Pyridoxal.hydrochloride

Pyridoxal hydrochloride, pyridoxamine hydrochloride and pyridoxine hydrochloride (vitamin Bg) see entries in Chapter 6. 

Pyridoxal hydrochloride [65-22-5] M 203.6, m 176-180 (dec), pK 4.23 (3-OH), pK (Pyridinium+), pK 13.04 (CHjOH ). Dissolve in water and adjust the pH to 6 with NaOH. Set aside overnight to crystallise. The crystals are washed with cold water, dried in a vacuum desiccator over P2O5 and stored in a brown bottle at room temperature. [Fleck and Alberty J Phys Chem 66 1678 7962.]... 

T Durig, AR Fassihi. Preformulation study of moisture effect on the physical stability of pyridoxal hydrochloride. Int J Pharm 77 315-319, 1991. 

SYNS 3-HYDROXY-5-(HYDROXYMETHYL)-2-METH-YLISONICOTINALDEHYDE, HYDROCHLORIDE 2-METHYL-3-HYDROXY-4-FORMYL-5-HYDROXYMETH-YLPYRIDINE HYDROCHLORIDE PYRIDOXAL HYDROCHLORIDE... 

Wiley and Irick40 prepared active Mn02 by addition of saturated aqueous potassium permanganate to a hot solution of manganese sulfate monohydrate in 300 ml. of water until the purple color just persisted. The precipitated MnOa was collected and dried, and used in the oxidation of pyridoxine hydrochloride to pyridoxal hydrochloride. 

Polymorphic transitions were observed between two crystalline forms of benoxapro-fen,578 three forms of bromovaleiylurea,579 and two forms of pyridoxal hydrochloride.580 These are just a few examples of the many drug substances exhibiting multiple polymorphic forms. Cianidanol exhibits polymorphic transitions between seven different crystalline forms, depending on temperature and humidity as shown in Scheme 79. However, no difference in dissolution rate was observed among these crystalline forms.581... 

Pyridoxal hydrochloride Vitarrrirr B6 CsHioCINOj 66-22-6 203.623 orth 166 dec vs HgO si EtOH... 

Desmotropy of the Schiff Base of Diethylaminomalonate and Pyridoxal Hydrochloride... 

Intra- and interassay variability for aU analytes ranged from 0.4% to 7.9% and from 2.2% to 5.2%, respectively. Quantification was done by ratio response to the stable isotope-labeled internal standards. C4-Thiamine hydrochloride, 4, N2-riboflavin, and Hj-pyridoxal hydrochloride were added to the samples as internal standards for quantification. The standard addition method determined recovery rates for each vitamin (73.0-100.2%). The limit of quantitation for all vitamins was between 0.05 and 5 [ig/L depending on the vitamin. 

Toxicity. Pyridoxal hydrochloride exhibits oral toxicity (Table 11) at about 2,000 mg/kg body weight (Cimuning et al, 1978). 

Vitamin Solution. Dissolve 0.5 mg. of folic acid and 5 mg. each of p-aminoben-zoic acid, thiamine hydrochloride, pyridoxal hydrochloride, calcium pantothenate, riboflavin, and nicotinic acid in water to make 100 ml. Store imder a preservative in a refrigerator. Prepare a fresh solution every month. 

---