A anestesia local normalmente precede a maioria dos procedimentos odontológicos. Porém, por ser realizada por processo invasivo (injetável), muitas vezes afugentam o paciente do consultório. Portanto, a substituição do processo invasivo por não invasivo, além de inovador traria diversas vantagens a odontologia i.e., possibilitaria o aprimoramento de procedimentos rotineiros e cirúrgicos devido à provável redução de custos, submissão do paciente, facilidade de aplicação e menores riscos de contaminação e intoxicações. Neste intuito, filmes poliméricos hidrofílicos mono ou trilaminados, compostos pelo polímero mucoadesivo HPMC K100 LV, glicerol ou PEG 400 como plastificantes, e contendo os anestésicos locais cloridratos de prilocaína (PCL) e lidocaína (LCL) em diferentes proporções foram desenvolvidos. Os filmes apresentaram flexibilidade e moldabilidade adequadas, além de uniformidade de massa e teor. Tanto a massa total de fármaco nos filmes (11 - 55 mg/0,64cm2), quanto suas contribuições relativas nas misturas (0 - 100% m.m-1) modularam seus perfis e cinéticas de liberação e permeação, além das quantidades retidas no epitélio esofageal suíno. Quantidades menores dos fármacos conduziram aos maiores coeficientes de permeabilidade do LCL. O filme contendo mistura dos fármacos na proporção 1:1 (PCL:LCL) apresentou a melhor relação custo/benefício e foi escolhida para a continuidade dos estudos. O aumento na massa total de fármaco nos filmes de 12,5 para 25 mg aumentou significativamente sua força e trabalho de mucoadesão, mas reduziu sua resistência à tração e módulo de elasticidade. Os filmes apresentaram propriedades mecânicas e de mucoadesão adequadas para a finalidade proposta. A adição de camadas oclusiva (composta por Eudragit® S100 e trietil citrato como plastificante) e mucoadesiva (composta por HPMC K100 LV e policarbofil na proporção 3:1 m.m-1 e PEG 400 como plastificante) aos filmes reduziu significativamente as quantidades dos fármacos liberadas, permeadas e retidas no epitélio e, portanto, a composição e arquitetura dos patches trilaminados deve ser aprimorada de modo a favorecer a hidratação da camada de liberação. Pela primeira vez foi demonstrada a eficiência da técnica de iontoforese (1 mA.cm-2) na promoção da permeação destes fármacos em associação a partir de filmes poliméricos. Para que possa substituir a anestesia injetável (solução a 2%, equivalente a 36 mg de fármaco), a permeação dos fármacos a partir do filme mais promissor (12,5 mg de PCL:LCL 1:1, 3% m.m-1 HPMC K100LV e 30% PEG400 em função da massa de polímero mucoadesivo) deve ser aumentada em pelo menos 30 vezes. / Local anesthesia typically precedes the majority of dental procedures. However, due to be performed using an invasive process (injection), often it scares the patient out from the dentist office. Accordingly, besides its innovative character, the replacement of the painful injection by a noninvasive process might bring several advantages to the dentistry field. It might enable the improvement of routinely and surgical procedures as a function of cost saving, patient compliance, ease of application and lowering the risk of contamination and intoxication. In this pursuit, we developed hydrophilic polymeric films comprised by one or three layers, comprised by the mucoadhesive polymer HPMC K100 LV, glycerol or PEG 400 as plasticizers, and containing the local anesthetic drugs prilocaine (PCL) and lidocaine (LCL) hydrochloride in different proportions. The films showed suitable flexibility and plasticity, besides uniformities of mass and content. Both the total mass of drugs in the films (11 - 55 mg/0.64 cm2), and their relative contribution in the mixtures (0 - 100% w.w-1) have modulated their profiles and kinetics of both delivery and permeation, as well as their amount retained in the porcine esophageal epithelium. Lower drug loadings lead to an increase on the permeability coefficient of LCL. The film containing the drugs blended on a 1:1 (PCL:LCL) proportion has presented the most acceptable cost/benefit ratio. Hence, it was chosen for further investigations. Increasing the total amount of drug in the film from 12.5 to 25 mg significantly raised their force and work of mucoadhesion. On the other hand, it have decreased their tensile strength and elastic modulus. The films presented suitable mechanical e mucoadhesive properties for our purposes. Adding the mucoadhesive (comprised by HPMC K100 LV and polycarbophil at 3:1 w.w-1 and PEG400 as plasticizer) and occlusive (Eudragit® S100 and triethyl citrate as plasticizer) layers on the delivery layer has significantly decreased the amount of drug released, permeated and retained on the epithelium from the films. Thereby, both composition and architecture of the patches must be refined in order to improve the hydration of the delivery layer. For the first time it was presented the efficiency of iontophoresis (1 mA.cm-2) on the permeation enhancement of these drug in association from polymeric films. To reach the replacement of infiltrative anesthesia (2% solution, equivalent to 36 mg of drug), the amount of drug permeated from the most promising film (12.5 mg of PCL:LCL 1:1, 3% w.w-1 HPMC K100LV and 30% PEG400 as a function of the mass of mucoadhesive polymer) must be improved in at least 30 folds.

A anestesia local normalmente precede a maioria dos procedimentos odontológicos. Porém, por ser realizada por processo invasivo (injetável), muitas vezes afugentam o paciente do consultório. Portanto, a substituição do processo invasivo por não invasivo, além de inovador traria diversas vantagens a odontologia i.e., possibilitaria o aprimoramento de procedimentos rotineiros e cirúrgicos devido à provável redução de custos, submissão do paciente, facilidade de aplicação e menores riscos de contaminação e intoxicações. Neste intuito, filmes poliméricos hidrofílicos mono ou trilaminados, compostos pelo polímero mucoadesivo HPMC K100 LV, glicerol ou PEG 400 como plastificantes, e contendo os anestésicos locais cloridratos de prilocaína (PCL) e lidocaína (LCL) em diferentes proporções foram desenvolvidos. Os filmes apresentaram flexibilidade e moldabilidade adequadas, além de uniformidade de massa e teor. Tanto a massa total de fármaco nos filmes (11 - 55 mg/0,64cm2), quanto suas contribuições relativas nas misturas (0 - 100% m.m-1) modularam seus perfis e cinéticas de liberação e permeação, além das quantidades retidas no epitélio esofageal suíno. Quantidades menores dos fármacos conduziram aos maiores coeficientes de permeabilidade do LCL. O filme contendo mistura dos fármacos na proporção 1:1 (PCL:LCL) apresentou a melhor relação custo/benefício e foi escolhida para a continuidade dos estudos. O aumento na massa total de fármaco nos filmes de 12,5 para 25 mg aumentou significativamente sua força e trabalho de mucoadesão, mas reduziu sua resistência à tração e módulo de elasticidade. Os filmes apresentaram propriedades mecânicas e de mucoadesão adequadas para a finalidade proposta. A adição de camadas oclusiva (composta por Eudragit® S100 e trietil citrato como plastificante) e mucoadesiva (composta por HPMC K100 LV e policarbofil na proporção 3:1 m.m-1 e PEG 400 como plastificante) aos filmes reduziu significativamente as quantidades dos fármacos liberadas, permeadas e retidas no epitélio e, portanto, a composição e arquitetura dos patches trilaminados deve ser aprimorada de modo a favorecer a hidratação da camada de liberação. Pela primeira vez foi demonstrada a eficiência da técnica de iontoforese (1 mA.cm-2) na promoção da permeação destes fármacos em associação a partir de filmes poliméricos. Para que possa substituir a anestesia injetável (solução a 2%, equivalente a 36 mg de fármaco), a permeação dos fármacos a partir do filme mais promissor (12,5 mg de PCL:LCL 1:1, 3% m.m-1 HPMC K100LV e 30% PEG400 em função da massa de polímero mucoadesivo) deve ser aumentada em pelo menos 30 vezes. / Local anesthesia typically precedes the majority of dental procedures. However, due to be performed using an invasive process (injection), often it scares the patient out from the dentist office. Accordingly, besides its innovative character, the replacement of the painful injection by a noninvasive process might bring several advantages to the dentistry field. It might enable the improvement of routinely and surgical procedures as a function of cost saving, patient compliance, ease of application and lowering the risk of contamination and intoxication. In this pursuit, we developed hydrophilic polymeric films comprised by one or three layers, comprised by the mucoadhesive polymer HPMC K100 LV, glycerol or PEG 400 as plasticizers, and containing the local anesthetic drugs prilocaine (PCL) and lidocaine (LCL) hydrochloride in different proportions. The films showed suitable flexibility and plasticity, besides uniformities of mass and content. Both the total mass of drugs in the films (11 - 55 mg/0.64 cm2), and their relative contribution in the mixtures (0 - 100% w.w-1) have modulated their profiles and kinetics of both delivery and permeation, as well as their amount retained in the porcine esophageal epithelium. Lower drug loadings lead to an increase on the permeability coefficient of LCL. The film containing the drugs blended on a 1:1 (PCL:LCL) proportion has presented the most acceptable cost/benefit ratio. Hence, it was chosen for further investigations. Increasing the total amount of drug in the film from 12.5 to 25 mg significantly raised their force and work of mucoadhesion. On the other hand, it have decreased their tensile strength and elastic modulus. The films presented suitable mechanical e mucoadhesive properties for our purposes. Adding the mucoadhesive (comprised by HPMC K100 LV and polycarbophil at 3:1 w.w-1 and PEG400 as plasticizer) and occlusive (Eudragit® S100 and triethyl citrate as plasticizer) layers on the delivery layer has significantly decreased the amount of drug released, permeated and retained on the epithelium from the films. Thereby, both composition and architecture of the patches must be refined in order to improve the hydration of the delivery layer. For the first time it was presented the efficiency of iontophoresis (1 mA.cm-2) on the permeation enhancement of these drug in association from polymeric films. To reach the replacement of infiltrative anesthesia (2% solution, equivalent to 36 mg of drug), the amount of drug permeated from the most promising film (12.5 mg of PCL:LCL 1:1, 3% w.w-1 HPMC K100LV and 30% PEG400 as a function of the mass of mucoadhesive polymer) must be improved in at least 30 folds.

Myringotomy plays an important role in otological therapy. The procedure requires an efficient anesthesia, which can be obtained without general anesthesia. However, the use of local anesthetics on the tympanic membrane (TM) has been abandoned in many places, as general anesthesia has been readily available. In the present study the effects of some commonly used topical anesthetics on the TM structure and inner ear were tested in an animal model (rat and guinea pig).Four different anesthetic compounds—Xylocaine®, Bonain's liquid, phenol and Emla®—were applied to the TMs of the animals, which were sacrificed 10 minutes to 5 months after application. Morphological effects regarding time after treatment and number of applications were elucidated. At sacrifice the tissue was fixed and the TMs analysed by light microscopy (LM) and transmission electron microscopy (TEM). In nine animals phenol, Xylocaine® Spray or Emla® was applied to the round window niche and ABR recordings were made at 24 h to 6 months after exposure. After the final ABR evaluation the animals were sacrificed and the cochleae prepared for LM and scanning electron microscopy (SEM).On the TM phenol and Bonain's liquid caused instant destruction of the keratinizing stratified squamous epithelium followed by long-lasting hyperplasia of this epithelium and the underlying connective tissue. A pronounced hyperplasia of these two layers was also noted for the Xylocaine® Spray group, but without immediate destruction of the keratinizing epithelium. The extent of structural changes differed in relation to the extent of spreading of the agent. Emla® showed little, if any, sign of epithelial reaction and had no effect on the connective tissue. Regarding the inner ear Emla®, Xylocaine® Spray and phenol induced significantly impaired ABR thresholds mainly affecting the higher frequencies. However, the impaired ABR thresholds were reversible and at the end of the experiment there was no significant impairment compared to the control data. All agents, except Xylocaine®, damaged the hair cells in the basal part of the cochlea as shown by cytocochleogram and SEM analysis.Instant destruction of the epidermis seems to be necessary for an instant anesthetic effect. All agents caused profound connective tissue reactions. The manner of application, depending on the physical properties of the agent, determined the extent of the structural changes. The changes of the connective tissue were concentrated to the submucosal layer, which seems to be the area for reconstruction of the damaged TM. All agents caused functional inner ear changes. With the exception of Xylocaine® they also caused morphological alterations of the cochlea. The functional changes were partly reversible. Topical anesthetics applied to the TM should be used with caution and when used in an appropriate manner they can be considered safe, especially in an inflamed middle ear, with a thickened round window membrane, which should prevent the agents from reaching the inner ear structures. / digitalisering@umu