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Development of Ophthalmic Formulations
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Paramita Sarkar, Martin Coffey, Mohannad Shawer
Antimicrobial acids have a useful pH range around the pKa of the acid, and the optimal antimicrobial activity will typically occur very close to this pKa. The most commonly used acid for the preservation of ophthalmic formulations is sorbic acid (or potassium sorbate), which has a pKa of 4.76. Sorbic acid is primarily antifungal, but it does have antibacterial activity. Sorbic acid is useful in the pH range of 4.5–6 and is usually combined with EDTA or other preservatives for broad-spectrum preservation. Sorbic acid is sensitive to oxidation, which results in discoloration of the product, and is more rapidly degraded at temperatures above 38°C. Boric acid is another useful acid for preservation in ophthalmic formulations; however, its activity is classified as bacteriostatic rather than biocidal.
Sustainable plant-based bioactive materials for functional printed textiles
Published in The Journal of The Textile Institute, 2021
Alka Madhukar Thakker, Danmei Sun
Shaw further investigated that traditionally vegetable oil, glycol, honey, molasses, or glucose were mixed with gums and starch to refute drying and thus maintain the desired ink viscosity for printing. Preventol (0.5% formaldehyde) was also utilized. Interestingly vegetable sources of preservatives were identified namely, sorbic acid naturally occurring in the fruits of mountain ash. Sorbic acid when neutralized converts to potassium sorbate can also be utilized as a natural preservative. Benzoic acid can be extracted from the fruits of the elder. Salicylic acid is found in olive oil, tea, wine, willow, and myrtle others (Phil, 1999). Thus, an exhaustive literate is available on alternative surplus natural materials for prospective application on textile substrates, however abundant of research experimentation would be obligatory. Also, concurrently we ought to accomplish our responsibility of protecting biodiversity and planting them back in nature to continue the vicious and harmonious cycle of our relationship with nature for a sustainable future.