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Abstract: Objectives: Squamous cell carcinoma (SCC) is a malignant disease that affects the oral cavity. Lidocaine has shown antiproliferative and cytotoxic activity on several cell types. The rapid dispersion is a limitation issue; however, the complexation in cyclodextrin improved pharmacological features and modified the drug release. This study investigated the effects of lidocaine (lido) complexed with 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD‐lido) on cell viability and proliferation of human tongue squamous cell carcinoma SCC9 and SCC25. Methods: The complex formation was confirmed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Cells SCC9 and SCC25 were exposed to lido and HP‐β‐CD‐lido (40–4000 μ m), and the effects on cell viability (MTT) and antiproliferative activity (SRB) were tested. Key findings: Differential scanning calorimetry and SEM results demonstrated the occurrence of host–guest interaction. Lido and HP‐β‐CD‐lido (4000 μ m) significantly reduced the viability of SCC9 cells to 83% and 63%, respectively. The viability of SCC25 treated with lido, and HP‐β‐CD‐lido (4000 μ m) was 71% and 44%, respectively. Lido (4000 μ m) reduced the proliferation of SCC9 and SCC25 to 39.5% and 23.7%, respectively. HP‐β‐CD‐lido (4000 μ m) was cytotoxic for both cell lines. Conclusions: HP‐β‐CD was able to potentiate the in vitro cytotoxic effects of lidocaine on human squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

Objectives Oxethazaine ( OXZ) is one of the few local anaesthetics that provides analgesia at low pH, but presents poor solubility, cytotoxicity and no parenteral formulations. To address these issues, we aimed to prepare OXZ host-guest inclusion complex with hydroxypropyl-beta-cyclodextrin ( HP-β- CD). Methods The inclusion complex was formed by co-solubilization, followed by a job plot analysis to determine stoichiometry of complexation and dialysis equilibrium analysis (based on UV/ VIS absorption and fluorescence profiles of OXZ). Complex formation was confirmed by phase-solubility data, X-ray, Scanning Electron Microscopy and DOSY-1H- NMR experiments. In vitro cytotoxicity was analysed by MTT test in 3T3 fibroblasts. In vivo analgesia was tested by Von Frey test (inflammatory wounds - rats). Key findings Oxethazaine complexed (1 : 1 molar ratio) with HP-β- CD, as indicated by loss of OZX crystalline structure (X-ray) and strong host: guest interaction ( NMR, K = 198/ M), besides increased solubility. In vitro cell survival improved with the complex ( IC50 OXZ = 28.9 μ m, OXZ : HP-β- CD = 57.8 μ m). In addition, the complex (0.1% OXZ) promoted in vivo analgesia for the same time that 2% lidocaine/epinephrine did. Conclusion Our results show that complexation improved physicochemical and biological properties of OXZ, allowing its application to inflamed tissues by parenteral routes. [ABSTRACT FROM AUTHOR]

This blinded crossover study evaluated the efficacy and pain sensitivity evoked by a previously reported liposome-encapsulated mepivacaine formulation (Araujo et al., 2004). Thirty healthy volunteers received an intraoral injection (1.8 mL), at four different sessions, of the following formulations: 2% mepivacaine with 1:100,000 epinephrine (MVC2%EPI), 3% mepivacaine (MVC3%), and 2 and 3% liposome-encapsulated mepivacaine (MVC2%LUV and MVC3%LUV). Latency period and duration of anesthesia were assessed by an electrical pulp tester and injection discomfort by a visual analog scale (VAS). Data were analyzed with Tukey-Kramer and Friedman tests ( P < 0.05). No significant difference was found regarding latency period (in minutes) among the formulations ( P > 0.05). The duration of anesthesia after the injection of MVC3%LUV was higher than the one obtained after the infiltration of MVC2%LUV and of MVC3% ( P < 0.05). However, the duration of anesthesia obtained with MVC3% did not differ from the one obtained with MVC2%LUV ( P > 0.05). MVC3%LUV showed lower VAS median values than MVC2%EPI ( P < 0.05), and there were no significant differences among the others formulations. Liposome-encapsulated 3% mepivacaine showed longer duration of anesthesia, in comparison to the commercial formulation of MVC3%. MVC2%LUV was able to produce a similar duration of anesthesia as the 3% commercial formulation, despite the 50% decrease in the anesthetic concentration. Thus, the encapsulation of mepivacaine increased the duration of anesthesia and reduced the injection discomfort caused by vasoconstrictor-associated formulations in healthy volunteers. [ABSTRACT FROM AUTHOR]

Abstract: Study Objective: To compare the topical and the pulpal anesthesia efficacy of liposomal and plain benzocaine formulations. Design: Double-blinded, randomized crossover study. Setting: University ambulatory dental center. Patients: 30 ASA physical status I volunteers. Interventions: Volunteers received, in three different sessions, topical application of liposome-encapsulated 10% benzocaine (LB10), 10% benzocaine gel (B10), and 20% benzocaine gel (B20) in the right maxillary canine mucobuccal fold. Measurements: Pain associated with the needle insertion was rated by visual analog scale (VAS) and the duration of topical anesthesia was recorded. Pulpal anesthesia was evaluated using an electric pulp tester. Main Results: VAS values (median, 1st - 3rd quartiles) were 17 cm (11 - 25), 14 cm (3 - 22), and 21 cm (9 – 21) for B10, LB10, and B20, respectively. No differences were noted among the groups (Friedman test; P = 0.58). Soft tissue anesthesia was also not different. The LB10 [10 (8 - 12) min] showed longer soft tissue anesthesia (Friedman test; P < 0.01) than the other agents [B10 = 8 (5 - 10) min, and B20 = 7 (6 - 9) min]. None of the topical benzocaine formulations tested induced pulpal anesthesia. Conclusions: The encapsulation of benzocaine into liposome increased the duration of soft tissue anesthesia. However, it did not induce pulpal anesthesia. [Copyright &y& Elsevier]