Cat.No. Product Name CAS Inquiry
PE-0331 Allylpalladium(II) Chloride Dimer Inquiry
PE-0334 Carbonlychloro bis-(triphenylphosphine)iridium(I) 14871-4-1 Inquiry
PE-0336 Chloro(2-dicyclohexylphosphino-3,6-dimethoxy-2',4',6'-tri-i-propyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium(II) 1451002-39-3 Inquiry
PE-0335 Chlorotris(triphenylphosphine)rhodium(I) 4694-95-2 Inquiry
PE-0332 Dichloro[bis(1,2-diphenylphosphino)ethane]palladium(II) Inquiry
PE-0333 Palladium(II) Acetate Trimer Inquiry
PE-0330 Platinum Carbon (Pt / C) Inquiry
PE-0667 Tetraphenylphosphonium bromide 2751-90-8 Inquiry
PE-0666 Triphenylphosphine 603-35-0 Inquiry

About Catalysis

A catalyst is a substance that influences the rate of a reaction without itself being consumed. A positive catalyst promotes a reaction while a negative catalyst demotes a reaction. Catalysis occurs by changing the activation energy of a reaction but not changing the thermodynamic nature of the reaction. A catalyst can only influence the rate, but not the equilibrium of the reaction. In some cases, a reaction product can catalyze the rate, which is often termed as autocatalysis. The free-radical initiated oxidation certainly is such an example. Hydrogen ions and/or hydroxyl ions are often involved directly in the degradation of pharmaceuticals. When the concentration of hydrogen ion or hydroxyl ion appears in the rate equation, the reaction is said to be subject to specific acid-base catalysis. Drug degradations are often determined in buffered solutions and studied by monitoring the drug itself. As a result, the degradation kinetics is often apparent first-order with the apparent rate constant in the following form:

About Catalysis

For a reaction subject to specific acid catalysis, a plot of the logarithm of the apparent first-order rate constant with respect to pH gives a straight line of slope of 1, while a specific base catalysis generates a straight line of slope of +1. When both are present, a V or U -shaped pH-rate profile is often observed.

General acid-base catalysis occurs when the buffering components catalyze a reaction. Either the acidic or basic components of the buffer, or both, can catalyze a reaction. General acid-base catalysis often causes deviation of the rate-pH profile from the expected unit slopes.

pH-rate profile of hydrolysis of aspirinFig.1 pH-rate profile of hydrolysis of aspirin.

CD Formulation is a leading manufacturer of excipients, serving the pharmaceutical industry to help it improve the performance of its products. We develop, produce and sell pharmaceutical excipients for solid, semi-solid and liquid dosage forms. We can provide pre-formulation, formulation, analysis and customized pharmaceutical excipients services to meet customer needs and formulation challenges. If you have any requirements for excipients, please contact us by phone or email, and our colleagues will reply to you within 2-4 working days.


  1. Garrett, E. R. Prediction of Stability in Pharmaceutical Preparations. IV. The Interdependence of Solubility and Rate in Saturated Solutions of Acylsalicylates. J Am Pharm Ass 1957, 46, 584-586.
  2. Mitsuhiro, and Arisawa. Development of Metal Nanoparticle Catalysis toward Drug Discovery. Chemical and Pharmaceutical Bulletin, 2019, 67(8):733-771.
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