Preparation of Lidocaine

Diethylamine is an unpleasant-smelling and corrosive liquid. Measure it out in a hood. Should any of this chemical come in contact with the skin, flood the affected area with cold water. 

The solution oi8 Mpotassium hydroxide is highly caustic and can cause burns and loss of hair avoid contact of this solution with your skin. Wear latex gloves when transferring this solution. Should contact occur, flood the affected area with water and rinse it thoroughly with dilute aqueous acetic acid solution. 

Be certain there are no open flames in the vicinity when you are working with diethyl ether. Use flameless heating when concentrating diethyl ether solutions. 

Preparation Sign in at www.cengage.com/login to answer Pre-Lab Exercises, access videos, and read the MSDSs for the chemicals used or produced in this procedure. Review Sections 2.7, 2.9, 2.10, 2.11, 2.17, 2.21, 2.22, 2.28, and 2.29. 

Apparatus A 125-mL round-bottom flask, 250-mL Erlenmeyer flask, an ice-water bath, separatory funnel, apparatus for heating under reflux, magnetic stirring, vacuum filtration, simple distillation, and ffame/ess heating. 

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Bupivacaine is an anaesthetic with a slow onset but a long duration of action. It is indicated for continuous epidural analgesia in labour. Xylocoine is the proprietary preparation of lidocaine (lignocoine). Lidocoine injections ore used in dentistry. 

Note that local anaesthetic preparations of lidocaine often contain adrenaline (epinephrine), which may interact with beta blockers, see Beta blockers -I- Inotropes and Vasopressors , p.848. 

The preparation of lidocaine starts with the chemical reduction of 2,6-dimethylni-trobenzene (35) to give 2,6-dimethylaniline (36) using stannous chloride as a reducing agent (Eq. 21.20). In this reaction, stannous chloride, SnCl2, is oxidized to stannic chloride, SnCl4. This reduction is similar to the reduction of nitrobenzene to aniline, which was discussed in detail in Section 21.2 (Scheme 21.3), and the side reactions associated with this process are discussed in that section. 

What would be the expected effect on yield if only one mole of diethylamine per mole of 37 were used in the final step of the preparation of lidocaine Explain. 

Mueller-Goymann, C.C., and Frank, S.G., Interaction of lidocaine and lidocaine-hydrochloride with the liquid crystal structure of topical preparations, Int. J. Pharm., 29 147-159 (1986). 

Yahagi, R. Onishih, H. Machida, Y. Preparation and evaluation of double-phased mucoadhesive suppositories of lidocaine utilizing carbopol and white beeswax. J. Controlled Release 1999, 61, 1-8. 

In preparation for transesophageal echocardiogram, a 73-year-old woman was given 15 ml of lidocaine solution 2% and lidocaine spray 4% to anesthetize the oropharynx, plus intravenous midazolam 1 mg and pethidine 12.5 mg. She very rapidly became cyanosed, but remained... 

A 5-year-old child had 35 g of Emla apphed under an occlusive dressing to eczematous skin in preparation for cryotherapy for molluscum contagiosum (3). Within 1 hour, the child had a generalized seizure that lasted 10 minutes. The plasma concentrations of lidocaine and prilocaine 30 minutes later were 5.5 and 2.0 pg/ml, respectively, and 6 hours later, the methemoglobin concentration was 19%. The child was given vitamin C 500 mg intravenously, and 2 days later had a methemoglobin concentration of 0.3%. 

A choice of salts can also expand the formulation options for a material. The antimalarial agent a-(2-piperidyl)-3,6-bis(trifluoromethyl)-9-phenanthrene-methanol hydrochloride (Fig. 9) exhibited poor solubility, was delivered as an oral formulation, and required a single dosing of 750 mg (13). Seven salts and the free base were evaluated. The lactate salt was found to be 200 times as soluble as the hydrochloride salt (Table 3). This enhanced solubility would make it possible to reduce the oral dose to achieve the same therapeutic response as well as develop a parenteral formulation for the treatment of malaria. However, the case of lidocaine hydrochloride (Fig. 14) demonstrates that a compound limited to parenteral and topical formulations can be expanded to oral administration by changing to a salt form with acceptable physical properties (16). The hydrochloride salt was hygroscopic, difficult to prepare, and hard to handle. Six salts were evaluated for salt formation, solubility, and hygroscopicity. Other salts, such as phosphate, exhibited properties acceptable for dry pharmaceutical dosage forms. 

Lidocaine is absorbed rapidly after parenteral administration and from the gastrointestinal and respiratory tracts. Although it is effective when used without any vasoconstrictor, epinephrine decreases the rate of absorption, such that the toxicity is decreased and the duration of action usually is prolonged. In addition to preparations for injection, an iontophoretic, needle-free drug-delivery system for a solution of lidocaine and epinephrine (lontocaine) is available. This system generally is nsed for dermal procedures and provides anesthesia to a depth of np to 10 mm. 

The nurse is preparing to administer 2 g/500 mL of lidocaine, an antidysrhythmic, after administering a 100 mg intravenous bolus to a client with multifocal premature ventricular contractions (PVC). Which intervention should the nurse implement ... 

Okamoto, H. Nakamori, T. Arakawa, Y. lida, K. Danjo, K. Development of polymer film dosage forms of lidocaine for buccal administration. II. Comparison of preparation methods. J. Pharm. Sci. 2002, 91 (11), 2424-2432. 

Given the yields that you obtained in the laboratory, calculate the number of moles of 2,6-dimethylnitrobenzene (35) that would be needed to prepare one mole of lidocaine bisulfate (42). 

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