The fate of drotaverine-acephyllinate in rat and man. I. Absorption, distribution and excretion in the rat

The Influence of Oral Drotaverine Administration on Materno–Fetal Circulation during the Second and Third Trimester of Pregnancy

Background and Objectives: The study aimed to evaluate the effect of the oral administration of drotaverine on maternal and fetal circulation as measured by Doppler sonography in women with a risk of preterm birth. Materials and Methods: The present prospective study was conducted on 34 women with singleton pregnancy at 26–36 weeks of gestation. Doppler flow and pulsatility index (PI) assessments of the umbilical artery, fetal middle cerebral artery, and uterine arteries were performed before and 90–120 min after oral drotaverine administration. Results: There were no statistically significant differences between the Doppler assessment (PI Uma—umbilical artery, MCA—middle cerebral artery, and ltUta—left uterine artery) before drotaverine administration and 90–120 min after oral intake, but there were statistically significant differences between the PI assessment of the rtUta (right uterine artery, 0.55 vs. 0.75, p = 0.05) and the mean of the Uta (0.66 vs. 0.74, p = 0.03). For changes in the CUR (cerebro–umbilical ratio) and % changes in the CUR and mean PI of the Uta, there was no correlation with obstetric history, AFI (amniotic fluid index), gestation week, infertility history, systolic pressure, or diastolic pressure. There was a statistically positive correlation between changes in the CUR and % change in the CUR and body weight and in height. Conclusions: Drotaverine has no statistically significant influence on the MCA and Uma PI. The oral administration of drotaverine has an impact on PI rtUta and the mean PI Uta.

Solid-state chemistry of ambroxol theophylline-7-acetate

Ambroxol theophylline-7-acetate (ACE) is the salt obtained by reaction of equimolar amounts of ambroxol (AMB), a drug showing mucolytic and expectorant properties, and theophylline-7-acetic acid (TAA), a xanthine derivative with specific bronchodilator activity. ACE is used for the treatment of bronchial and pulmonary diseases (bronchitis, asthma, emphysema, chronic obstructive disease). Recrystallization experiments of ACE resulted in the isolation of two polymorphs (monotropically related) and four solvated forms. X-ray diffractometry, DSC, TGA, and HSM techniques were used to investigate the forms that are obtained by thermal desolvation of the solvates. The phase diagram of the TAA-AMB binary system was constructed by performing thermal analyses on mixtures of TAA-AMB and of each component plus the interaction compound (TAA-ACE and ACE-AMB). The Schroeder-Van Laar equation proved to be a very useful tool for checking the consistency between the experimental data and the theoretical model related to the general system, showing complete miscibility in the liquid phase and complete immiscibility in the solid phase.

High-performance liquid chromatographic method for the determination of drotaverine in human plasma and urine

A simple and sensitive HPLC method for the determination of drotaverine in human plasma and urine has been developed. Alkalinized plasma or urine was extracted with organic solvent and the basic components in the organic phase were back-extracted into 0.1 M HCl. An aliquot of the aqueous layer was injected onto the column and the eluent was monitored at 254 nm. Separation was performed on a C18-column with 0.02 M sodium dihydrogen phosphate-methanol (30:70, v/v) containing perchlorate ion at pH 3.2 as mobile phase. Drotaverine was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios and plasma concentrations and the intra- and inter-assay coefficients of variation were always < 10%. The lowest limit of detection (signal-to-noise ratio 3:1) was 6 ng/ml. The method is suitable for therapeutic monitoring and pharmacokinetic studies of drotaverine in humans as well as in animal models.

Comparative studies of drotaverine--acephyllinate (Depogen) and pentoxifylline (Trental)

Pentoxifylline is an orally active agent for the treatment of peripherial and cerebral vascular diseases. Pentoxifylline increases the deformability of red blood cells in vitro, reduces blood viscosity and decreases platelet aggregation and thrombus formation. Depogen has shown antiaggregatory effect both in vitro and in ex vivo. The inhibitory effect of Pentoxifylline was about 3-5 times weaker than that of Depogen. IC50 = 900/micrograms/ml for Depogén and 3600/micrograms/ml for Pentoxifylline on human platelet rich plasma. Depogen has shown ex vivo antiaggregatory effect on anesthetised rabbits, ID50 = 7 mg/kg in case of iv. administration, and ID50 = 300 mg/kg in case of orally administration. Both compound inhibit the release of platelet precoagulation factor, but the effect of Pentoxifylline was slighter.