+)-chlorhexidine and Zn(2+)-cetylpyridinium chloride on caries incidence in partially desalivated rats

The effects of Zn2+ combined with either chlorhexidine or cetylpyridinium chloride (CPC) on caries incidence in partially desalivated rats were investigated. Seven groups of 12 animals each received topical applications for 20 s with a saturated swab (0.2 ml) of the following aqueous solutions twice daily on weekdays (10 a.m. and 3 p.m.) and once daily during weekends (12 a.m.) for 5 wk: deionized water (placebo); 40 mM zinc acetate; 2.2 mM chlorhexidine diacetate; 4.4 mM CPC; 40 mM zinc acetate and 2.2 mM chlorhexidine diacetate; 40 mM zinc acetate and 4.4 mM CPC; and 20 mM NaF (positive control). Coronal caries was scored by the method of Keyes. All treatments except CPC alone resulted in significantly (P less than 0.05, ANOVA) less smooth-surface caries than did the placebo. NaF treatment resulted in significantly less smooth-surface caries than did Zn2+, chlorhexidine, CPC, and Zn(2+)-CPC. The inclusion of zinc ions did not significantly increase the caries-inhibitory efficacy of chlorhexidine (CH). The combination of Zn(2+)-CPC decreased smooth-surface scores significantly more than did CPC alone. Significant differences in sulcal-surface caries were not observed among the groups. Zn(2+)-CPC suppressed the Streptococcus sobrinus counts significantly more than did the separate agents. Animals treated with Zn(2+)-CH harbored the lowest populations of S. sobrinus.

Interactions of sanguinarine and zinc on oral streptococci and Actinomyces species

Sanguinaria extract, which contains benzophenanthridine alkaloids, has been used as a folk medicine for many years. Minimum inhibitory and minimum bactericidal concentrations (MIC and MBC values) for sanguinarine were determined for common and etiologically important plaque bacteria. Because the efficacy of sanguinarine is believed to be enhanced by zinc, isobolograms were assessed to determine their mode(s) of interaction. Hydrogen ion concentration influenced the inhibitory activity of both sanguinarine and zinc. For sanguinarine, at the optimum pH (6.5), MIC values were 4 or 8 micrograms/ml for Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguis, Actinomyces viscosus and Actinomyces naeslundii. MIC values were 0.125-0.50 mmol Zn/ml. MBC values ranged from 1 to 8 mmol Zn/ml at pH 5.5. Isobologram data revealed that sanguinarine and zinc interacted synergistically. Viadent oral rinse, which contained 300 micrograms sanguinaria extract/ml and 0.2% zinc chloride (14.9 mmol Zn/l), was inhibitory to all strains tested. MIC values were 1 or 2% (ml Viadent oral rinse/100 ml aqueous solution) for all strains except A. viscosus for which the MIC value was 12% (vol/vol).

[Effect of cetylpyridinium chloride on formation and metabolism of human dental plaque]

In this work, the Cepacol (cetylpyridinium chlorid) diluted 1:2, when used for mouthwashes three time a day decreased the "in situ" formation of human dental plaque, however it didn't decreased neither the plaque fermentation, nor the IEP synthesis by the plaque. When the Cepacol was used for treating the "in vitro" dental plaque in both 1:10 and 1:20 dilutions, decreased the fermentation and the IEP synthesis of the "in vitro" plaque.