Efficacy of liposome-encapsulated 0.5% ropivacaine in maxillary dental anaesthesia

Inclusion Complex between Local Anesthetic/2-hydroxypropyl-β-cyclodextrin in Stealth Liposome

The drugs delivery system in the treatment of diseases has advantages such as reduced toxicity, increased availability of the drug, etc. Therefore, studies of the supramolecular interactions between local anesthetics (LAs) butamben (BTB) or ropivacaine (RVC) complexed with 2-hydroxypropyl-β-cyclodextrin (HP-βCD) and carried in Stealth liposomal (SL) are performed. ¹H-NMR nuclear magnetic resonance (DOSY and STD) were used as the main tools. The displacements observed in the ¹H-NMR presented the complexion between LAs and HP-βCD. The diffusion coefficients of free BTB and RVC were 7.70 × 10⁻¹⁰ m² s⁻¹ and 4.07 × 10⁻¹⁰ m² s⁻¹, and in the complex with HP-βCD were 1.90 × 10⁻¹⁰ m² s⁻¹ and 3.64 × 10⁻¹⁰ m² s⁻¹, respectively, which indicate a strong interaction between the BTB molecule and HP-βCD (98.3% molar fraction and Ka = 72.279 L/mol). With STD-NMR, the encapsulation of the BTB/HP-βCD and RVC/HP-βCD in SL vesicles was proven. Beyond the saturation transfer to the LAs, there is the magnetization transfer to the hydrogens of HP-βCD. BTB and RVC have already been studied in normal liposome systems; however, little is known of their behavior in SL.

A meta-analysis on the efficacy of the ropivacaine infiltration in comparison with other dental anesthetics

OBJECTIVES

The aim of this meta-analysis was to assess the clinical efficacy and safety profile of ropivacaine in comparison with other dental anesthetics in different clinical conditions. MATERIALS AND METHODS: This meta-analysis was registered in the National Institute for Health Research PROSPERO (ID: CRD42020205580). PubMed and Scholar Google were consulted to identify clinical trials using ropivacaine in comparison with other local anesthetic drugs for any dental procedure. Articles comparing ropivacaine and other dental anesthetics were assessed with the Cochrane Collaboration's risk of bias tool. Data from reports without a high risk of bias were extracted (anesthetic and adverse effects) and analyzed using the Review Manager Software 5.3. for Windows and the Risk Reduction Calculator.

RESULTS

Ropivacaine produces a longer anesthetic time when compared with lidocaine/adrenaline (n = 260; p = 0.00001) and similar anesthesia than bupivacaine (n = 190).

CONCLUSIONS

Data of this study indicate that ropivacaine infiltration produces a longer anesthetic time when compared with lidocaine and articaine but not when compared to bupivacaine in dental procedures.

CLINICAL RELEVANCE

Ropivacaine was more effective than lidocaine for dental anesthesia. For this reason, the manufacture of a ropivacaine dental cartridge with a suitable concentration could be an important advancement for clinical practice.

Anesthetic efficacy in vital asymptomatic teeth using different local anesthetics: a systematic review with network meta-analysis

OBJECTIVES

This study aimed to evaluate the efficacy of various local anesthesia (LA) in vital asymptomatic teeth.

MATERIALS AND METHODS

Randomized controlled trials comparing pulpal anesthesia of various LA on vital asymptomatic teeth were included in this review. Searches were conducted in the Cochrane CENTRAL, MEDLINE (via PubMed), EMBASE, ClinicalTrials.gov, Google Scholar and 3 field-specific journals from inception to May 3, 2019. Study selection, data extraction, and risk of bias assessment using Cochrane Risk of Bias Tool were done by 2 independent reviewers in duplicate. Network meta-analysis (NMA) was performed within the frequentist setting using STATA 15.0. The LA was ranked, and the surface under the cumulative ranking (SUCRA) line was plotted. The confidence of the NMA estimates was assessed using the CINeMA web application.

RESULTS

The literature search yielded 1,678 potentially eligible reports, but only 42 were included in this review. For maxillary buccal infiltration, articaine 4% with epinephrine 1:100,000 was more efficacious than lidocaine 2% with epinephrine 1:100,000 (odds ratio, 2.11; 95% confidence interval, 1.14-3.89). For mandibular buccal infiltration, articaine 4% with epinephrine 1:100,000 was more efficacious than various lidocaine solutions. The SUCRA ranking was highest for articaine 4% with epinephrine when used as maxillary and mandibular buccal infiltrations, and lidocaine 2% with epinephrine 1:80,000 when used as inferior alveolar nerve block. Inconsistency and imprecision were detected in some of the NMA estimates.

CONCLUSIONS

Articaine 4% with epinephrine is superior when maxillary or mandibular infiltration is required in vital asymptomatic teeth.

Overcoming barriers by local drug delivery with liposomes

Localized or topical administration of drugs may be considered as a potential approach for overcoming the problems caused by the various biological barriers encountered in drug delivery. The combination of using localized administration routes and delivering drugs in nanoparticulate formulations, such as liposomes, may have additional advantages. Such advantages include prolonged retention of high drug loads at the site of action and controlled release of the drug, ensuring prolonged therapeutic effect; decreased potential for side-effects and toxicity (due to the high topical concentrations of drugs); and increased protection of drugs from possible harsh environments at the site of action. The use of targeted liposomal formulations may further potentiate any acquired therapeutic advantages. In this review we present the most advanced cases of localized delivery of liposomal formulations of drugs, which have been investigated pre-clinically and clinically in the last ten years, together with the reported therapeutic advantages, in each case.

Palatal needle-free anesthesia for upper molars extraction. A randomized clinical trial

BACKGROUND

The aim of this study was to compare the ability of liposomal and non-liposomal lidocaine and prilocaine in hydrogel formulations to promote topical anesthesia in palatal mucosa during upper molar extractions.

METHODS

In this randomized, cross over, triple-blinded clinical trial, a liposomal and a non-liposomal formulation of the eutectic mixture of local anesthetics, 2.5% lidocaine and 2.5% prilocaine, were used to promote palatal anesthesia without the local anesthetic infiltration during bilateral upper molars extractions.

RESULTS

From the total of 40 patients included in this study, the non-liposomal eutectic lidocaine-prilocaine formulation failed in 40% of cases, unlike the liposomal formulation, which was effective for all patients (Fisher's exact test, p < 0.0001). Furthermore, the liposomal formulation (26.75 ± 7,47 min) induced longer anesthesia duration (t-test, p < 0.0001) than the non-liposomal formulation (16.78 ± 4.75 min). No mucosal ulceration or discomfort was reported for both formulations.

CONCLUSION

The liposomal formulation was able to induce adequate anesthesia in palatal mucosa during dental extraction, avoiding the local anesthetic infiltration. For the first time, a topical formulation allowed upper molars surgical removal without injection of any local anesthetic agent into palatal mucosa in adults.

Current progress and challenges of nanoparticle-based therapeutics in pain management

Pain is a widespread and growing health problem worldwide that exerts a considerable social and economic impact on both patients and healthcare systems and, therefore, on society in general. Although current treatment modalities include a wide variety of pharmacological and non-pharmacological approaches, due to the complexity of pain and individual differences in clinical response these options are not always effective in mitigating and relieving pain. In addition, some pain drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), local anesthetics and opioids show several unfavorable side effects. Therefore, current research advances in this medical field are based on the development of potential treatments to address many of the unmet needs and to overcome the existing limitations in pain management. Nanoparticle drug delivery systems present an exciting opportunity as alternative platforms to improve efficacy and safety of medications currently in use. Herein, we review a broad range of nanoparticle formulations (organic nanostructures and inorganic nanoparticles), which have been developed to encapsulate an array of painkillers, paying special attention to the key advantages that these systems offer, (compared to the use of the free drug), as well as to the more relevant results of preclinical studies in animal models. Additionally, we will briefly discuss the impact of some of these nanoformulations in clinical trials.

Topical Ropivacaine in Prevention of Post-Tonsillectomy Pain in Adults

BACKGROUND

Post-tonsillectomy pain is 1 of the most intense postoperative pain conditions. However, optimal and sufficient postoperative analgesic treatment remains unclear. We investigated the effect of topical ropivacaine for post-tonsillectomy pain in 160 adult outpatient surgery patients over 2 postoperative weeks.

METHODS

At the end of tonsillectomy, 2 swabs soaked in either 1% ropivacaine or saline were packed into the tonsillar beds for 5 minutes. We used ibuprofen and a combination of acetaminophen (500 mg)-codeine (30 mg) tablets as postoperative analgesics for 2 weeks. The primary outcome was pain intensity on swallowing measured on a numeric rating scale (NRSs) during the first postoperative week expressed as area under curve (AUC). The secondary endpoints included the worst pain experienced during the 2-hour follow-up in the postanesthesia care unit, pain intensity during the second postoperative week, and the number of ibuprofen and acetaminophen-codeine tablets consumed during the 2 postoperative weeks.

RESULTS

During the first postoperative week, 120 patients out of 160 (75%) provided complete results, including data on their use of analgesics according to the instructions as well as completed and returned a questionnaire daily. A total of 101 patients (63%) did the same during the second postoperative week.Median (interquartile range [IQR]) of the primary outcome NRSs (AUC) was 38 (19) for the ropivacaine group and 37 (24) for the control group during the first postoperative week (P = .77, -1.0 estimated difference; 95% confidence interval [CI] for the difference, -7.0 to 5.0); no difference was found. Median (IQR) of NRS at rest (NRSr) (AUC) was 24.5 (19) for the ropivacaine group and 24 (22) for the control group during the first postoperative week (P = .96, 0.0 estimated difference; 95% CI for the difference, -5.0 to 5.0); no difference was found. Median (IQR) of the worst pain intensity values (NRSs or NRSr) (AUC) was 5 (3) for the ropivacaine group and 5 (3) for the control group (P = .44, 0.0 estimated difference; 95% CI for the difference, -1.0 to 0.5); no difference was found. During the second postoperative week, median (IQR) of the NRSs (AUC) was 17 (13) for the ropivacaine group and 21 (23) for the control group (P = .05, -4.0 estimated difference; 95% CI for the difference, -9.0 to 0.0) and median (IQR) of the NRSr (AUC) 10.5 (10) for ropivacaine group and 11 (13) for the control group (P = .42, -1.0 estimated difference; 95% CI for the difference, -5.0 to 2.0); no difference was found.The number of rescue analgesics (acetaminophen-codeine tablets) consumed during the second postoperative week was lower in the ropivacaine group than in the control group (median [IQR] of the consumption [AUC] was 10 [12] for the ropivacaine group and 16 [12] for the control group; P = .0008, -7.0 estimated difference; 95% CI of difference, -10 to -3.0). The groups showed no differences in overall risk for post-tonsillectomy bleeding. However, bleeding requiring hemostasis under local anesthesia was more common in the ropivacaine group (18% vs 8%, P = .048, 10% estimated difference; 95% CI for the difference, 0%-21%).

CONCLUSIONS

Topical ropivacaine failed to reduce pain intensity during the first postoperative week. We observed no major adverse effects.

Anaesthetic efficacy of unilamellar and multilamellar liposomal formulations of articaine in inflamed and uninflamed tissue

We compared the efficacy of articaine encapsulated in multilamellar and unilamellar liposomes with that of articaine with epinephrine, after infiltration into inflamed and uninflamed tissue in rats. We encapsulated 4% articaine in multilamellar (articaine:multi) and unilamellar (articaine:uni) liposomes and compared them with 4% articaine with 1:100 000 epinephrine (articaine:epinephrine), in inflamed (plantar incision into the hind paw) and uninflamed (infraorbital nerve block) tissue in rats. Anaesthetic formulations (0.1ml) were injected near the right infraorbital foramen in uninflamed tissue, where success and duration of anaesthesia were assessed by pinching the upper lip every 5 minutes. For inflamed tissue the anaesthetic formulations (0.1ml) were injected laterally into a surgical wound made 24 hours earlier in the plantar region of the rat's right hind paw. The degree of anaesthesia was assessed by application of forces laterally to the wound with electronic von Frey filaments. Articaine:uni resulted in less successful anaesthesia than both articaine:multi (p=1.1x10(-5)) and articaine:epinephrine (p=4.3x10(-8)) in uninflamed tissue, but there were no differences in duration or success of anaesthesia between articaine:epinephrine and articaine:multi. In inflamed tissue articaine:epinephrine gave significantly more effective anaesthesia for longer than articaine:uni (p=2.3x10(-6)), and articaine:epinephrine (p=1.8x10(-6)) formulations, which did not differ from each other. Multilamellar liposomal articaine could be an option for local anaesthesia in uninflamed tissues. However, articaine with epinephrine gave better results than liposomal formulations in inflamed tissue.

Local Anesthetics: What's New in Minimal Pain Injection and Best Evidence in Pain Control

SUMMARY

Local anesthesia in plastic surgery is undergoing a revolution. In the last 10 years, significant improvements in technique have permitted surgeons to do more and more under pure local anesthesia to increase patient safety and convenience while maintaining total patient comfort during the injection of the local anesthesia and while the procedure is accomplished. Many procedures which used to require sedation are now being performed without it. This article explores some of the new advances in local anesthesia such as painless blunt-tipped cannula local anesthetic infiltration, decreased pain with sharp needle tip injection, and long-lasting local anesthetics with delayed release from liposomal encapsulation. This article also examines the best evidence of the last 10 years of advances of pain control with local anesthesia.

Interactions of liposomes with dental restorative materials

The in vitro adsorption and retention of liposomes onto four common types of dental restorative materials (conventional and silorane-based resin composites as well as conventional and resin-modified glass ionomer cements (GIC)) have been investigated due to their potential use in the oral cavity. Uncoated liposomes (positively and negatively charged) and pectin (low- and high-methoxylated) coated liposomes were prepared and characterized in terms of particle size and zeta potential. The adsorption of liposomes was performed by immersion, quantified by fluorescence detection, and visualized by fluorescence imaging and atomic force microscopy. Positive liposomes demonstrated the highest adsorption on all four types of materials likely due to their attractive surface charge. They also retained well (minimum 40% after 60 min) on both conventional resin composite and GIC even when exposed to simulated salivary flow. Although an intermediate initial level of adsorption was found for the pectin coated liposomes, at least 70% high methoxylated-pectin coated liposomes still remained on the conventional resin composite after 60 min flow exposure. This indicates significant contribution of hydrophobic interactions in the prolonged binding of liposomes to resin composites. Based on these results, the present paper suggests two new possible applications of liposomes in the preservation of dental restorations.

A review of oral surgery-related papers published in the British Journal of Oral and Maxillofacial Surgery during 2011 and 2012

This paper is a synopsis of all articles relating to oral surgery that were published in the British Journal of Oral and Maxillofacial Surgery (BJOMS) between January 2011 and December 2012. Of the 57 published, 40 (70%) were full-length articles that predominantly focused on implantology, dentoalveolar surgery, and bisphosphonate osteonecrosis of the jaws (BONJs). In addition, a number of short communications, technical notes, and letters to the editor described rare cases, unusual complications, and novel surgical techniques.