• Applied Biological Chemistry
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• v.43 no.1
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• pp.39-45
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• 2000

The stability of vitamin A, $B_1,\;B_2,\;B_6$, C in aqueous multivitamin solutions was carried out by means of estimation of reaction velocity and the results are described in this paper. The stability of vitamin A, $B_1$ and C due to thermal degradation method in aqueous multivitamin solutions was evaluated at 40, 50, 60 and $70^{\circ}C$ up to 40 days. The shelf-lives of vitamin A, B₁ and C in this preparation, calculated using the Arrhenius equation, were 1493, 449 and 639 days at $25^{\circ}C$ respectively. Examination was made on the effect of initial concentration of vitamin $B_2$$(C_0)$ on light fading of vitamin $B_2$ in aqueous multivitamin solutions and it was found that the fading progressed according to the following formula : $-{\frac {dc}{dt}}=K_c\;{\frac C{C_0}}$ where Kc is apparent light-fading rate constant relate to $C_0$. Photodecomposition of vitamin $B_6$ in aqueous multivitamin solutions was apparently first order kinetics and was stable in polyethylene>brown color>glass container to sunlight. Photodecomposition of vitamin $B_6$ in four seasons also investigated.

• YAKHAK HOEJI
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• v.40 no.3
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• pp.243-250
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• 1996

In order to formulate aqueous multivitamin solutions containing both oil-soluble (A, D, E) and water-soluble vitmains ($B_1,\;B_2,\;B_6,\;B_{12}$, C and niacinamide) in 1ml-dose, the effects of various additives such as cosolvents (propylene glycol, polyethylene glycol, glycerin), a sweetener (sorbitol) and a surfactant (Cremophor$^{\circledR}$ RH40) on the solubility of oil-soluble vitamins in water were evaluated. Cremophor$^{\circledR}$ RH40 showed the excellent capacity on the solubilization of oil-soluble vitamins, and the simultaneous addition of cosolvents and surfactant resulted in synergetic effects on the solubilization of oil-soluble vitamins. The effects of the combination of the cosolvents and sweetener on the stability of multivitamin solutions were also evaluated by determining the amount of vitmain A and $B_1$ remained in the solutions after storing at $40^{\circ}C$ for 9 weeks. The formulation consisting of Cremophor$^{\circledR}$ RH40 15%, PG 20%, and sorbitol 20% resulted in the best stability of vitamin A and $B_1$. The stability of vitamin A and $B_1$ in this formulation was evaluated at 50, 60, and $70^{\circ}C$ up to 40 days. The shelf-lives of vitamin A and $B_1$ in the formulation, calculated using the Arrhenius equation, were 1,521 days and 475 days at $20^{\circ}C$, respectively.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.595-601
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• 1997

The optimal synthesis condition based on the yield of thiamine mononitrate has been attained according to Box-wilson experimental design. The optimal condition was as follows : Molar concentration ratio of $SB1{\cdot}HCL=0.6839$, quantity of $NH_4NO_3=50.09g$, agitation velocity=51.6rpm, reaction temperature=22.8$^{\circ}C$. The stabilities of three kinds of thiamine monosalts(thiamine monoiodide, -monobromide, -monorhodanate) were investigated in sterile solution, compressed tablet and multivitamin capsule, respectively. Assay data are given to show that thiamine monosalts are not significantly higher than that of thiamine mononitrate in sterile solutions and the addition of an acidic stabilizer is unnecessary. The solutions were clear and free of precipitate and didn't discolored after storage at room temperature and 40$^{\circ}C$ for 6 months. The tablets and capsules were assayed initially and at predetermined intervals during storage at room temperature and 40$^{\circ}C$ for 6 months. Thiamine monorhodanate was found to be more stable than other thiamine monosalts in these compressed tablets containing other vitamin of the B complex and the data indicate that thiamine monosalts was similar to that of thiamine mononitrate in the multivitamine capsules.