Search results for "Pyrrolidinone"

Cardiovascular effects induced by rolipram, a selective cAMP phosphodiesterase inhibitor: Interaction with adrenergic and calcium affecting drugs

1990

The transcriptional inhibitor thiolutin blocks mRNA degradation in yeast.

2007

Thiolutin is commonly used as a general inhibitor of transcription in yeast. It has been used to calculate mRNA decay rates by stopping the transcription and then determining the relative abundance of individual mRNAs at different times after inhibition. We report here that thiolutin is also an inhibitor of mRNA degradation, and thus its use can lead to miscalculations of mRNA half-lives. The inhibition of mRNA decay seems to affect the mRNA degradation pathway without impeding poly(A) shortening, given that the decay rate of total poly(A) amount is not reduced by thiolutin. Moreover, the thiolutin-dependent inhibition of mRNA degradation has variable effects on different functional groups …

Bioadhesive monolayer film for the in vitro transdermal delivery of sumatriptan

2006

The work presented here aims to develop a bioadhesive monolayer film containing sumatriptan as adjuvant for the treatment of headache pain in a severe migraine attack. Permeation experiments were performed from the films prepared and from the respective solution, to evaluate the relevant permeation parameters. The effect of the penetration enhancers Transcutol, 2-pyrrolidone, and polyethylene glycol 600 was evaluated. The results obtained show that Transcutol and 2-pyrrolidone decreased sumatriptan permeation from solution, whereas a modest increase was produced by polyethylene glycol 600. The enhancers produced the same effects when they were included in the film. Compared to solution, the…

Comparative Study of Different Methods for the Prediction of Drug–Polymer Solubility

2015

In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid ana…

Influence of Polymer Molecular Weight on Drug–polymer Solubility: A Comparison between Experimentally Determined Solubility in PVP and Prediction Der…

2015

ABSTRACT: In this study, the influence of polymer molecular weight on drug–polymer solubility was investigated using binary systems containing indomethacin (IMC) and polyvinylpyrrolidone (PVP) of different molecular weights. The experimental solubility in PVP, measured using a differential scanning calorimetry annealing method, was compared with the solubility calculated from the solubility of the drug in the liquid analogue N-vinylpyrrolidone (NVP). The experimental solubility of IMC in the low-molecular-weight PVP K12 was not significantly different from that in the higher molecular weight PVPs (K25, K30, and K90). The calculated solubilities derived from the solubility in NVP (0.31–0.32 …

Rolipram inhibits airway microvascular leakage induced by platelet-activating factor, histamine and bradykinin in guinea-pigs.

1993

Abstract Rolipram (0·1–1000 μg kg−1, i.v.) reduced the increase in microvascular permeability induced by platelet-activating factor (PAF; 50 ng kg−1, i.v.) at different sites of the guinea-pig airways. Rolipram (1–100μg kg−1, i.v.) inhibited histamine (30μg kg−1, i.v.)-and bradykinin (0·3 μg kg, i.v.)-induced airway microvascular leakage. These effects of rolipram were obtained at doses which inhibit histamine (7–20 μg kg−1 min−1)-induced bronchoconstriction (IC50 = 3 ± 1 μg kg, i.v.) without depressing arterial blood pressure in the guinea-pig. Aminophylline (50 mg kg−1) did not change the effect of PAF. The anti-exudative effect of rolipram is of potential therapeutic value in asthma.

ROLIPRAM INHIBITS PAF-INDUCED AIRWAY MICROVASCULAR LEAKAGE IN GUINEA-PIG - A COMPARISON WITH MILRINONE AND THEOPHYLLINE

1992

The effects of 3 phosphodiesterase (PDE) inhibitors, rolipram (PDE IV), milrinone (PDE III) and theophylline (non-selective) on PAF (50 ng kg-1; iv)-induced airway vascular leakage have been evaluated in guinea-pigs. Rolipram (3-300 micrograms kg-1; iv) reduced the increase in permeability induced by PAF at all airway levels whereas milrinone (10-1000 micrograms kg-1; iv) and theophylline (30 mg kg-1; iv) were without effects. The anti-leakage activity of rolipram may be of therapeutic value in asthma.