Fluorescence enhancement reaction of flavoxate hydrochloride (FX) in strong alkali solution was studied, the mechanism of the reaction was investigated, and a novel fluorimetric method for analysis of FX in drug sample was established. FX has no intrinsic fluorescence, but it can slowly produce fluorescence in strong alkali solution. Heating can promote the fluorescence enhancement reaction. In 3D fluorescence spectra of the decomposition product of FX, two fluorescence peaks, located respectively at excitation wavelengths λex/ emission wavelength λem =223/410 nm, and 302/410 nm, were observed. Using quinine sulfate as a reference, fluorescence quantum yield of the decomposition product was measured to be 0.50. The structural characteriza- tion and spectral analysis of the decomposition product reveal that ester bond hydrolysis reaction of FX is firstly occurred during heating process, forming 3-methylflavone-8-carboxylic acid (MFA), then a cleavage reaction of the γ-pyrone ring of MFA occurred, producing α, β-unsaturated ketone. This product includes adjacent hydroxyl benzoic acid group in its molecule, which can form intramolecular hydrogen bond under alkaline condition, so that increase the conjugate degree and enhance the rigidity of the molecule, and thereby cause fluorescence enhancement. Based on this fluorescence enhancement reaction, a fluorimetric method was proposed for the determination of FX. A linear calibration curve covered the concentration range 0.020 3-0.487 µg · mL. The regression equation was I(F) = 23.9 + 5357.3 c, with correlation coefficient r = 0.999 7 (n = 8), detection limit D = 1.1 ng · mL(-1). The method was applied to the analysis of FX tablets, with a spiked recovery rate of 100.2%. The reliability of the method was verified by a UV-spectrophotometric method.
Alkalies ; Calibration ; Chemistry, Pharmaceutical ; Flavoxate ; analogs & derivatives ; chemistry ; Fluorescence ; Limit of Detection ; Reproducibility of Results ; Solutions ; Tablets

OBJECTIVEThe National Institutes of Health (NIH) category IIIa chronic prostatitis syndromes (non bacterial chronic prostatitis) were common disorders but with few effective therapies. Alpha-blockers and bioflavonoids had recently been reported in randomized controlled trials to improve the symptom of these disorders in a significant proportion of men. The aim of this study was to confirm these findings in a prospective randomized, placebo-controlled trial.

METHODSForty-five men with category IIIa chronic non bacterial protatitis were randomized into three groups as follows: (1) placebo; (2) phenoxybenzamine-hydrochloride:10 mg two times a day for one month; (3) flavoxate HCI-neptumus: 200 mg three times a day for one month. The NIH chronic prostatitis symptom score was used to grade symptoms at the beginning and conclusion of the study.

RESULTSAll the patients in three groups completed the study except three dropout patients in placebo group because of sever symptoms. The three groups were similar in age, duration of symptoms and initial symptom score. Patients taking placebo had a mean improvement in NIH-CPSI from 21.85 to 19.55 (not significant), while the phenoxybenzamine-hydrochloride group had a mean improvement from 21.95 to 13.75 (P < 0.01), and those taking flavoxate HCI-neptumus had a mean improvement from 21.75 to 16.95 (P < 0.05). The decrease in NIH-CPSI was associated with significant improvement in patients' clinical manifestations.

CONCLUSIONTherapy with alpha-blockers was well tolerated with significant symptomatic improvement in most men having chronic non-bacterial chronic protatitis while the bioflavonoids group had no significant improvement. Mechanism of both medicines needs further study.

Adrenergic alpha-Antagonists ; administration & dosage ; therapeutic use ; Adult ; Chronic Disease ; Flavonoids ; administration & dosage ; therapeutic use ; Flavoxate ; therapeutic use ; Humans ; Male ; Parasympatholytics ; therapeutic use ; Prospective Studies ; Prostatitis ; drug therapy ; Treatment Outcome