Local anaesthetics have been implemented extensively in the case of a variety of painful superficial procedures, venipuncture, skin graft harvesting, anal or genital pruritus, poison ivy rashes, postherpetic neuralgia and several other dermatoses. The dilemma with commercially available local acting anaesthetics is that it may take well up to an hour to produce an anaesthetic effect. Anaesthetics have to traverse the highly efficient barrier, the stratum corneum, in order to reach the intended target site which is the free nerve endings located in the dermis. The objective of this study was to compare the transdermal delivery of an eutectic combination of two ionisable amide types of local anaesthetics, lidocaine HCI and prilocaine HCI, delivered with the novel Pheroid™ technology to that of a commercially available product in order to establish whether the lag time could be significantly reduced. Several techniques of promoting the penetration of these anaesthetics have previously been employed, including occlusive dressing, entrapment in liposomes and miscelles, iontophoretic delivery and so forth. The Pheroid™ delivery system is novel technology that entails improved delivery of several active compounds. It is a submicron emulsion type formulation that possesses the ability to be transformed in morphology and size, thereby affording it tremendous flexibility. Since it primarily consists of unsaturated essential fatty acids, it is not seen as foreign to the body but rather as a skin-friendly carrier. Vertical Franz cell diffusion studies were performed over a 12 hour period using Caucasian female abdominal skin obtained, with the consent of the donor, from abdominoplastic surgery. Comparison was made between the commercial product EMLA® cream, the active local anaesthetics dissolved in phosphate buffered solution (PBS) and the active ingredients entrapped within Pheroid™ vesicles. Distinct entrapment could be ascertained visually by confocal laser scanning microscopy (CLSM). The amount of drug that traversed the epidermal membrane into the receptor phase was then assayed by high performance liquid chromatography (HPLC). The results obtained with the Pheroid™ vesicles revealed a biphasic character with rapid permeation during the first two hours, followed by a plateau between 3 to 12 hours. The initial dramatic increase in percentage yield and flux indicates that the Pheroid™ carrier enhances the transdermal delivery of the actives in order to accelerate the onset of action. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

Local anaesthetics have been implemented extensively in the case of a variety of painful superficial procedures, venipuncture, skin graft harvesting, anal or genital pruritus, poison ivy rashes, postherpetic neuralgia and several other dermatoses. The dilemma with commercially available local acting anaesthetics is that it may take well up to an hour to produce an anaesthetic effect. Anaesthetics have to traverse the highly efficient barrier, the stratum corneum, in order to reach the intended target site which is the free nerve endings located in the dermis. The objective of this study was to compare the transdermal delivery of an eutectic combination of two ionisable amide types of local anaesthetics, lidocaine HCI and prilocaine HCI, delivered with the novel Pheroid™ technology to that of a commercially available product in order to establish whether the lag time could be significantly reduced. Several techniques of promoting the penetration of these anaesthetics have previously been employed, including occlusive dressing, entrapment in liposomes and miscelles, iontophoretic delivery and so forth. The Pheroid™ delivery system is novel technology that entails improved delivery of several active compounds. It is a submicron emulsion type formulation that possesses the ability to be transformed in morphology and size, thereby affording it tremendous flexibility. Since it primarily consists of unsaturated essential fatty acids, it is not seen as foreign to the body but rather as a skin-friendly carrier. Vertical Franz cell diffusion studies were performed over a 12 hour period using Caucasian female abdominal skin obtained, with the consent of the donor, from abdominoplastic surgery. Comparison was made between the commercial product EMLA® cream, the active local anaesthetics dissolved in phosphate buffered solution (PBS) and the active ingredients entrapped within Pheroid™ vesicles. Distinct entrapment could be ascertained visually by confocal laser scanning microscopy (CLSM). The amount of drug that traversed the epidermal membrane into the receptor phase was then assayed by high performance liquid chromatography (HPLC). The results obtained with the Pheroid™ vesicles revealed a biphasic character with rapid permeation during the first two hours, followed by a plateau between 3 to 12 hours. The initial dramatic increase in percentage yield and flux indicates that the Pheroid™ carrier enhances the transdermal delivery of the actives in order to accelerate the onset of action. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

Os anestésicos locais têm sido utilizados na clínica médica e odontológica com o objetivo de atenuar a dor nos procedimentos cirúrgicos. Tais fármacos são administrados usualmente por meio do uso de agulhas, o que pode diminuir o número de pacientes nos consultórios dentários, afugentados pelo medo desses dispositivos invasivos. Comprimidos mucoadesivos de dissolução rápida podem ser promissores em incorporar esses anestésicos e assim liberá-los topicamente com a finalidade de promover a anestesia de forma não invasiva. Neste intuito, comprimidos de dissolução rápida contendo os anestésicos locais cloridratos de prilocaína (PCL) e lidocaína (LDC) foram desenvolvidos por três métodos: i) compressão direta; ii) compressão após pré-processamento dos adjuvantes em secagem por atomização e iii) liofilização. Estes foram comparados em relação ao tempo de hidratação e desintegração para a escolha de uma plataforma para estudos de liberação, permeação e mucoadesão in vitro. Filme polimérico oclusivo com Eudragit S100 foi moldável e flexível para a finalidade de revestimento parcial. A massa total de desintegrantes nos comprimidos modularam sua hidratação e desintegração. Os comprimidos obtidos por liofilização apresentaram menores valores de tempo de hidratação e desintegração. Os efeitos de diluente (manitol), desintegrante (glicolato sódico de amido), promotores químicos de permeação (ácido oleico, Tween® 80 e propilenoglicol) e polímeros mucoadesivos (HPMC e pullulan) sobre liberação em éster de celulose e permeação em esôfago suíno foram avaliados. Os comprimidos apresentaram rápida liberação em uma hora. A liberação obedeceu a cinética de primeira ordem e o mecanismo de liberação foi governado pelo transporte não fickiano. A proporção de manitol e tipo de polímero mucoadesivo não teve influência significativa nos estudos de liberação. A quantidade de fármacos liberada diminuiu em comprimidos com desintegrantes e promotores químicos de permeação. Um significante efeito sinérgico entre polímero mucoadesivo e promotores químicos no coeficiente de permeabilidade, fluxo e retenção de fármacos na mucosa foi observado. Quando comparado com comprimidos de HPMC com promotores químicos, o pullulam melhorou a permeação de fármacos através da mucosa. Mucoadesão dos comprimidos com diferentes polímeros foi avaliado. HPMC e pullulan melhoraram as propriedades mucoadesivas. Todos os comprimidos se mantiveram aderidos na região do epitélio durante uma hora. A nova plataforma de liberação de fármacos obtida pela combinação de tecnologias farmacêuticas de comprimidos por liofilização, com adição de promotores de permeação e pullulan como polímero mucoadesivo mostrou uma estratégia efetiva para o desenvolvimento de um sistema transbucal para LDC e PRC que pode ser usada para melhorar anestésica sem uso de agulhas / Local anesthetics have been used in medical and dental practice aiming at to become less painful some surgical procedures. Such drugs are typically administered through needles along surgical procedures, which decrease the number of patients in the dental offices, once many people are afraid of these invasive devices. Fast dissolving and mucoadhesive tablets could be promising for incorporating these anesthetics and thus releasing them topically in order to improve noninvasive anesthesia. Herein, it were developed fast dissolving tablets containing the local anesthetic drugs prilocaine (PRC) and lidocaine (LDC) hydrochloride. Three methods were used: a) direct compression of the mixture of components; b) pre-processing by spray drying adjuvants and c) freeze drying and these tablets. The tablets were compared in terms of wetting and disintegration time for the choice of a platform for further in vitro release, permeation and mucoadhesion studies. An occlusive polymeric film of Eudragit S100 showed suitable flexibility and plasticity according to purpose of coating the tablets. The total mass of disintegrants in formulations affected the wetting and disintegration of the tablets. Freeze dryed tablets had lower wetting and disintegration time values as compared to the others. The effects of diluent (mannitol), disintegrant (sodium starch glycolate), chemical enhancers (oleic acid, Tween® 80 and propylene glycol) and mucoadhesive polymers (hydroxypropyl methylcellulose and pullulan) on the drug release from cellulose ester membrane and drug permeation through porcine esophageal mucosa were evaluated. Dissolution test showed fast release on one hour. The drug release data fit well to the First order expression and the release mechanism was non-Fickian transport. No significant influence of proportion of mannitol and type of mucoadhesive polymer on release studies was observed. Release of drugs decreased in tablets with disintegrant and chemical enhancers. A significant synergic effect between the mucoadhesive polymer and chemical enhancers on the permeability coefficient, flux and retention of drugs on mucosa was observed. As compared to HPMC for tablets containing chemical enhancers, pullulan improved the drug permeation through the mucosa. Mucoadhesion to tablets with different polymers was evaluated. HPMC and pullulan improve mucoadhesive properties. All tablets maintained in the attachment site of the epithelium for at least one hour. It conclusion, the novel drug delivery platform achieved by combining the pharmaceutical technologies of freeze-dryed tablets comprising chemical enhancers and pullulan as mucoadhesive polymer displayed an effective strategy for the development of a transbuccal system for LDC and PRC that can be used to improve needle-free buccal anesthesia.

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.