Riboflavin laurate nanosuspensions as an intramuscular injection for long-term riboflavin supplementation.

The aim of this study was to prepare riboflavin laurate (RFL) nanosuspensions as an intramuscular injection for long-term riboflavin supplementation. Stable RFL nanosuspensions were obtained by injecting RFL/poloxamer solution in N,N-dimethyl formamide into a trehalose solution. Long soft nanostructures initially appeared and then tube-like rigid nanostructures were obtained after removal of solvents according to the transmission electron microscopic images. The nanosuspensions had narrow size distribution and the mean size was about 300 nm. Molecular self-assembly of RFL may drive the formation of nanostructures. RFL formed a monolayer at the air/water interface and poloxamer 188 could insert into the monolayer. The nanosuspensions were intramuscularly injected into rats to provide long-term riboflavin supplementation for more than 30 days in light of body weight, food intake, and urinary riboflavin. The nanosuspensions were also used to resist the riboflavin deficiency induced by methotrexate chemotherapy. RFL nanosuspensions are a promising nanomedicine for long-term riboflavin supplementation.

[Metazid-inducible vitamin B2 deficiency in rats and its prevention]. / Metazidindutsiruemaia nedostatochnost' vitamina B2 u krys i ee predotvrashchenie.

Rectal administration of metaside (20 mg per 100 g body weight) as suppositories for 10 days was found to cause vitamin B2 deficiency both in rats on low-vitamin B2 diet and in those on balanced diet. This appeared as decreased vitamin B2 levels in the liver and plasma. The design and application of suppositories containing the mixed preparation of metaside and riboflavin drug (in a dose of 100 micrograms per rat, which corresponds to the recommended daily requirement) completely prevents vitamin B2 deficiency.

Riboflavin deficiency in women taking oral contraceptive agents.

The effect of oral contraceptive agents (OCA) on riboflavin nutritional status of women of child-bearing age in a low socioeconomic population was studied. For a control group, 100 women in the same age and socioeconomic group using alternate forms of contraception were selected. Riboflavin deficiency was determined by measuring erythrocyte glutathione reductase activity, a reliable index of the deficiency. None of the women was on vitamin supplements or had clinical conditions effecting dietary intake or utilization. Eleven of 100 women in the control group had biochemical evidence of deficiency. This compared to 24 of 56 OCA users who were deficient. The frequency of deficiency increased among those on OCA for longer periods of time. Thirteen of 17 OCA users for 3 years or more, compared to 11 of 39 users under 3 years were deficient. There were no discernable dietary differences between the groups. These studies demonstrate that riboflavin deficiency is a problem of women in the lower socioeconomic level in the child-bearing age. The use of OCA aggravates the prevalence of deficiency.

Preventive effect of riboflavin and ATP on the teratogenic effects of the phenothiazine derivative T-82.

To examine the hypothesis that the teratogenic effects of the phenothiazine derivative T-82 are due to its causing a riboflavin deficiency day 11 or 12 pregnant CB Wistar rats were each given 2,000 mg/kg T-82 po plus 100 mg/kg riboflavin ip, 12.4 mg/kg ATP ip, or both. The rates of fetal mortality and external malformations were significantly decreased in all supplementation experiments. The frequencies of cleft palate, micrognathia, and micromelia were unchanged but those of ectopic testis and hydrops fetalis were significantly increased in the group treated with T-82 and ATP on day 12.