Lactic Acid (CAS 50-21-5)

Vavouli, Charitomeni, et al. Journal of cosmetic dermatology, 2013, 12(3), 204-209.

This work evaluated the efficacy of 3.75% trichloroacetic acid (TCA) combined with 15% lactic acid (LA) for improving periorbital pigmentation. The results showed that this combination peel can enhance depth without the use of high concentrations of agents, and it does not have the potential adverse effects of scarring and permanent depigmentation.
Evaluation methods and results
· A combination of peeling agents containing 3.75% TCA and 15% LA was applied following standard guidelines for chemical peels. The study included thirty patients with periorbital dark circles and skin types II, III, or IV. The chemical peeling treatment was administered weekly for a total of four sessions, with the results documented through photography and assessed by both the patients and physicians.
· The majority of patients experienced a significant improvement in aesthetics, with physicians noting a fair, good, or excellent enhancement in 93.3% of cases. Patients themselves reported a fair, good, or excellent response in 96.7% of cases. The treatment only caused mild and temporary adverse effects, such as erythema, edema, frosting, dryness, and telangiectasias. The effects of the treatment lasted for at least 4-6 months in most patients who used appropriate sun protection.

Madni, Ahmed, et al. International Journal of Polymer Science, 2019, 1, 4362395.

With glycerol and polyethylene glycol (PEG) as reinforcing components, a complete chitosan-vitamin C-lactic acid composite membrane was developed, which synergizes the key properties of each individual component for potential skin tissue engineering. This work preliminarily verified that the prepared membrane exhibited good biocompatibility with fibroblast NIH 3T3 cells.
Preparation procedure of porous chitosan-based composite membranes
· Chitosan membranes with high porosity were created using the freeze-gelation method.
· Initially, a 2% chitosan solution was prepared in a 1% lactic acid solution for a 100 ml solution. The mixture was then placed in a shaking incubator at 30°C and 200 rpm for 24 hours.
· Subsequently, the solution was poured onto petri dishes and frozen at -80°C for 12 hours. The frozen membranes were then treated with a 100 ml solution containing 30 ml of NaOH and 70 ml of ethanol. Following this, the membranes were placed at -20°C for another 12 hours. Afterward, the membranes were rinsed with ethanol and phosphate-buffered saline. They were then lyophilized and stored at 4°C for future use.
· To create porous chitosan composites in a 100 ml solution, the same procedure was followed with some modifications. During the mixing of the chitosan-lactic acid solution, vitamin C (1 g), glycerol (5 ml), and PEG (5 ml) were added.