• Journal of Pharmaceutical Investigation
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• v.12 no.2
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• pp.31-36
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• 1982

The effect of some surfactants, such as tween 40, tween 80, span 80, and triethanolamine, on the absorption of lidocaine was studied using goldfish as a model of absorption kinetics. This model was believed that reciprocal overturn time and death time were the occurrence of biological effect versus drug absorption. The results were as follows; The threshold concentration of lidocaine was significantly reduced by the surfactants. Overturn time and death time of goldfish in the lidocaine solution were reduced by such surfactants as tween 40, tween 80, span 80 and triethanolamine, and more reduced with increasing concentration of surfactants except tween 40 and tween 80. The plots of reciprocal death time versus lidocaine concentration were linear relationship with a positive concentration intercept such as minimum effective concentration (0.2-0.8%). As results it is believed that these surfactants may form complexes with lidocaine or affect the goldfish membrane to make more permeable to lidocaine, which is adsorbed more rapidly.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.2
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• pp.69-76
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• 2015

Background: There have been few studies on the effect of an elevated concentration of lidocaine hydrochloride in the surgical removal of an impacted lower third molar. This study aimed to examine the efficacy of 4% lidocaine along with 1:100,000 epinephrine compared to 2% lidocaine along with 1:100,000 epinephrine as inferior alveolar nerve block for the removal of an impacted lower third molar. Methods: This single-blind study involved 31 healthy patients (mean age: 23 y; range: 19-33 y) with symmetrically impacted lower third molars as observed on panoramic radiographs. Volunteers required 2 surgical interventions by the same surgeon with a 3-week washout period. The volunteers were assigned either 4% lidocaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine as local anesthetic during each operation. Results: We recorded the time of administration, need for additional anesthetic administration, total volume of anesthetic used. We found that the patient's preference for either of the 2 types of local anesthetic were significantly different (P < 0.05). However, the extent of pulpal anesthesia, surgical duration, and duration of soft tissue anesthesia were not significantly different. Conclusions: Our study suggested that inferior alveolar nerve block using 4% lidocaine HCl with 1:100,000 epinephrine as a local anesthetic was clinically more effective than that using 2% lidocaine HCl with 1:100,000 epinephrine; the surgical duration was not affected, and no clinically adverse effects were encountered.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.251-255
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• 2010

A local anesthetic agent which is most commonly used for outpatients is lidocaine hydrochloride that contains epinephrine, which is for vasoconstriction in 1:100,000 concentration. This agent is known as a safe local anesthetic agent and has been used widely for topical use or injections. However, the allergic reaction that we will report in this case occurred when common local anesthesia was done intraorally, and the patient complained of hyperventilation, tachycardia, abdominal pain and unintentional tears. We experienced an allergic reaction after injecting the lidocaine hydrochloride and therefore report the case to suggest that local anesthesia should be always carried out very carefully.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.3
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• pp.121-128
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• 2015

Background: The authors studied the hemodynamic effect influent by using the novel high concentration of lidocaine HCl for surgical removal impacted lower third molar. The objective of this study was to evaluate the hemodynamic change when using different concentrations of lidocaine in impacted lower third molar surgery. Methods: Split mouth single blind study comprising 31 healthy patients with a mean age of 23 years (range 19-33 years). Subjects had symmetrically impacted lower third molars as observed on panoramic radiograph. Each participant required 2 surgical interventions by the same surgeon with a 3-week washout period washout period. The participants were alternately assigned one of two types of local anesthetic (left or right) for the first surgery, then the other type of anesthetic for the second surgery. One solution was 4% lidocaine with 1:100,000 epinephrine and the other was 2% lidocaine with 1:100,000 epinephrine. A standard IANB with 1.8 ml volume was used. Any requirement for additional anesthetic and patient pain intra-operation was recorded. Post-operatively, patient was instructed to fill in the patient report form for any adverse effect and local anesthetic preference in terms of intra-operative pain. This form was collected at the seven day follow up appointment. Results: In the 4% lidocaine group, the heart rate increased during the first minute post-injection (P < 0.05). However, there was no significant change in arterial blood pressure during the operation. In the 2% lidocaine group, there was a significant increase in arterial blood pressure and heart rate in the first minute following injection for every procedure. When the hemodynamic changes in each group were compared, the 4% lidocaine group had significantly lower arterial blood pressure compared to the 2% lidocaine group following injection. Post-operatively, no adverse effects were observed by the operator and patient in either local anesthetic group. Patients reported less pain intra-operation in the 4% lidocaine group compared with the 2% lidocaine group (P < .05). Conclusions: Our results suggest that a 4% concentration of lidocaine HCl with 1:100,000 epinephrine has better clinical efficacy than 2% lidocaine HCl with 1:100,000 epinephrine when used for surgical extraction of lower third molars. Neither drug had any clinical adverse effects.

• Membrane Journal
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• v.17 no.1
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• pp.67-79
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• 2007

Uniform microcapsules containing ionic model drugs were prepared by controlling various conditions of emulsification procedure using a lab-scale membrane emulsification system with a SPG (Shirasu porous glass) tubular membrane. We observed the effects of various emulsification parameters [concentration and molecular weight of polycaprolatone (PCL) polymer, transmembrane pressure and emulsifier concentration in disperse phase and continuous phase, stirring speed] on the mean size and size ditribution of microcapsules containing lidocaine hydrochloride (cationic drug), sodium salicylate (nonionic drug) and 4-acetaminophen (anionic drug) used as a model drugs. Also, release characteristics of a model drugs from PCL microcapsules were investigated. Controlling membrane emulsification parameters, uniform PCL microcapsules with about $5\;{\mu}m$ of the mean size were finally prepared. The release rate and the burst effect of microcapsules were decreased in condition of the acidic solution, but it was increased in condition of the base solution.

• Archives of Craniofacial Surgery
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• v.23 no.4
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• pp.183-186
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• 2022

Plastic surgery around the eyes is usually performed under local anesthesia, using a mixture of lidocaine and epinephrine. Blindness is a rare but devastating complication after the injection of local anesthesia in this region. Most cases reported to date have been caused by occlusion of the ophthalmic artery or central retinal artery. In this case report, however, we present a highly unusual case of blindness caused by corneal edema after a local anesthetic injection. A patient visited the emergency room with a laceration on the eyebrow, and local anesthesia was injected before suturing. Immediately after the injection, severe corneal edema developed, making it impossible to observe the structures in the anterior chamber in detail or check the light reflex and visual acuity of the naked eye. An antibiotic (moxifloxacin hydrochloride) and high-concentration steroid eyedrops were promptly applied. High-concentration steroids were also administered orally. On day 13 post-injury, the visual acuity of the naked eye improved to 1.0, and no recurrence of corneal lesions was observed. Although the cause of corneal edema after the local injection could not be conclusively identified, we hope that this report will help raise clinicians' awareness of this complication and appropriate treatment methods.