Benzocaine: Review on a Drug with Unfold Potential.

Benzocaine is well-known for its role as an anesthetic agent and largely used in oral ulcers, ear pain and dental complications. Along with lidocaine and other local anesthetics, benzocaine has marked it as an anesthetic agent in surgical procedures and as Na+ channels blocker, as well. Analogues of benzocaine have been found to possess biological potentials including antibacterial, antifungal and anti-cancer. Some derivatives were found to have conspicuous action against tuberculosis. The current review focuses to explore the century-long potential of the molecule and its analogs that have appeared in the literature. Furthermore, highlighting the biological potential of benzocaine and its analogues shall open-up new dimensions of future research to design more potent analogues.

Efficacy and safety of a triple active sore throat lozenge in the treatment of patients with acute pharyngitis: Results of a multi-centre, randomised, placebo-controlled, double-blind, parallel-group trial (DoriPha).

OBJECTIVE: The aim of this multi-centre, randomised, double-blind, placebo-controlled trial was to compare the efficacy and safety of the fixed combination of 0.5 mg tyrothricin, 1.0 mg benzalkonium chloride, and 1.5 mg benzocaine (study drug marketed as Dorithricin® ) in repeat dosing for 3 days to match placebo lozenges in the treatment of acute pharyngitis in adults. METHODS: Patients (pts, aged ≥18 years) with acute pharyngitis, ie, non-streptococcal sore throat and moderate-to-severe pain (intensity NRS ≥ 7; VAS ≥ 50) were assigned to study drug (n = 160) or matching placebo (n = 161). Efficacy was assessed by investigator for 2 hours post initial dose (p.i.d.), and 3 days later (Visit 2). Primary efficacy endpoint was the complete resolution of throat pain and difficulty in swallowing at Visit 2 (3 days p.i.d.). Safety and local tolerability were also assessed. RESULTS: Seventy-two hours (p.i.d.), complete resolution of throat pain and difficulty in swallowing were achieved by 44.6% patients on study drug compared with 27.2% patients on placebo (difference 17.4% (CI [5.8%; 29.7%]; 64% improvement [GEE, P = 0.0022]). Until 2 hours p.i.d., reduction in symptoms was better with study drug (P < 0.005). Treatment satisfaction was higher with study drug (patients'/investigators' assessment (78.9%/78.9% vs 55.0%/55.6% for placebo) and was well tolerated, overall safety profile was comparable to placebo. CONCLUSION: The strength of this randomised controlled trial lies in the endpoint of complete remission after 3 days p.i.d., especially in the light of other trials addressing acute pharyngitis. The results of this study show a significant benefit of the study drug over placebo in the treatment of acute pharyngitis. Local treatment with the fixed combination (0.5 mg tyrothricin, 1.0 mg benzalkonium chloride, and 1.5 mg benzocaine) provides a rapid analgesic effect and is effective in relieving both severe throat pain as well as difficulty in swallowing associated with acute pharyngitis leading to a 64% improved complete remission within 72 hours. The triple active combination is a suitable treatment option for patients in the self-management of acute pharyngitis and sore throat. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT03323528.

Ear drops for the removal of ear wax.

BACKGROUND: Ear wax (cerumen) is a normal bodily secretion that can become a problem when it obstructs the ear canal. Symptoms attributed to wax (such as deafness and pain) are among the commonest reasons for patients to present to primary care with ear trouble.Wax is part of the ear's self-cleaning mechanism and is usually naturally expelled from the ear canal without causing problems. When this mechanism fails, wax is retained in the canal and may become impacted; interventions to encourage its removal may then be needed. Application of ear drops is one of these methods. Liquids used to remove and soften wax are of several kinds: oil-based compounds (e.g. olive or almond oil); water-based compounds (e.g. sodium bicarbonate or water itself); a combination of the above or non-water, non-oil-based solutions, such as carbamide peroxide (a hydrogen peroxide-urea compound) and glycerol. OBJECTIVES: To assess the effects of ear drops (or sprays) to remove or aid the removal of ear wax in adults and children. SEARCH METHODS: We searched the Cochrane ENT Trials Register; Cochrane Register of Studies; PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 23 March 2018. SELECTION CRITERIA: Randomised controlled trials (RCTs) in which a 'cerumenolytic' was compared with no treatment, water or saline, an alternative liquid treatment (oil or almond oil) or another 'cerumenolytic' in adults or children with obstructing or impacted ear wax. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. The primary outcomes were 1) the proportion of patients (or ears) with complete clearance of ear wax and 2) adverse effects (discomfort, irritation or pain). Secondary outcomes were: extent of wax clearance; proportion of people (or ears) with relief of symptoms due to wax; proportion of people (or ears) requiring further intervention to remove wax; success of mechanical removal of residual wax following treatment; any other adverse effects recorded and cost. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. MAIN RESULTS: We included 10 studies, with 623 participants (900 ears). Interventions included: oil-based treatments (triethanolamine polypeptide, almond oil, benzocaine, chlorobutanol), water-based treatments (docusate sodium, carbamide peroxide, phenazone, choline salicylate, urea peroxide, potassium carbonate), other active comparators (e.g. saline or water alone) and no treatment. Nine of the studies were more than 15 years old.The overall risk of bias across the 10 included studies was low or unclear. PRIMARY OUTCOME: proportion of patients (or ears) with complete clearance of ear waxSix studies (360 participants; 491 ears) contributed quantitative data and were included in our meta-analyses.Active treatment versus no treatmentOnly one study addressed this comparison. The proportion of ears with complete clearance of ear wax was higher in the active treatment group (22%) compared with the no treatment group (5%) after five days of treatment (risk ratio (RR) 4.09, 95% confidence interval (CI) 1.00 to 16.80); one study; 117 ears; NNTB = 8) (low-quality evidence).Active treatment versus water or salineWe found no evidence of a difference in the proportion of patients (or ears) with complete clearance of ear wax when the active treatment group was compared to the water or saline group (RR 1.47, 95% CI 0.79 to 2.75; three studies; 213 participants; 257 ears) (low-quality evidence). Two studies applied drops for five days, but one study only applied the drops for 15 minutes. When we excluded this study in a sensitivity analysis it did not change the result.Water or saline versus no treatmentThis comparison was only addressed in the single study cited above (active versus no treatment) and there was no evidence of a difference in the proportion of ears with complete wax clearance when comparing water or saline with no treatment after five days of treatment (RR 4.00, 95% CI 0.91 to 17.62; one study; 76 ears) (low-quality evidence).Active treatment A versus active treatment BSeveral single studies evaluated 'head-to-head' comparisons between two active treatments. We found no evidence to show that one was superior to any other.Subgroup analysis of oil-based active treatments versus non-oil based active treatmentsWe found no evidence of a difference in this outcome when oil-based treatments were compared with non-oil-based active treatments. PRIMARY OUTCOME: adverse effects: discomfort, irritation or painOnly seven studies planned to measure and did report this outcome. Only two (141 participants;176 ears) provided useable data. There was no evidence of a significant difference in the number of adverse effects between the types of ear drops in these two studies. We summarised the remaining five studies narratively. All events were mild and reported in fewer than 30 participants across the seven studies (low-quality evidence).Secondary outcomesThree studies reported 'other' adverse effects (how many studies planned to report these is unclear). The available information was limited and included occasional reports of dizziness, unpleasant smell, tinnitus and hearing loss. No significant differences between groups were reported. There were no emergencies or serious adverse effects reported in any of the 10 studies.There was very limited or no information available on our remaining secondary outcomes. AUTHORS' CONCLUSIONS: Although a number of studies aimed to evaluate whether or not one type of cerumenolytic is more effective than another, there is no high-quality evidence to allow a firm conclusion to be drawn and the answer remains uncertain.A single study suggests that applying ear drops for five days may result in a greater likelihood of complete wax clearance than no treatment at all. However, we cannot conclude whether one type of active treatment is more effective than another and there was no evidence of a difference in efficacy between oil-based and water-based active treatments.There is no evidence to show that using saline or water alone is better or worse than commercially produced cerumenolytics. Equally, there is also no evidence to show that using saline or water alone is better than no treatment.

What are pharmacists recommending for infant teething treatment?

OBJECTIVES: In 2011, the Food and Drug Administration issued a warning to avoid the use of any benzocaine-containing products for infant teething treatment owing to a risk of methemoglobinemia. Several benzocaine-containing products targeted for infant teething are currently available over the counter. Pharmacists are commonly asked for medical advice in the community, and there is no current literature evaluating what pharmacists are recommending for infant teething. The objectives of this study were to evaluate what pharmacists are currently recommending for infant teething treatment and assess what percentage would inappropriately recommend a benzocaine-containing product. METHODS: From March to June 2016, a 16-item in-person paper-and-pen questionnaire was administered to 200 pharmacists in the San Francisco Bay area at 115 outpatient over-the-counter pharmacies. Questions included demographic information, work and educational background, infant teething recommendations, and preferred educational resources. RESULTS: The overall response rate was 94.3%. One-half (50.5%) of the pharmacists' approaches to infant teething treatment was to recommend a nondrug option first and then, if needed, an over-the-counter medication. A majority (63.0%) of the pharmacists surveyed would inappropriately select a benzocaine-containing product. CONCLUSION: Despite warnings, the majority of pharmacists would still inappropriately recommend a benzocaine-containing product for treatment of infant teething. Further education is warranted to ensure that all pharmacists, health care providers, and consumers are aware of the potential harm of benzocaine use in infants.

Comparative evaluation of effectiveness of intra-pocket anesthetic gel and injected local anesthesia during scaling and root planing - A split-mouth clinical trial.

BACKGROUND AND AIM: Pain control is an important outcome measure for successful periodontal therapy. Injected local anesthesia has been used to secure anesthesia for scaling and root planing (SRP) and continues to be the anesthetic of choice for pain control. Alternatively, intra-pocket anesthetic gel has been used as an anesthetic during SRP. Hence, this clinical trial was done to compare the effectiveness of intra-pocket anesthetic gel and injected local anesthesia during SRP and also to assess the influence of intra-pocket anesthetic gel on treatment outcomes in chronic periodontitis patients. MATERIALS AND METHODS: Fifteen systemically healthy chronic periodontitis patients were recruited. The dental quadrants on right side received either intra-pocket 20% benzocaine gel (Gel group) or infiltration/block by 2% lidocaine with 1:80,000 adrenaline (injection group). Quadrants on the left side received the alternative. Pain perception and patients preference for the type of anesthesia was recorded. Clinical parameters: plaque index, modified gingival index, modified sulcular bleeding index, probing pocket depth, and clinical attachment level were recorded at baseline and 1 month after treatment. RESULTS: No difference was observed in visual analog scale (P > 0.05) and verbal rating scale (P > 0.05) pain perception between gel group and injection group. A slightly increased preference to gel as anesthesia (53% vs. 47%) was observed. The treatment outcome after SRP did not show a significant difference between gel and injection group (P > 0.05). CONCLUSION: Intra-pocket administration of 20% benzocaine gel may be effective for pain control during SRP and may offer an alternative to conventional injection anesthesia.

A Randomized Trial to Evaluate the Effect of Two Topical Anesthetics on Pain Response During Frenotomy in Young Infants.

Objective: To examine the comparative effectiveness of two topical anesthetics in controlling the pain associated with tongue-tie release (frenotomy) in young infants. Design: Randomized trial. Setting: A Pediatric Craniofacial Clinic. Subjects: Forty-two infants who were referred for frenotomy were randomly allocated to receive the topical anesthetic gel 2% tetracaine or 20% benzocaine applied prior to frenotomy. Frenotomies were videotaped. The primary outcome measure was the Neonatal Facial Coding System (NFCS) score. Secondary outcome measures included cry duration and a visual analog scale (VAS) assessed by the parents. Results: The two groups were comparable with regard to weight, age, gender, previous painful experience, and last feeding time. Median NFCS scores prior to frenotomy in the tetracaine and the benzocaine groups were 4.5 (IQR: 0.75­10.2) and 3.5 (IQR: 0­9.5), respectively (P = 0.89, 95% CI −3 to 4). During frenotomy, median NFCS score increased to 28 (IQR: 24.5­30.25) in the tetracaine group (P < 0.0001, median difference −22, 95% CI −24.5 to −19), and to 28 (IQR: 26­30) in the benzocaine group (P < 0.0001, median difference −23, 95% CI −27 to −17). Mean cry durations in the tetracaine and the benzocaine groups were 69.4 seconds and 63.9 seconds, respectively (P = 0.32, 95% CI −47 to 15), and mean VAS scores were 57.2 and 58.2, respectively (P = 0.89, 95% CI −15.2 to 13.4). Conclusions: These topical anesthetics seem ineffective in controlling the pain associated with frenotomy. Clinicians should continue to search for an effective treatment for this procedure.

Effect of 5% benzocaine gel on relieving pain caused by fixed orthodontic appliance activation. A double-blind randomized controlled trial.

AIM: To compare the effectiveness of 5% benzocaine gel and placebo gel on reducing pain caused by fixed orthodontic appliance activation. SETTING AND SAMPLE POPULATION: Thirty subjects (15-25 years) undergoing fixed orthodontics. METHODS AND MATERIALS: A randomized, double-blind, placebo-controlled and cross-over clinical trial study was conducted. Subjects were asked to apply a placebo gel and 5% benzocaine gel, exchangeable in two consecutive appointments, twice a day for 3 days and mark their level of pain on a VAS scale. The pain severity was evaluated by means of Mann-Whitney U-test for comparing two gel groups, Kruskal-Wallis nonparametric test for overall differences and post hoc test of Dunnett for paired multiple comparisons. p-value was assigned <0.05. RESULTS: The overall mean value of pain intensity for benzocaine and placebo gels was 0.89 and 1.15, respectively. The Mann-Whitney U-test indicated that there was no significant difference between overall pain in both groups (mean difference = 0.258 p ˂ 0.21). For both groups, pain intensity was significantly lower at 2, 6 and 24 h compared with pain experienced at days 2, 3 and 7. CONCLUSION: Benzocaine gel caused a decrease in pain perception at 2 h compared with placebo gel. Peak pain intensity was at 2 h for placebo gel and at 6 h for benzocaine gel, followed by a decline in pain perception from that point to day 7 for both gels.

Effectiveness of benzocaine in reducing deep cavity restoration and post-extraction stress in dental patients.

OBJECTIVES: To investigate the effectiveness of topical anesthetic, 20% benzocaine in relieving pain and stress in patients following deep cavity restoration and extraction of teeth under local anesthesia (LA). METHODS: A prospective clinical trial was conducted from October 2014 until April 2015 at Taibah University, Al Madinah Al Munawarah, Kingdom of Saudi Arabia. Forty-five patients were included in the 20% benzocaine group, and 46 in the normal saline group. Evaluation of the dental stress was made pre-operatively and immediately post-operative treatment using the visual analogue scale (VAS). Furthermore, discomfort of the injections were recorded by the patients after each treatment on standard 100 mm VAS, tagged at the endpoints with "no pain" (0 mm) and "unbearable pain" (100 mm). RESULTS: There were statistically significant differences between the mean stress scores for patients in the benzocaine and normal saline groups post-operatively (p=0.002). There were significant differences between the mean pain scores for patients in the post buccal injection (p=0.001), post palatal injection (p=0.01), and the post inferior alveolar nerve block groups (p=0.02). Buccal, palatal, and inferior alveolar nerve block injections were more painful for patients in the normal saline group than the benzocaine group. CONCLUSION: This investigation has demonstrated that post-operative stress associated with deep cavity restoration and dental extractions under LA can be reduced by the application of topical anesthetic (20% benzocaine) at the operative site for intra-oral injections.

Topical intrapocket anesthesia during scaling and root planing: a randomized clinical trial.

Although the use of injectable anesthesia prior to subgingival scaling and root planing (SRP) reduces pain, many patients report fear and prolonged numbness of adjacent tissues. The aim of the present study was to compare the effects of a eutectic mixture containing 25 mg/g of lidocaine and 25 mg/g of prilocaine, injectable 2% lidocaine, topical 2% benzocaine and a placebo substance on reducing pain during SRP. In this randomized, split-mouth, masked clinical trial, thirty-two patients presenting more than two teeth with probing depth and clinical attachment level ≥ 5 mm in at least 4 sextants were randomly allocated to four groups: EMLA(r); injectable 2% lidocaine; topical 2% benzocaine and placebo. Pain and discomfort were measured using a visual analogue scale (VAS) and verbal scale (VS). Repeated-measures analysis of variance and Poisson regression were used for analysis. Patient satisfaction with the anesthesia was determined at the end of each treatment session. VAS and VS scores did not differ between injectable 2% lidocaine and EMLA (p > 0.05) and both substances showed significantly better pain control compared to 2% benzocaine and placebo (p < 0.05). 93.7% and 81.2% of the individuals were satisfied with the injectable anesthetic and EMLA, respectively (p = 0.158). Dissatisfaction with benzocaine and placebo was approximately 10 times greater than injectable anesthesia (p = 0.001). In conclusion, EMLA showed an equivalent effect on pain control when compared to the injectable anesthesia and performed better than 2% benzocaine in SRP. Thus, EMLA is a viable anesthetic option during scaling and root planning, despite the frequent need for second application.

Topical Intrapocket Anesthesia During Scaling and Root Planing: a Randomized Clinical Trial

Although the use of injectable anesthesia prior to subgingival scaling and root planing (SRP) reduces pain, many patients report fear and prolonged numbness of adjacent tissues. The aim of the present study was to compare the effects of a eutectic mixture containing 25 mg/g of lidocaine and 25 mg/g of prilocaine, injectable 2% lidocaine, topical 2% benzocaine and a placebo substance on reducing pain during SRP. In this randomized, split-mouth, masked clinical trial, thirty-two patients presenting more than two teeth with probing depth and clinical attachment level ≥5 mm in at least 4 sextants were randomly allocated to four groups: EMLA(r); injectable 2% lidocaine; topical 2% benzocaine and placebo. Pain and discomfort were measured using a visual analogue scale (VAS) and verbal scale (VS). Repeated-measures analysis of variance and Poisson regression were used for analysis. Patient satisfaction with the anesthesia was determined at the end of each treatment session. VAS and VS scores did not differ between injectable 2% lidocaine and EMLA (p>0.05) and both substances showed significantly better pain control compared to 2% benzocaine and placebo (p<0.05). 93.7% and 81.2% of the individuals were satisfied with the injectable anesthetic and EMLA, respectively (p=0.158). Dissatisfaction with benzocaine and placebo was approximately 10 times greater than injectable anesthesia (p=0.001). In conclusion, EMLA showed an equivalent effect on pain control when compared to the injectable anesthesia and performed better than 2% benzocaine in SRP. Thus, EMLA is a viable anesthetic option during scaling and root planning, despite the frequent need for second application.

Embora a anestesia injetável previamente a raspagem e alisamento subgengival (RASUB) reduza a dor, muitos pacientes relatam medo e amortecimento prolongado dos tecidos adjacentes. O objetivo deste estudo foi comparar o efeito de uma mistura eutética contendo 25mg/g de lidocaína e 25 mg/g de prilocaína, lidocaína 2% injetável, benzocaína 2% tópica e um placebo na redução da dor durante a RASUB. Neste ensaio clínico randomizado, cego de boca dividida, trinta e dois pacientes que apresentavam mais que dois dentes com profundidade de sondagem e nível de inserção clínica ≥ 5 mm, em no mínimo 4 sextantes, foram randomicamente alocados em 4 grupos: EMLA(r), lidocaína 2% injetável, benzocaína 2% tópica ou placebo. Dor e desconforto foram mensurados usando uma Escala Visual Analógica (EVA) e Escala Verbal (EV). A satisfação dos pacientes com a anestesia foi determinada ao final de cada consulta. Análise de variância de medidas repetidas e regressão de Poisson foram usadas para análise. Os escores da EVA e EV não demonstraram diferenças estatisticamente significantes entre lidocaína injetável e EMLA(r) (p > 0,05) e ambas as substâncias demonstraram significativamente melhor controle da dor comparadas a benzocaína 2% e placebo (p<0,05). 93,7% e 81,2% dos indivíduos ficaram satisfeitos com o anestésico injetável e EMLA(r), respectivamente (p=0,158). A insatisfação com a benzocaína e placebo foi aproximadamente 10 vezes maior do que com a anestesia injetável (p=0,001). Em conclusão, o EMLA(r) demonstrou um efeito equivalente no controle da dor quando comparado com a anestesia injetável e melhor do que a benzocaína 2% em RASUB. Assim, o EMLA(r) é uma opção anestésica viável durante a raspagem e alisamento radicular, apesar da necessidade frequente de segunda aplicação.

Randomized controlled trial of benzocaine versus placebo spray for pain relief at hysterosalpingogram.

Many women experience pain during hysterosalpingogram (HSG). This prospective, randomized, double-blinded, placebo-controlled study assessed whether the use of benzocaine spray during HSG is associated with reduced pain as compared with placebo. Thirty women presenting for HSG were enrolled and randomized to either benzocaine or saline spray. Treatment groups were similar in age, race, parity, pre-procedure oral analgesic use and history of dysmenorrhoea and/or chronic pelvic pain. Median change in pain score from baseline to procedure was 50.6mm (-7.4 to 98.8mm) in the benzocaine group and 70.4mm (19.8 to 100mm) in the placebo group. There was no difference between groups after adjusting for history of dysmenorrhoea. There was no difference in resolution of pain in benzocaine versus placebo groups at 5 min post procedure--median pain score difference -11.1 (-90.1 to 18.5) versus -37.0 (-100 to 1.2)--or at 30 min post procedure. Satisfaction scores did not differ by treatment and did not correlate with pain score during the procedure (rho=0.005). The use of benzocaine spray does not significantly improve pain relief during HSG nor does it hasten resolution of pain post HSG. Of interest, patient satisfaction was not correlated with pain. Many women experience pain during hysterosalpingogram (HSG), which is a test used to evaluate the uterine cavity and fallopian tube. We conducted a prospective, randomized, double-blinded, placebo-controlled study to assess whether the use of benzocaine spray during HSG is associated with reduced pain as compared with placebo. Thirty women presenting for HSG were enrolled and randomized to either benzocaine or saline spray. Treatment groups were similar in age, race, previous pregnancies, pre-procedure oral analgesic use and history of dysmenorrhoea (painful periods) and/or chronic pelvic pain. There was no difference in pain scores or resolution of pain between the two groups. Satisfaction scores did not differ by treatment group and did not correlate with the pain score during the procedure. We conclude that the use of benzocaine spray does not significantly improve pain relief during HSG nor does it hasten resolution of pain post HSG. Of interest, patient satisfaction was not correlated with pain.

[The development of severe methemoglobinemia in patients receiving "Almagel A"].

This clinical case and the literature review show possible development of methemoglobinemia due to the use of local anesthetics, included in drugs for the gastrointestinal diseases treatment, in particular benzocaine, which is the methaemoglobin forming agent. These drugs are common and often taken by the patients themselves without any control. The aim of our paper is to draw the attention of physicians to the risk of the widely known drug administration which can be purchased without a prescription.

The effect of topical anesthetic hydration on the depth of thermal injury from the plasma skin regeneration device.

BACKGROUND AND OBJECTIVES: The plasma skin regeneration (PSR) device delivers thermal energy to the skin by converting nitrogen gas to plasma. Prior to treatment, hydration of the skin is recommended as it is thought to limit the zone of thermal damage. However, there is limited data on optimal hydration time. This pilot study aims to determine the effect of topical anesthetic application time on the depth of thermal injury from a PSR device using histology. STUDY DESIGN/MATERIALS AND METHODS: PSR (1.8 and 3.5 J) was performed after 0, 30, or 60 minutes of topical anesthetic application. Rhytidectomy was then performed and skin was fixed for histologic analysis. Four patients (two control and four treatment sites per patient) undergoing rhytidectomy were recruited for the study. Each patient served as his/her own control (no hydration). A scoring system for tissue injury was developed. Epidermal injury, the presence of vacuolization, blistering, damage to adnexal structures, and depth of dermal collagen changes were evaluated in over 1,400 high-power microscopy fields. RESULTS: There was a significant difference in the average thermal injury score, depth of thermal damage, and epidermal injury when comparing controls to 30 minutes of hydration (P = 0.012, 0.012, 0.017, respectively). There was no statistical difference between controls and 60 minutes of hydration or between 30 and 60 minutes of hydration. Epidermal vacuolization at low energy and patchy distribution of thermal injury was also observed. CONCLUSION: Topical hydration influences the amount of thermal damage when applied to skin for 30 minutes prior to treatment with the PSR device. There was a trend toward decreasing thermal damage at 60 minutes, and there was no difference between treatment for 30 or 60 minutes. The data suggest that application of topical anesthetic for a short period of time prior to treatment with the PSR device is cost-effective, safe, and may be clinically beneficial.

The analgesic effect of benzocaine mucoadhesive patches on orthodontic pain caused by elastomeric separators, a preliminary study.

OBJECTIVES: To study the effect of benzocaine mucoadhesive patches (20%) on orthodontic pain caused by elastomeric separators. SUBJECTS AND METHODS: A split-mouth design was used in 30 patients (12 female, 18 male, aged 23 ± 3.75 years). They were instructed to apply benzocaine and placebo patches randomly for right or left first permanent molars of maxillary/mandibular arches for 20 min and repeat this procedure every 6 h with a similar type patch. A 10 cm Visual Analogue Scale (VAS) was used for pain perception assessment in patients who were given benzocaine (benzocaine group) or placebo (placebo group) patches. Pain perception (VAS) was recorded immediately after separator placement and after 2, 6, 12, 18, 24, 48 and 72 h. RESULTS: The mean VAS (SD) for the placebo and benzocaine groups were 2.28 (1.08) and 1.63 (0.67), respectively. The pain peaked at 24 h. Significant pain perception differences were observed between groups at 2, 18, 24, 48 and 72 h. Pain perception was not different between genders or jaws investigated (p > 0.05). The Friedman test revealed significant differences in pain perception among various time intervals for benzocaine (χ (2) = 99.84, p = 0.000) and placebo (χ (2) = 102.361, p = 0.000) groups. Significant negative correlations (ρ) were found only between pain perception scores and patient's ages in the placebo group at 18 (-0.438), 24 (-0.526), 48 (-0.565) and 72 h (-0.458). CONCLUSION: The recorded mean VAS values were relatively low; however, the benzocaine 20% patches significantly reduced the post-separation orthodontic pain.

Development, characterization, and in vitro and in vivo evaluation of benzocaine- and lidocaine-loaded nanostructrured lipid carriers.

The present study concerns the in vitro and in vivo evaluation of benzocaine (BENZO) and lidocaine (LIDO) topical delivery from nanostructured lipid carriers (NLCs). Morphology and dimensional distribution of NLCs have been, respectively, characterized by differential scanning calorimetry (DSC) and photon correlation spectroscopy. The release pattern of BENZO and LIDO from NLCs was evaluated in vitro determining drug percutaneous absorption through excised human skin. Radiant heat tail-flick test was carried out in mice to determine the antinociceptive effect of BENZO and LIDO from NLC. DSC studies revealed that the inner oil phase of NLC plays a significant role in stabilizing the particle architecture and increasing the drug solubility. In vitro evidences show that BENZO and LIDO, when incorporated in viscosized NLC dispersions, exhibited a lower flux with respect to formulations containing the free drugs in the aqueous phase. In vivo study enabled to demonstrate that BENZO and LIDO can be released in a prolonged fashion when incorporated into lipid carriers. The results obtained pointed out NLC capability to act as an effective drug reservoir, thus prolonging the anesthetic effect of BENZO and LIDO.