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An ultraperformance liquid chromatography–tandem mass spectrometry method was developed for simultaneous determination of seven sulfonylurea-type oral anti-diabetic agents (glipizide, tolbutamide, tolazamide, gliclazide, glibenclamide, glimepiride, and glurenor) in dietary supplements and traditional Chinese medicines. The samples were extracted twice with methanol by ultrasound. The separation was achieved on a C18 column with the mobile phase consisting of acetonitrile and water (0.2% formic acid (v/v) and 5 mM ammonium acetate), at a flow rate of 0.3 mL/min with gradient elution. The analysis time was 8 min per sample. The proposed method was validated for linearity (r > 0.99), precision (relative standard deviation better than 6.0%), recoveries (83–110%), and the limit of detection in the range 0.3–2 µg kg−1. The proposed method is rapid, reliable, sensitive, accurate, and good applicability, and it was successfully applied to analyze 20 real samples of 15 dietary supplements and five traditional Chin...

The oral hypoglycemic sulfonamides carbutamide, chlorpropamide, glibenclamide, glibornuride, gliclazide, glipizide, gliquidone, glisoxepide, glymidine, tolazamide, and tolbutamide were investigated for photohemolytic properties in vitro. Irradiation with a solar simulator revealed hemolysis in the presence of chlorpropamide, glipizide, gliquidone, glymidine, and tolbutamide (all at a concentration of 10−3 mol/L). Except for glymidine, which exerted photohemolysis at the concentration 10−4 mol/L, no hemolytic effects were seen in the concentration of 10−4 mol/L or 10−5 mol/L. Irradiation with light sources emitting mainly ultraviolet B (UVB), ultraviolet A (UVA), or visible light did not induce phototoxic hemolysis with any of the test substances. Tolbutamide and chlorpropamide have previously been described as a cause of clinical photosensitivity, whereas the other drugs so far have not shown phototoxic effects in humans.

The objective of this study is to prepare solid dispersions of tolazamide (TLZ) using polyethylene glycol (PEG) and measure the dissolution of TLZ. PEG 8000 was used as carrier to prepare solid dispersions by melt and solvent methods. Dissolution studies indicated a remarkable increase in the rate of dissolution of TLZ when dispersed in PEG as well as with physical mixture of TLZ and PEG. The rate of dissolution of TLZ was faster with solid dispersions containing TLZ:PEG (1:5) and (1:10) compared to physical mixtures and pure TLZ. The effect of buffer on dissolution was studied. In general the dissolution of TLZ was less in phosphate buffered saline (PBS, pH 7.4) compared to Tris buffer. However, there was no significant difference in the extent of dissolution of TLZ from solid dispersions and physical mixture compared to pure TLZ. Solid dispersions prepared by solvent method showed faster dissolution rates compared to melt method. These results suggest that the rate of dissolution can be increase...

A spectrophotometric method for the determination of some pharmaceutical amides, hydrazides and thiols is described. The method is based on the reaction of the studied drugs with 2,2-diphenyl-1-picryl hydrazyl (DPPH). The latter is employed to abstract a hydrogen atom from the drugs thereby promoting a process of radical coupling. This results in a reduction of the violet colour of DPPH with the formation of the yellow coloured 2,2-diphenyl-1-picrylhydrazine (DPPH2). This fading in colour of DPPH reagent depends on the concentration of the drug being determined. Beer's law is obeyed in the ranges of 1–5 μg/ml (for isocarboxazid and gliclazide), 0.25–2.5 μg/ml (for isoniazid), 0.5–5 μg/ml (for iproniazid), 1–7 μg/ml (for tolazamide), 2–15 μg/ml (for captopril) and 1–6 μg/ml (for sulphathiourea). The validity of the method was tested by analysing the studied drugs in pure form as well as in tablets. Results of analyses were compared statistically with the official or reported methods.

An analytical method is described for the assay of two important oral hypoglycemic agents, namely, glibenclamide (glyburide); and tolazamide; using PMR technique. The method is rapid, accurate, specific and precise. The principle of the method involves comparing the integral of a chosen signal in the PMR spectrum of the drug under investigation with that of the methylene group signal of the internal standard, benzyl benzoate.