Upon addition of the HCl, a white precipitate formed. The mixture was cooled in an ice bath until a temperature of 10 degrees Celsius was obtained to reduce solubility further. Using vacuum filtration the solid precipitate was extracted from the mixture. To allow the solid precipitate sufficient time to dry mass of the substance was obtained one week later and was found to be 1.
Callum Consultancy Introduction The second article in this series deals with the many constraints that face the pharmaceutical scientist tasked with developing preservation systems for multi-use oral, topical and parenteral medicinal products.
The key role that pH plays in antimicrobial efficacy, as well as general stability considerations both chemical and physicalwill be covered. Evaluating Performance Compendial tests  for antimicrobial efficacy set high performance standards. Activity needs to be broad spectrum, encompassing bacteria Gram-positive and Gram-negativeyeasts, fungi and molds; but not viruses.
An effective preservative must reduce a microbial population significantly and prevent subsequent re-growth and these effects must be both microcidal and microstatic in nature. Combining preservatives that act synergistically may help meet performance standards.
Synergy is also observed in combination with cetrimide, 3-cresol, chlorhexidine and organo mercurials [6,7]. The amino benzoic acid esters parabens are more active against Gram-positive, than Gram-negative bacteria, and more active against yeasts and molds than bacteria.
Parabens also show some synergy with EDTA , 2-phenylethanol  and imidurea . The complexity of multi-phase dermal products, formulated as creams, lotions or ointments mean that adequate microcidal efficacy may not be attainable.
The best that can be achieved is a microstatic effect. In practical terms such performance may be perfectly acceptable. If the bioburden is low most preservative systems can adequately kill or attenuate growth of most organisms.
Current GMP good manufacturing practice standards, encompassing operating and sampling procedures, controls on input materials, use of clean room and automated technologies in manufacturing and packaging, when viewed holistically ensure that high standards of microbial cleanliness can be routinely achieved in fi nished products.
Additionally, the state of the art in packaging technology is now such that contamination, prior to use is unlikely. Hence the risk of contamination is probably greatest during patient use of multi-dose liquid products. In general, microbial growth is optimal between pH Outside this range growth rate signifi cantly declines.
In contrast, the product pH may refl ect the intrinsic pH of the active pharmaceutical ingredient APIor the product may require pH modifi cation to enhance product solubility, stability, palatability or optimal microbial effectiveness MICmax.
Specifi c excipients may also infl uence product pH. Hence, pH adjustment to regions less favorable to microbial viability i. Table 1 lists pH ranges for optimum activity for common preservatives. Such pH effects refl ect the chemical composition of the active moiety in the preservative molecule.
For instance, if activity is associated with the non-ionized moiety acids, alcohols and phenols the effect is usually optimal at acidic pH but ultimately refl ects the pKa of the individual agent. However and almost inevitably, there are exceptions.
|Evaluating Performance||Stomach acid has a pH between 1 and 3 due to the hydrochloric acid content. Based on the net equation given in the book as well as the solubility of the product our hypothesis is that a new substance will form.|
|Introduction||Sodium benzoate was manipulated with HCl until a pH level of two or lower was reached. This mimicked an acidic solution found in the stomach and a white insoluble precipitate was separated and gathered.|
|Received Nov 14; Accepted Apr Yeast growth is a major factor in the spoilage of foods and beverages that are characterized by a high sugar content, low pH, and low water activity, and it is a significant economic problem.|
For example, phenol is most active in acidic solutions, despite its high pKa The consultant’s job was to place the food preservative into a medium that functioned as stomach acid, so sodium benzoate was exposed to an aqueous solution of hydrochloric acid that had a pH range of one to three%(10).
The Effect of pH on a Food Preservative B.
Measuring the Density of an Unknown Liquid. Introduction: The purpose of part a in the experiment was to place sodium benzoate into a medium that simulated stomach acid (pH ) and see whether or not a new substance was formed%(16).
The consultant’s job was to place the food preservative into a medium that functioned as stomach acid, so sodium benzoate was exposed to an aqueous solution of hydrochloric acid that had a 92%(12). Lab 1: Effect of pH on sodium benzoate, a food preservative Sheikh M Zakaria Person no.
TA: Synthia Gratia Date of Submission: 05/29/13 Abstract Sodium Benzoate is a common food preservative used in food products such as jams and jellies, soft drinks, pickles, condiments etc and in tinned products in the market.
Such pH effects refl ect the chemical composition of the active moiety in the preservative molecule. For instance, if activity is associated with the non-ionized moiety (acids, alcohols and phenols) the effect is usually optimal at acidic pH but ultimately refl ects the pKa of the individual agent.
Nov 14, · Microbial spoilage of food causes losses of up to 40% of all food grown for human consumption worldwide. Yeast growth is a major factor in the spoilage of foods and beverages that are characterized by a high sugar content, low pH, and low water activity, and it is a significant economic problem.