Influence of Uric Acid on Photostability of Sulfathiazole Sodium Solutions

The effect of uric acid as a photoprotective agent for buffered and unbuffered solutions of sulfathiazole sodium was investigated. Uric acid solution in glycerin was found to enhance the photostability of sulfathiazole sodium solutions. The higher the concentration of uric acid used, the greater was its photoprotective action within the concentration range studied. Uric acid was also found to demonstrate its photoprotective effect in the presence of either sodium sulfite or EDTA. Sodium sulfite alone in a concentration of 0.1% produced a detrimental effect on the photostability of sulfathiazole sodium in either borate or phosphate buffer of pH 9 ± 0.2. From the standpoint of the overall chemical stability of sodium sulfathiazole, uric acid appeared to be most effective when used alone in the borate buffer. However, the incorporation of 0.1% sodium sulfite in addition to uric acid contributed to the prevention of discoloration in either the borate or the phosphate buffer.     

Influence of Uric Acid on Photostability of Fd& C Blue no. 2

The effect of uric acid as a photoprotective agent for various solutions of FD&C Blue No. 2 was investivated. Due to the poor aqueous solubility of uric acid, solutions were made in glycerin, triethanolamine and N/5 NaOH. Uric acid in glycerin or triethanolamine was found to enhance the photostability of the dye solutions. The higher the concentration of uric acid in triethanolamine, the greater was the photoprotective action of uric acid. Increasing the amount of glycerin in solution resulted in acceleration of the rate of fading of the color presumably due to dielectric constant effect. The photoprotective action of uric acid was found to be influenced by the pH of the medium and its buffer species.     

Influence of Certain Additives on the Photostabilizing Effect of Uric Acid for Solutions of Fd&c Blue No. 2

The influence of certain pharmaceutical materials on the photostabilizing effect of uric acid for solutions of FD&C Blue No.2 was investigated. Uric acid in a concentration of 2.5 mg % was found to excercise its effect as a photoprotective agent in presence of DL-methionine, DL-leucine, Tween 80, lactose, sodium benzoate and methyl-paraben. These materials were noted to accelerate the rate of fading of the dye solutions. On the other hand, uric acid appeared to be practically ineffective in presence of sodium edetate and tartaric acid, Uric acid demonstrated the greatest photoprotective action in presence of sodium benzoate or methylparaben.     

Influence of Certain Additives on the Photostabilizing Effect of Uric Acid for Solutions of Fd&c Blue No. 2

The influence of certain pharmaceutical materials on the photostabilizing effect of uric acid for solutions of FD&C Blue No.2 was investigated. Uric acid in a concentration of 2.5 mg % was found to excercise its effect as a photoprotective agent in presence of DL-methionine, DL-leucine, Tween 80, lactose, sodium benzoate and methyl-paraben. These materials were noted to accelerate the rate of fading of the dye solutions. On the other hand, uric acid appeared to be practically ineffective in presence of sodium edetate and tartaric acid, Uric acid demonstrated the greatest photoprotective action in presence of sodium benzoate or methylparaben.     

Influence of DL-Methionine on the Photostability of Ascorbic Acid Solutions

Abstract

The photostablizing effect of DL-methionine for various buffered solutions of ascrobic acid was investigated. DL-methionine in a concentration of 10 mg% was found to enhance the photostability of 40 mg% ascorbic acid in acetate and phosphate buffers, but not in citrate buffer of pH 4.5. The photoprotective action of DL-methionine appeared to be influenced by its concentration, the pH of the medium and its buffer species. DL-methionine was also found to demonstrate its photoprotective action in presence of glycerin, EDTA and Tween 80. PEG 300, however, appeared to have a detrimental effect on the photostabilizing action of DL-methionine for ascorbic acid in acetate buffer of pH 4.5     

Influence of Thiourea on the Photostability of FD & C Red No. 3 Solutions

Abstract

The effect of thiourea as a photostabillzlng agent for FD & C Red No. 3 solutions was investigated. Thiourea was found to enhance the stability of the dye solutions prepared in phosphate buffers of pH values of 7 and 7.9 and exposed to long-wave or short-wave ultraviolet light sources. Thiourea also demonstrated a photoprotective action for the dye solution in phosphate buffer of pH 7 on exposure to fluorescent light. However, thiourea was detrimental to the photostability of the dye solutions prepared in distilled water, acetate, phophate or citrate buffer of pH A.5 and exposed to long-wave or short-wave ultraviolet light sources. The pH of the solution, its buffer species and the concentration of thiourea appeared to influence the photo-stability of FD & C Red No. 3.     

Dimethyl sulfoxide as a photoprotective agent for sodium nitroprusside solutions

Abstract

The effect of dimethyl sulfoxide (DMSO) as a photo-protective agent for various buffered solutions of sodium nitroprusside was investigated. DMSO was found to enhance the photostability of 50 mg% solutions of sodium nitroprusside. In general, the higher the concentration of DMSO, the greater was its photostabilizing effect. However, a 10% v/v of DMSO appeared to be an optimum concentration when acetate buffer of pH 4.65 was used as the solvent medium. The photoprotective action of dimethyl sulfoxide was found to be influenced by the pH of the medium and its buffer species.     

Influence of Certain Additives on the Photostabilizing Effect of Dimethyl Sulfoxide for Sodium Nitroprusside Solutions

Abstract

The influence of certain pharmaceutical adjuvants on the photostabilizing effect of dimethyl sulfoxide for a buffered solution of sodium nitroprusside was investigated. Dimethyl sulfoxide in a concentration of 10% v/v was found to exercise its effect as a photoprotective agent in the presence of methylparaben, sodium sulfite, sodium chloride, destrose, PEG 300, Tween 80, citric acid and sodium edetate. In the absence of dimethyl sulfoxide, sodium sulfite produced the most deleterious effect on the photostability of sodium nitroprusside solution. The photoprotective action of dimethyl sulfoxide appeared to be slightly enhanced by the presence of sodium edetate, methylparaben, sodium chloride or citric acid.     

Influence of Thiourea on the Photostability of FD & C Red No. 3 Solutions

The effect of thiourea as a photostabillzlng agent for FD & C Red No. 3 solutions was investigated. Thiourea was found to enhance the stability of the dye solutions prepared in phosphate buffers of pH values of 7 and 7.9 and exposed to long-wave or short-wave ultraviolet light sources. Thiourea also demonstrated a photoprotective action for the dye solution in phosphate buffer of pH 7 on exposure to fluorescent light. However, thiourea was detrimental to the photostability of the dye solutions prepared in distilled water, acetate, phophate or citrate buffer of pH A.5 and exposed to long-wave or short-wave ultraviolet light sources. The pH of the solution, its buffer species and the concentration of thiourea appeared to influence the photo-stability of FD & C Red No. 3.     

Photoprotective Effect of Dimethyl Sulfoxide for Fd & C Red no. 3 Solutions

Abstract

The effect of dimethyl sulfoxide as a photoprotective agent for various solutions of FD & C Red No. 3 was investi gated. Dimethyl sulfoxide (DMSO) was found to enhance the photostability of the dye solutions when exposed to fluorescent long-wave ultraviolet or short-wave ultraviolet light sources. Fluorescent light was more detrimental to the stability of the dye solutions than any of the other two light sources. The higher the concentration of DMSO, the greater was its photoprotective action within the concentration range studied. The pH of the solution did not appear to influence the photostability of the dye in the presence of DMSO. However, among the buffer species studied, the citrate ions slightly reduced the photoprotective action of DMSO.     

Effect of Certain Stabilizers on Photobleacing of Riboflavin Solutions

Abstract

The influence of certain stabilizers on the aerobic photobleaching of buffered riboflavin phosphate solutions exuosed to fluorescent light was investigated. Disodium ethylenediamine (EDTA) demonstrated the greatest stabilizing effect followed by thiourea, methyl paraben, DL-methionine and sodium thiosul fate. The photostabilizing effect of these agents increased as their concentrations increased. Other stabilizers enhanced the photostability of riboflavin solutions with lesser and varying degrees. The pH and buffer species of the solutions appared to infulence the rate of photodegradation of riboflavin solutions in the presence of absence of EDTA.     

Dimethyl sulfoxide as a photoprotective agent for sodium nitroprusside solutions

The effect of dimethyl sulfoxide (DMSO) as a photo-protective agent for various buffered solutions of sodium nitroprusside was investigated. DMSO was found to enhance the photostability of 50 mg% solutions of sodium nitroprusside. In general, the higher the concentration of DMSO, the greater was its photostabilizing effect. However, a 10% v/v of DMSO appeared to be an optimum concentration when acetate buffer of pH 4.65 was used as the solvent medium. The photoprotective action of dimethyl sulfoxide was found to be influenced by the pH of the medium and its buffer species.     

Influence of Certain Additives on the Photostabilizing Effect of Dimethyl Sulfoxide for Sodium Nitroprusside Solutions

The influence of certain pharmaceutical adjuvants on the photostabilizing effect of dimethyl sulfoxide for a buffered solution of sodium nitroprusside was investigated. Dimethyl sulfoxide in a concentration of 10% v/v was found to exercise its effect as a photoprotective agent in the presence of methylparaben, sodium sulfite, sodium chloride, destrose, PEG 300, Tween 80, citric acid and sodium edetate. In the absence of dimethyl sulfoxide, sodium sulfite produced the most deleterious effect on the photostability of sodium nitroprusside solution. The photoprotective action of dimethyl sulfoxide appeared to be slightly enhanced by the presence of sodium edetate, methylparaben, sodium chloride or citric acid.     

Influence of Certain Additives on the Photostability of Colch Icine Solutions

Abstract

The photostability of colchicine solutions in the presence of selected additives under shortwave ultraviolet light was investigated P-aminobenzoic acid (PABA) and uric acid solubilized by lithium carbonate enhanced the photostability of colchicine. Glycerin on the other hand demonstrated a detrimental effect. Buffer species and pH of the vehicle were found to influence the apparent zero-order rate of degradation of colchicine solutions.     

Influence of certain additives on the photostability of colchicine solutions+

Abstract

The photostability of colchicine solutions in the presence of selected additives under shortwave ultraviolet light was investigated. p-aminobenzoic acid (PABA) and uric acid solubilized by lithium carbonate enhanced the photostability of colchicine. Glycerin on the other hand demonstrated a detrimental effect. Buffer species and pH of the vehicle were found to influence the apparent zero-order rate of photodegradation of colchicine solutions.     

Photoprotective Effect of Dimethyl Sulfoxide for Fd & C Red no. 3 Solutions

The effect of dimethyl sulfoxide as a photoprotective agent for various solutions of FD & C Red No. 3 was investi gated. Dimethyl sulfoxide (DMSO) was found to enhance the photostability of the dye solutions when exposed to fluorescent long-wave ultraviolet or short-wave ultraviolet light sources. Fluorescent light was more detrimental to the stability of the dye solutions than any of the other two light sources. The higher the concentration of DMSO, the greater was its photoprotective action within the concentration range studied. The pH of the solution did not appear to influence the photostability of the dye in the presence of DMSO. However, among the buffer species studied, the citrate ions slightly reduced the photoprotective action of DMSO.     

Effect of Certain Stabilizers on Photobleacing of Riboflavin Solutions

The influence of certain stabilizers on the aerobic photobleaching of buffered riboflavin phosphate solutions exuosed to fluorescent light was investigated. Disodium ethylenediamine (EDTA) demonstrated the greatest stabilizing effect followed by thiourea, methyl paraben, DL-methionine and sodium thiosul fate. The photostabilizing effect of these agents increased as their concentrations increased. Other stabilizers enhanced the photostability of riboflavin solutions with lesser and varying degrees. The pH and buffer species of the solutions appared to infulence the rate of photodegradation of riboflavin solutions in the presence of absence of EDTA.     

Influence of certain additives on the photostability of colchicine solutions+

The photostability of colchicine solutions in the presence of selected additives under shortwave ultraviolet light was investigated. p-aminobenzoic acid (PABA) and uric acid solubilized by lithium carbonate enhanced the photostability of colchicine. Glycerin on the other hand demonstrated a detrimental effect. Buffer species and pH of the vehicle were found to influence the apparent zero-order rate of photodegradation of colchicine solutions.     

Influence of Certain Additives on the Photostability of Colch Icine Solutions

The photostability of colchicine solutions in the presence of selected additives under shortwave ultraviolet light was investigated P-aminobenzoic acid (PABA) and uric acid solubilized by lithium carbonate enhanced the photostability of colchicine . Glycerin on the other hand demonstrated a detrimental effect . Buffer species and pH of the vehicle were found to influence the apparent zero-order rate of degradation of colchicine solutions.     

Photostabilization of Demeclocycline Hydrochloride with Reduced Glutathione

Photodegradation of demeclocycline hydrochloride (DCL) in buffer solutions was studied in absence and presence of some potential photostabilizers under the influence of fluorescent light. Photolysis of DCL solutions followed first-order kinetics, DCL was more stable in acidic pH. Change in ionic strength of the buffer had no effect on the photolysis of DCL. Among the potential photostabilizers tested, reduced glutathione (GTH) was found to be the most effective photoprotective agent. Increase in GTH concentration decreased the photodegradation rate, but this decrease was not significant above 20 μg/ml GTH concentration. The photodegradation of DCL both in presence or absence of GTH was lowest at pH 4.5 citrate buffer, compared to acetate or phosphate buffer. A mixture of 50% (v/v) propylene glycol or 50% (v/v) PEG 400 in phosphate buffer did not demonstrate any photostabilizing effect. Aluminum foil-covered glass vials provided greater photoprotection compared to clear glass or amber glass vials.