Poorly water-soluble drugs, such as phenylephrine, offer challenging problems for buccal drug delivery. In order to overcome these problems, particle size reduction (to the nanometer range) and cyclodextrin complexation were investigated for permeability enhancement. The apparent solubility in water and the buccal permeation of the original phenylephrine coarse powder, a phenylephrine-cyclodext...

We assume that phenylephrine produces late pharmacological preconditioning through the opening of the mitochondrial KATP channels. To test this hypothesis, rat hearts were isolated and perfused with Krebs buffer solution by Langendorff method and subjected to 30 min regional ischemia followed by 60 min of reperfusion. In this study, phenylephrine as a selective alpha1-adrenoceptor agonist and 5...

in this study, different derivative spectrophotometric methods are proposed for the simultaneous determination of chlorpheniramine maleate (cp), phenylephrine hcl (pe) and phenylpropanolamine hcl (pp) in their ternary mixtures and in pharmaceutical dosage forms. spectra of single component and ternary mixtures of various concentrations and combinations from zero- to fourth-derivation were obtai...

Background and objective: Phenylephrine is the first-line choice for prevention and treatment of hypotension during spinal anesthesia for cesarean section. However, the serious bradycardia caused by phenylephrine is a concern. This study compared the effects of prophylactic bolus norepinephrine and phenylephrine on hypotension during spinal anesthesia for cesarean section. Methods: A total of 1...

INTRODUCTION phenylephrine is used daily during anesthesia for treating hypotension. However, the effects of phenylephrine on cardiac output (CO) are not clear. We hypothesized that the impact of phenylephrine on cardiac output is related to preload dependency. METHODS eight pigs were studied at a preload independent stage (after CO augmentation) and at a preload dependent stage (after a 21 m...

In 12-15-day pregnant rat myometrium, spikes of the longitudinal muscle were discharged spontaneously in burst, while the circular muscle had predominantly a plateau potential. In the longitudinal muscle, phenylephrine (10(-7) g/ml) slightly decreased the duration of the burst discharge and suppressed the contraction by beta-adrenoreceptor stimulation. In the circular muscle, phenylephrine (10(...

BACKGROUND In our routine practice, we observed a reduced incidence of fetal acidosis (umbilical artery pH < 7.20) at cesarean delivery during spinal anesthesia when a combination of phenylephrine and ephedrine was used as first line vasopressor therapy, compared with using ephedrine alone. METHODS The study was randomized and double blind. It compared phenylephrine 100 microg/ml (phenylephri...