Potassium citrate, solution preparation

Solutions that contain sodium citrate/citric acid (Shohl s solution and Bicitra) provide 1 mEq/L (1 mmol/L) each of sodium and bicarbonate. Polycitra is a sodium/potassium citrate solution that provides 2 mEq/L (2 mmol/L) of bicarbonate, but contains 1 mEq/L (1 mmol/L) each of sodium and potassium, which can promote hyperkalemia in patients with severe CKD. The citrate portion of these preparations is metabolized in the liver to bicarbonate, while the citric acid portion is metabolized to C02 and water, increasing tolerability compared to sodium bicarbonate. Sodium retention is also decreased with these preparations. However, these products are liquid preparations, which may not be palatable to some patients. Citrate can also promote aluminum toxicity by augmenting aluminum absorption in the GI tract. 

Potassium citrate is prepared by adding either potassium bicarbonate or potassium carbonate to a solution of citric acid until effervescence ceases. The resulting solution is then filtered and evaporated to dryness to obtain potassium citrate. 

Citrated blood is diluted 1 10 with enzyme buffer solution, and preservative is added (H19). The buffer is prepared by dissolving 0.2 g of Clarase (Fisher Scientific Co., New York) in 100 ml citrate buffer (5 g potassium citrate monohydrate and 1 g citric acid monohydrate in 1000 ml distilled water, pH 5.6). The solution is incubated for 3 days at 37°. After incubation, it is autoclaved 15 minutes to stop enzymatic action and coagulate proteins. It is filtered, and 1.0, 1.5, and 2.0 ml of the supernatant is added to individual flasks and assayed. Control flasks are included to estimate pantothenic acid contamination of the enzyme. 

The following substance, namely magnesium acetate potassium citrate potassium hydroxide potassium nitrate and sodium chloride can also be assayed for their respective elements as shown in Table 25.1 below. However, all the respective solutions of the said pharmaceutical substance and their standard solutions must be prepared as prescribed in BP (1993) strictly to obtain the best results. 

Procedure (Note Refer to Lead Limit Test, Appendix TTTR, for the solutions and the control.) Add 3 mL of Ammonium Citrate Solution and 0.5 mL of Hydroxylamine Hydrochloride Solution to the Sample Solution, and make the combined solutions alkaline to phenol red TS with ammonium hydroxide. Add 10 mL of Potassium Cyanide Solution. Immediately extract the solution with successive 5-mL portions of Dithizone Extraction Solution, draining off each extract into another separator, until the last portion of dithizone solution retains its green color. Shake the combined extracts for 30 s with 20 mL of 1 100 nitric acid, and discard the chloroform layer. Add exactly 4 mL of Ammonia-Cyanide Solution and 2 drops of Hydroxylamine Hydrochloride Solution to the acid solution. Add 10 mL of Standard Dithizone Solution, and shake the mixture for 30 s. Filter the chloroform layer through an acid-washed filter paper into a Nessler tube, and compare the color with that of a standard prepared as follows Add 0.25 mL of the Standard Lead Solution containing 10 p,g/mL of lead (Pb) ion, 4 mL of Ammonia-Cyanide Solution, and 2 drops of Hydroxylamine Hydrochloride Solution to 20 mL of 1 100 nitric acid, and shake for 30 s with 10 mL of Standard Dithizone Solution. Filter through an acid-washed filter paper into a Nessler tube. The color of the Sample Solution does not exceed that in the control. 

Lead Determine as directed under Lead Limit Test, Appendix IIIB, using a Sample Solution prepared as follows Dissolve 625 mg of sample in 10 mL of water, add 2 mL of 1 2 nitric acid, and boil until brown fumes evolve. Add 10 mL of water, boil for 2 min, then cool and dilute with water to about 25 mL. Use 25 mL of Ammonium Citrate Solution, 1 mL of Potassium Cyanide Solution, 0.5 mL of Hydroxylamine Hydrochloride Solution, and 2.5 p-g of lead (Pb) ion in the control. 

Soluble, effervescent tablets are prepared by compression. In addition to active ingredients, they contain mixtures of acids (citric acid, tartaric acid) and sodium bicarbonate (NaHCOs) that release carbon dioxide when dissolved in water. The United States Pharmacopeia (USP) 24 includes the following seven monographs Acetaminophen for Effervescent Oral Solution Aspirin Effervescent Tablets for Oral Solution Potassium Bicarbonate Effervescent Tablets for Oral Solution Potassium Bicarbonate and Potassium Chloride for Effervescent Oral Solution Potassium Bicarbonate and Potassium Chloride Effervescent Tablets for Oral Solution Potassium and Sodium Bicarbonates and Citric Acid for Oral Solution and Potassium Chloride, Potassium Bicarbonate, and Potassium Citrate Effervescent Tablets for Oral Solution. ... 

In patients with Stage 3 or higher CKD, the use of aUcalinizing salts, such as sodium bicarbonate or citrate/citric acid preparations, is useful to replenish depleted body bicarbonate stores. Sodium bicarbonate tablets are manufactured in 325- and 650-mg strengths (a 650-mg tablet contains 7.7 mEq sodium and 7.7 mEq bicarbonate). Shohl s solution and Bicitra contain 1 mEq/mL of sodium and the equivalent of 1 mEq/mL of bicarbonate as sodium citrate/citric acid. Citrate is metabolized in the liver to bicarbonate, and citric acid is metabolized to CO2 and water. Polycitra, which contains potassium citrate, (1 mEq/mL of sodium, 1 mEq/mL of potassium, and 2 mEq/mL of bicarbonate) should not be used in patients with severe CKD since hyperkalemia may result. 

Europium amalgam is very easily prepared by this method. Simultaneously, some potassium amalgam is formed. After the electrolysis, the latter may be removed nearly completely by action of water, which scarcely attacks europium amalgam as long as any potassium amalgam remains. Ytterbium and samarium are the only other rare earth metals that yield amalgams by the electrolysis of their acetate-citrate solutions. The electrical efficiency is high for europium, considerably less for ytterbium, and small for samarium. 

Highly soluble salts (for example sodium fluoride, potassium chloride, potassium citrate) are preferably not prepared in a capsule at all, since rapid dissolution can result in a high local concentration that may be harmful to the mucosa of the gastro-intestinal tract. An enteric coating on capsules and tablets can protect the gastric mucosa from irritating active substances. But the preparation of an oral solution of the active substance may be a better alternative. 

Citrate (1.6 g) and potassium cyanide (520 mg) were added to a mixture of dichloro-methane (10 mL) and water (2.5 mL) that was stirring at 0 °C. The solution was allowed to mix for an additional 15 min and the organic layer which now contained HCN was removed for use as the reaction medium. The mixmre was prepared in a chemical fume hood with the use of a cyanide detector to measure for any release of cyanide vapor. 

The most unstable form of the amorphous variety is colloidal silver, prepared by reduction of an ammoniacal or dilute alcoholic solution of silver nitrate with sodium citrate, sodium potassium tartrate, dextrin, tannin, or formaldehyde, with subsequent addition of ferrous sulphate.13 If forms a chocolate, pale-lilac, blue, or green mass, and dissolves in water to a deep-red solution. The colour depends partly on the mode of... 

Diehl himself worked in the furnace room, a one-floor building on the northern end of the grounds. There he prepared mercuric substances, including corrosive sublimate (mercuric chloride) silver nitrate heavy oil of wine (ethereal oil) solution of chlorinated soda (Labarraque s solution) potassium carbonate potassium acetate citrate of iron and quinine, of which immense quantities were in constant requisition various ferric (iron) solutions syrup of squills and a few other items. He concluded with the following summary ... 

See American Patent, 1077462 Baiziss and Qavion, J. Amer. Ghem. Soe., 1921, 43. 583 Christiansen, ibid., 1922, 44, 2340 Fonmeau, Tr4 ouel, and B6noit, BuU. 80c. ehim., 1927, [iv.], 41, 499. Stable solutions of bismuth salts of this derivative or similar arylarsinic acids are prepared by the addition of a base such as piperazine, or sodium ctr ammonium hydromde, to a susmnsion of the salt, to render it soluble, and of a salt of an aliphatic hydroxypolybasio aciA such as potassium tartrate or citrate—British Patent, 277774 (1926) French Patent, 632834, See British Patent, 264797 (1926). 

Buffer 2, 50 mM Sodium Tartrate in 50 mM Sodium citrate buffer, pH 4.8. Prepare the following solutions. Solution C Dissolve 7.35 g Sodium citrate dihydrate (C6H5Nas07-2H20, FW 294.1 g/mol) and 7.05 g potassium sodium tartrate tetrahydrate (C4H4KNa06-4H20, FW 282.23 g/mol) in... 

Potassium dihydrogen citrate 0.05 molal solution (pH=3.776 at 25 °C) is used for calibration purposes because it exhibits better stability than primary pH reference buffer solutions of tartrate or phthalate [44, 45]. The saline sodium citrate buffer (SSC) prepared from tri-sodium citrate and sodium chloride (pH=7.0) is applied in biochemistry. Citric buffers with different HjCit Na3Cit ratios are clinically effective, for example in reducing gastric acidity [46-48]. Compositions of buffers and corresponding pH values are presented in Table 3.7. 

The chemical operations described in the literature to introduce or into citric acid molecule are based essentially on the Grimaux and Adam synthesis. Labeled citric acid was prepared by Wilcox et al. [35] in the reaction of Na CN with 3-chloro-2-carboxy-2-hydroxybutyric acid and the formed nitrile was hydrolyzed directly with hydrochloric acid. From this solution, citric acid was isolated in the form of calcium citrate and finally converted to the acid. An alternative procedme was proposed by Rothchild and Fields [36] to obtain trimethyl citrate from labeled sodium cyanide and di-chloromethyl glycolate. A more complex synthesis of C labeled citric acid is described by Winkel et al. [39]. They used labeled methyl acetate and acetyl chloride (in the presence of hthium 1,1,1,3,3,3,-hexamethyldisilazide, [(CH3)2Si]2NLi which was dissolved in tetrahydiofuran) to obtain methyl acetoac-etate. It reacts in the presence of lithium diisopropylamide, [(CH3)2CH]2NLi, also dissolved in tetrahydrofuran, with dimethyl carbonate to give dimethyl 1,3-ace-tonedicaiboxylate. It is dicarboxylated by the action of bisulfite and potassium cyanide is converted to 3-cyano-3-hydroxy-l,5 pentanedioate and finally hydrolyzed by hydrochloric acid to citric acid. 

---