midazolam hydrochloride - Medication Listings

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ·HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with artificial bitterness modifier, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, mixed fruit flavor, sodium benzoate, sodium citrate, sorbitol, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form. chemical-structure-1.jpg chemical-structure-2.jpg midazolam-chart.jpg

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium, with 1% benzyl alcohol as preservative; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 •HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 3.6 for the 5 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. Midazolam-SPL-Structure Midazolam-SPL-Structure-01 Midazolam-SPL-Graph

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium, with 1% benzyl alcohol as preservative; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C18H13ClFN3•HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 3.6 for the 5 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolamsplstructure1 midazolamsplstructure2 midazolamsplfigure

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ·HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with bitterness modifier, artificial cherry-brandy flavor, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, sodium benzoate, sodium citrate, sodium saccharin, sorbitol solution, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form. chemical structure Equilibrium Mixture pH Dependance chart

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium, with 1% benzyl alcohol as preservative; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C18H13ClFN3•HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 3.6 for the 5 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolamsplstructure1 midazolamsplstructure2 midazolamsplfigure

Midazolam hydrochloride injection is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg or 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% disodium edetate, with 1% benzyl alcohol as preservative; the pH is adjusted to approximately 3 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white to light yellow crystalline compound, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 ∙HCl, a calculated molecular weight of 362.24 and the following structural formula: Chemical Structure

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4] benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ∙HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with bitterness modifier, artificial cherry-brandy flavor, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, sodium benzoate, sodium citrate, sodium saccharin, sorbitol solution, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form. Chemical Structure Chemical Structure Image

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 •HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 4.0 for the 1 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolam-spl-structure-1 midazolam-spl-structure-2 midazolam-spl-fig-1

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4] benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ∙HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with bitterness modifier, artificial cherry-brandy flavor, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, sodium benzoate, sodium citrate, sodium saccharin, sorbitol solution, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form. Chemical Structure Chemical Structure Image

Midazolam hydrochloride injection is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg or 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% disodium edetate, with 1% benzyl alcohol as preservative; the pH is adjusted to approximately 3 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white to light yellow crystalline compound, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 ∙HCl, a calculated molecular weight of 362.24 and the following structural formula: Chemical Structure

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium, with 1% benzyl alcohol as preservative; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ, is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 •HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 3.6 for the 5 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolam-spl-structure-1 midazolam-spl-structure-2 midazolam-spl-figure

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ·HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with bitterness modifier, artificial cherry-brandy flavor, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, sodium benzoate, sodium citrate, sodium saccharin, sorbitol solution, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. Midazolam Open-ring Form The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolam1-chem.jpg midazolam2-black.jpg midazolam-hydroch-04.jpg

Midazolam is a benzodiazepine available as midazolam HCl syrup for oral administration. Midazolam, a white to light yellow crystalline compound, is insoluble in water, but can be solubilized in aqueous solutions by formation of the hydrochloride salt in situ under acidic conditions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4 H -imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C 18 H 13 ClFN 3 ·HCl, a calculated molecular weight of 362.25 and the following structural formula: Each mL of the syrup contains midazolam hydrochloride equivalent to 2 mg midazolam compounded with artificial bitterness modifier, citric acid anhydrous, D&C Red #33, edetate disodium, glycerin, mixed fruit flavor, sodium benzoate, sodium citrate, sorbitol, and water; the pH is adjusted to 2.8 to 3.6 with hydrochloric acid. Under the acidic conditions required to solubilize midazolam in the syrup, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the syrup, the solution may contain up to about 40% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart below plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 2.8 to 3.6. Above pH 5, at least 99% of the mixture is present in the closed-ring form.

Midazolam hydrochloride injection is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg or 5 mg midazolam compounded with 0.8% sodium chloride. The pH is adjusted to approximately 3 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white to light yellow crystalline compound, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ , is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 ∙HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed-ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 4.0 for the 1 mg/mL concentration and 3.0 to 3.6 for the 5 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. Formula1.jpg Formula2.jpg Image1.jpg

Midazolam hydrochloride is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium; the pH is adjusted to 2.9 to 3.5 with hydrochloric acid and, if necessary, sodium hydroxide. Midazolam is a white or yellowish crystalline powder, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ, is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine hydrochloride. Midazolam hydrochloride has the empirical formula C 18 H 13 ClFN 3 •HCl, a calculated molecular weight of 362.25 and the following structural formula: Under the acidic conditions required to solubilize midazolam in the product, midazolam is present as an equilibrium mixture (shown below) of the closed ring form shown above and an open-ring structure formed by the acid-catalyzed ring opening of the 4,5-double bond of the diazepine ring. The amount of open-ring form is dependent upon the pH of the solution. At the specified pH of the product, the solution may contain up to about 25% of the open-ring compound. At the physiologic conditions under which the product is absorbed (pH of 5 to 8) into the systemic circulation, any open-ring form present reverts to the physiologically active, lipophilic, closed-ring form (midazolam) and is absorbed as such. The following chart plots the percentage of midazolam present as the open-ring form as a function of pH in aqueous solutions. As indicated in the graph, the amount of open-ring compound present in solution is sensitive to changes in pH over the pH range specified for the product: 3.0 to 4.0 for the 1 mg/mL concentration. Above pH 5, at least 99% of the mixture is present in the closed-ring form. midazolam-spl-structure-1 midazolam-spl-structure-2 midazolam-spl-figure