Vitamins in Pharmaceutical Formulations

Deritter, E.

doi:10.1002/jps.2600711003

Cited by 91 publications

(61 citation statements)

References 105 publications

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“…B 12 undergoes photolysis to B 12b in aqueous solution which is degraded to irreversible oxidation products (6)(7)(8)(9)(10)(11). Similar reactions occur on the chemical degradation of B 12 and B 12b in the presence of ascorbic acid (AH 2 ) (12)(13)(14) and may be expressed as follows: The effect of thiamine (15,16), nicotinamide (17,18), and riboflavin (19)(20)(21)(22) on the photolysis of B 12 and B 12b has been investigated. Several studies have been conducted on the incompatibility and interaction of B 12 and AH 2 that lead to the loss of B 12 in aqueous solution (12,13,(23)(24)(25)(26)(27).…”

Section: Introductionmentioning

confidence: 99%

“…It is necessary to ascertain the role of AH 2 in the degradation of B 12 and of its degradation product, B 12b , together with that of B 12b alone. AH 2 is oxidized to dehydroascorbic acid (A) (12,14,38) in these reactions. The present work is based on a kinetic study of the comparison of degradation of B 12 and B 12b in the presence of AH 2 over a wide range of pH (1.0-8.0), that covers the pH range employed for the formulation of vitamin preparations.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

et al. 2014

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Abstract. The degradation kinetics of 5×10−5 M cyanocobalamin (B 12 ) and hydroxocobalamin (B 12b ) in the presence of ascorbic acid (AH 2 ) was studied in the pH range of 1. , respectively, indicating a greater effect of AH 2 on B 12b compared to that of B 12 . The k obs -pH profiles for both B 12 and B 12b show the highest rates of degradation around pH 5. The degradation of B 12 and B 12b by AH 2 is affected by the catalytic effect of phosphate ions on the oxidation of AH 2 in the pH range 6.0-8.0.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

et al. 2014

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“…[18][19][20][21] Another approach to achieve stabilization of drugs is through complexation with caffeine and other agents. [22][23][24][25][26] Riboflavin is known to form molecular complexes with caffeine [27][28][29][30][31][32] which has been found to influence the rate of its chemical 33) and photochemical degradation. 17) Riboflavin-caffeine complexation may improve the bioavailability 34) and therapeutic activity 35) of the vitamin.…”

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confidence: 99%

Effect of Caffeine Complexation on the Photolysis of Riboflavin in Aqueous Solution: A Kinetic Study

Ahmad

Ahmed

Sheraz

et al. 2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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1363Riboflavin is a highly photosensitive compound and is degraded in aqueous solution by several mechanisms [1][2][3] including intramolecular photoreduction 4,5) and intramolecular photoaddition. [6][7][8][9] These reactions are affected by pH, 4,5,[10][11][12] solvent polarity and viscosity, 13,14) ionic strength, 15) buffer kind and concentration [6][7][8][9]16) and light intensity and wavelengths. [6][7][8][9]17) Various methods including the use of photostabilizers, incorporation into liposomes and cyclodextrin complexation have been used to stabilize riboflavin solutions in the presence of light. [18][19][20][21] Another approach to achieve stabilization of drugs is through complexation with caffeine and other agents. [22][23][24][25][26] Riboflavin is known to form molecular complexes with caffeine [27][28][29][30][31][32] which has been found to influence the rate of its chemical 33) and photochemical degradation.17) Riboflavin-caffeine complexation may improve the bioavailability 34) and therapeutic activity 35) of the vitamin. NMR studies have been conducted to understand the nature of association between caffeine and flavin mononucleotide 36) that may help in the understanding of the mode of riboflavin stabilization. The present work is based on a detailed study of the kinetics of riboflavin photolysis in the presence of caffeine over a wide range of pH using a specific multicomponent spectrophotometric method 12) for the determination of riboflavin and photoproducts. The kinetic data have been used to determine the stability constants for riboflavin-caffeine complex. The quantitative and kinetic evaluation of such interactions may suggest the possibility of achieving the stabilization of photolabile compounds and thus enhance their biological action. The chemical structures of riboflavin, its photoproducts and caffeine are shown in Fig. 1. ExperimentalThe materials and methods used are the same as previously described for a similar study.5) The photolysis of 5ϫ10 Ϫ5 M riboflavin (RF) solutions was carried out in the presence of 0.5-2.5ϫ10Ϫ4 M caffeine using a Philips HPLN 125 W high pressure mercury vapor fluorescent lamp (emission at 405 and 435 nm) 9) as the irradiation source. The spectral measurements on RF and degraded solutions were performed on a Shimadzu UV-1601 recording spectrophotometer using silica cells of 10 mm path length. The intensity of the fluorescent lamp was determined by potassium ferrioxalate actinome- The effect of caffeine complexation with riboflavin on the kinetics of riboflavin photolysis in the pH range 2.0-10.5 has been studied. The photolysis of riboflavin solutions (5؋10 ؊ ؊5 M) was carried out in the presence of caffeine (0.5-2.5؋10 ؊ ؊4 M) using a visible radiation source. A specific multicomponent spectrophotometric method was used for the determination of riboflavin and photoproducts in photolysed solutions. The apparent first-order rate constants (k) for the photolysis reactions range from 2.71؋10 ؊4 to 4.26؋10 ؊2 min Effect of Caffeine Complexation on the Photol...

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“…20) In the development of sugar-coated tablets containing vitamins, we investigate the relationship between ERH and the stability of vitamins. In this study, ERH of sugar-coated tablets must be lower than 55% for the achievement of stabilized vitamins.…”

Section: Effect Of Erh On Impact Toughness Of Sugar-coated Tabletsmentioning

confidence: 99%

Effect of Moisture on Impact Toughness of Sugar-Coated Tablets Manufactured by the Dusting Method

Ohmori

Ohno

Makino

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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Moisture is one of the most important factors for clarifying the characteristics of solid dosage forms in the pharmaceutical field. There have been a number of reports regarding the effects of moisture on physicochemical properties such as stability of drugs, 1) compactibility of drugs and excipients, 2,3) friability of tablets, 4) and amorphous-to-crystalline transformation 5,6) in solid dosage forms. Moisture in solid dosage forms has attracted much interest over the last decade. Much research is currently in progress.Moisture in solid dosage forms is generally classified into mobile and immobile water.1,7-9) The measurement of mobile water is expressed by water activity or equilibrium relative humidity (ERH). The water activity of a substance is defined as the ratio of the vapor pressure of water due to the substance to the vapor pressure of pure water at the same temperature. ERH is water activity expressed as a percentage.9) Since the amount of mobile water is critical to physicochemical properties on tablets and ERH is easy to measure, we used ERH as a parameter of moisture content in tablets in this study.In our previous work, 10) we proposed a new dusting method for improvement of impact toughness of sugarcoated tablets. The new dusting method uses a dusting powder containing microcrystalline cellulose (MCC). There have been a number of reports regarding the effect of moisture on MCC properties and the moisture sorption and desorption of MCC. [11][12][13][14] Fielden et al. reported that MCC was capable of physically retaining a high percentage of water within itself, while also allowing easy removal by evaporation.11) Suzuki et al. reported that the physical structure of MCC changed during the wet granulation process, and the interaction between MCC and water was gradually strengthened.12) Moisture thus affects the physical properties of MCC.Although there have been several reports regarding the relationship between moisture and color change on sugarcoated tablets, 15-17) the effect of moisture on impact toughness of sugar-coated tablets has not been sufficiently clarified. Above all, the effect of moisture on impact toughness of sugar-coated tablets with MCC has not been sufficiently clarified. Therefore, the purpose of this study was to clarify the effect of moisture on the impact toughness of sugar-coated tablets manufactured by the dusting method. Furthermore, we conducted a free fall test for evaluation of impact toughness of sugar-coated tablets with low moisture content manufactured by the dusting method using dusting powder with or without MCC. We also investigated the relationship between the friability test and the free fall test. ExperimentalMaterials Core tablets containing fursultiamine hydrochloride, vitamin B 6 , vitamin B 12 . vitamin E were used. The weight, diameter, radius of curvature and thickness of core tablets were 180 mg, 8 mm, 6.5 mm, 4.25 mm, respectively. Sucrose (Ensuiko Sugar Refining Co.), talc (Matsumura Sangyo Co.), precipitated calcium carbonate (Nitto Funka Kougyo Co.)...

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Vitamins in Pharmaceutical Formulations

Cited by 91 publications

References 105 publications

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

Effect of Ascorbic Acid on the Degradation of Cyanocobalamin and Hydroxocobalamin in Aqueous Solution: A Kinetic Study

Effect of Caffeine Complexation on the Photolysis of Riboflavin in Aqueous Solution: A Kinetic Study

Effect of Moisture on Impact Toughness of Sugar-Coated Tablets Manufactured by the Dusting Method

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