N-Acetyl-cysteine Increases Chemical Stability of Hydroquinone in Pharmaceutical Formulations: a Theoretical and Experimental Approach

Borges, Rosivaldo S.; Costa, F.M.; Pereira, Tiago L.; Araújo, Rutênio Luiz Castro de; Almeida, Eduardo D.; Silva, Albérico Borges Ferreira da

doi:10.21577/0103-5053.20170174

Cited by 8 publications

(10 citation statements)

References 33 publications

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“…In particular, the mixture of citrate buffer solution (pH 5.5) + PEG 200 (80:20 v / v ) was proposed, as it was able to easily dissolve high RSV concentrations (1 mg/mL). To evaluate the usefulness of the proposed mixture, RSV stability studies were performed both with and without NAC, which is used as a preservative agent for polyphenols [ 40 ]. Stability studies were performed in the dark for 6 h at 37 ± 0.5 °C and the amount of RSV in each sample was quantified by both UV-Vis as well as HPLC analyses.…”

Section: Resultsmentioning

confidence: 99%

Improvement of Resveratrol Permeation through Sublingual Mucosa: Chemical Permeation Enhancers versus Spray Drying Technique to Obtain Fast-Disintegrating Sublingual Mini-Tablets

et al. 2021

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Resveratrol (RSV) is a natural polyphenol with several interesting broad-spectrum pharmacological properties. However, it is characterized by poor oral bioavailability, extensive first-pass effect metabolism and low stability. Indeed, RSV could benefit from the advantage of the sublingual route of administration. In this view, RSV attitudes to crossing the porcine sublingual mucosa were evaluated and promoted both by six different chemical permeation enhancers (CPEs) as well as by preparing four innovative fast-disintegrating sublingual mini-tablets by spray drying followed by direct compression. Since RSV by itself exhibits a low permeation aptitude, this could be significantly enhanced by the use of CPEs as well as by embedding RSV in a spray-dried powder to be compressed in order to prepare fast-disintegrating mini-tablets. The most promising observed CPEs (menthol, lysine and urea) were then inserted into the most promising spray-dried excipients’ compositions (RSV-B and RSV-C), thus preparing CPE-loaded mini-tablets. However, this procedure leads to unsatisfactory results which preclude the possibility of merging the two proposed approaches. Finally, the best spray-dried composition (RSV-B) was further evaluated by SEM, FTIR, XRD and disintegration as well as dissolution behavior to prove its effectiveness as a sublingual fast-disintegrating formulation.

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Section: Resultsmentioning

confidence: 99%

Improvement of Resveratrol Permeation through Sublingual Mucosa: Chemical Permeation Enhancers versus Spray Drying Technique to Obtain Fast-Disintegrating Sublingual Mini-Tablets

et al. 2021

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“…According to these results, the 3,4-dihydro-furan-2-one system (5) is the most important and essential group for the antioxidant effect observed in ascorbic acid [30][31][32][33]. Consequently, similar structures that can be more potent than ascorbic acid in free radicals scavenging were proposed through molecular modifications [24,27] that included: i) the molecular simplification by removal of primary and secondary alcohol from the saturated chain, ii) the removal of carbonyl for the formation of the ether in simplified ring (6), iii) the addition of a second carbonyl in the δ position for the formation of the anhydride derivative (7), and the modification of the lactone group to obtain an aliphatic (8) and olefinic ketone (9).…”

Section: Ho O Oh Ho O Homentioning

confidence: 99%

Essential features for antioxidant capacity of ascorbic acid (vitamin C)

et al. 2021

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Vitamin C or ascorbic acid is an indispensable micronutrient for human health found principally on citrus species such as lemon and orange fruits, and vegetables. It was involved in the production of proteins such as collagen. Its biochemical mechanism is related to its antioxidant capacity, however its function at the cellular level is still unclear. Several theoretical studies about antioxidant and redox mechanisms for ascorbic acid were suggested, however no derivative was proposed. Thereby, an electronic study of antioxidant capacity for ascorbic acid derivatives was performed using theoretical chemistry at the DFT/ B3LYP/6-311++(2d,2p) level of theory. Simplified derivatives show that enol hydroxyls are more important than any other functional group. The vicinal enolic hydroxyl on β-position are more important for antioxidant capacity of ascorbic than hydroxyl on -position. According to our molecular modifications, the keto-alkene compound showed the best values when compared to ascorbic acid in some molecular characteristics. New promising structural derivatives related to ascorbic acid can be developed in the future.

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“…3. According to these results, the 3,4-dihydro-furan-2-one system (5) is the most important and essential group for the antioxidant effect observed in ascorbic acid [30][31][32][33]. Consequently, similar structures that can be more potent than ascorbic acid in free radicals scavenging were proposed through molecular modifications [24,27] that included: i) the molecular simplification by removal of primary and secondary alcohol from the saturated chain, ii) the removal of carbonyl for the formation of the ether in simplified ring (6), iii) the addition of a second carbonyl in the δ position for the formation of the anhydride derivative (7), and the modification of the lactone group to obtain an aliphatic (8) and olefinic ketone (9).…”

Section: Resultsmentioning

confidence: 99%

Essential Features for Antioxidant Capacity of Ascorbic Acid (Vitamin C)

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Pacheco

et al. 2021

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Vitamin C or ascorbic acid is an indispensable micronutrient for human health found principally on citrus species such as lemon and orange fruits, and vegetables. It was involved in the production of proteins such as collagen. Its biochemical mechanism is related to its antioxidant capacity, however its function at the cellular level is still unclear. Several theoretical studies about antioxidant and redox mechanisms for ascorbic acid were suggested, however no derivative was proposed. Thereby, an electronic study of antioxidant capacity for ascorbic acid derivatives was performed using theoretical chemistry at the DFT/ B3LYP/6-311++(2d,2p) level of theory. Simplified derivatives show that enol hydroxyls are more important than any other functional group. The vicinal enolic hydroxyl on β-position are more important for antioxidant capacity of ascorbic than hydroxyl on α-position. According to our molecular modifications, the keto-alkene compound showed the best values when compared to ascorbic acid in some molecular characteristics. New promising structural derivatives related to ascorbic acid can be developed in the future.

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N-Acetyl-cysteine Increases Chemical Stability of Hydroquinone in Pharmaceutical Formulations: a Theoretical and Experimental Approach

Cited by 8 publications

References 33 publications

Improvement of Resveratrol Permeation through Sublingual Mucosa: Chemical Permeation Enhancers versus Spray Drying Technique to Obtain Fast-Disintegrating Sublingual Mini-Tablets

Improvement of Resveratrol Permeation through Sublingual Mucosa: Chemical Permeation Enhancers versus Spray Drying Technique to Obtain Fast-Disintegrating Sublingual Mini-Tablets

Essential features for antioxidant capacity of ascorbic acid (vitamin C)

Essential Features for Antioxidant Capacity of Ascorbic Acid (Vitamin C)

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