Effect of pH on Pharmaceutical Ingredients / Drugs / Chemicals
DOI:
https://doi.org/10.22270/ajdhs.v2i3.17Keywords:
Solubility, API, Impurity, PhAbstract
The word excipient is derived from the Latin excipere meaning to except, which is simply explained as other than. Pharmaceutical excipients are basically everything other than the active pharmaceutical ingredient. Ideally, excipients should be inert, however, recent reports of adverse reactions have suggested otherwise. Pharmaceutical excipients are substances other than the active pharmaceutical ingredient (API) that have been appropriately evaluated for safety and are intentionally included in a drug delivery system. Solubility, which defines the liquid /solid equilibrium, is a key parameter to control a crystallization process. As the API is a weak acid (pKa = 3.7), its solubility increases with the pH. On the basis of the experimental curve of solubility, a model was defined to fit the evolution of the solubility as a function of pH. In the case of this compound, studies revealed a weak influence of the temperature in comparison with the pH. So, the solubility of the compound is slightly impacted by the temperature. Some experiments were carried out in order to compare the solubility of the API, at the same pH and temperature, for different concentrations of impurities found in the process. The results revealed a solubility increase in presence of acetic acid and a high solubility decrease in presence of sodium chloride. By carrying out experiments on common ions salts, the anion chloride Cl− has been identified as the cause of the solubility decrease.
Keywords: Solubility, API, Impurity, Ph
References
Avdeef A. Solubility of sparingly-soluble ionisable drugs. Advanced drug delivery reviews, 2007; 59:568-590. https://doi.org/10.1016/j.addr.2007.05.008
Carta R. Solubilities of L-cystine, L-tyrosine, L-leucine and glycine in aqueous solutions at various pH and NaCl concentrations. The Journal of Chemical & Engineering Data. 1996; 41:414-417. https://doi.org/10.1021/je9501853
Granberg RA, Rasmuson AC. Solubility of paracetamol in binary and ternary mixtures of water plus acetone plus toluene. The Journal of Chemical & Engineering Data. 2000; 45:478-483. https://doi.org/10.1021/je990272l
Leontidis E. Hofmeister anion effects on surfactant self-assembly and the formation of mesoporous solids, Current Opinion in Colloid & Interface Science. 2002; 7:81-91. https://doi.org/10.1016/S1359-0294(02)00010-9
Published
How to Cite
Issue
Section
Citations
Copyright (c) 2022 Md Amir, Md Ashfaque Alam, Md Fauwaz Aftab, Md Gulam Nabi, Md Sadre Alam, Jagdeesh Rathi, Sonpal Singh Thakur
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.