No abstract available.
Nifedipine

No abstract available.
Nifedipine* ; Vasopressins*

Nifedipine sustained release formulations were made with HPMC, Carbopol, Lycatab, Avicel and magnesi stearat. The effects of the three excipients: HPMC, carbopol, lycatab on the drug release from the formulations were studied. The dissolution profile of a tablet formulation was found to be similar to that of adalat retard 20mg by optimization method and the statistical analysis. This formulation may be used in producing of nifedipine sustained release tablets.
Nifedipine ; Excipients

Nifedifine was incorporated in ethyl cellulose microspheres using the solvent evaporation process. The effects of the EC concentrations, the methylene chloride volumes and the stirring rates on the drug release from microspheres were studied. The dissolution profile of a microsphere formulation was found to be similar to that of adalat retard by the optimization method and the statistical analysis. This formulation may be useful in a nifedipine sustained release dosage form
Nifedipine ; Microspheres

No abstract available.
CREST Syndrome* ; Nifedipine

The HPLC method described herein has sufficient sensitivity to determine the pharmacokinetic parameters of nifedipine in plasma. A single dose cross study was carried out in volunteers comparing the test sustained release nifedipine formulation to Adalat retard tablets. Pharmacokenetic variables were calculated from the nifedipine plasma concentration data and evaluated statistically. The results showed the test formulation to be bioequivalent to the reference tablets.
Nifedipine ; Biological Availability ; tablets

Testing of pharmaceutical dosage forms for in vitro drug release and dissolution characteristics is very important for ensuring batch-to-batch quality control and to optimize formulations during product development. The ideal system for evaluating the drug release characteristics of poorly water-soluble drug formulations (as nifedipine tablets) is to maintain “sink conditions”. Flow-through dissolution systems (e.g. USP XXIV apparatus 4) can be used to over come solubility limitations. In this study, a flow-through dissolution system was installed to evaluate two sustained release nifedipine tablets (Adalat retard 20 mg and Nifedipine retard 20 mg- Life Pharma). The dissolution profiles prove that this system with the pump rate of 14-16 ml/min offers a method to evaluate nifedipine tablets, especially sustained release formulations.
Nifedipine ; tablets ; Pharmaceutical Preparations

No abstract available.
Animals ; Captopril* ; Cisplatin* ; Nifedipine* ; Rats*

A clinical trial was performed to evaluate the tocolytic possibility of nifedipin and to propose a treatment regimen for preterm labor in the National Hospital of Gynecol-Obstet from July 2003 to December 2003. There were 40 cases of preterm labor with gestational age 31 weeks and 3 uterine contractions per minute on average. Patients received a 10 mg sublingual loading dose every 20 minutes (maximum dose 40mg), and followed by 20 mg oral dose every 6- 8 hours. Result: the effectiveness in tocolysis of nifedipin is very fast. It took 60-80 minutes to arrest uterine contraction (70- 80%) (including contractions of high frequency and intensity), especially in urgent tocolysis. The lower the frequency and intensity is, the higher and sooner the effectiveness is. 92.5% of delivery were delayed for 48 hours. 82.85% were postponed until 36 weeks, and the mean time of prolonged pregnacy was 39 days. Side-effects were mild and transient and in normotensive pregnant women blood pressure was almost unaffected. This treatment regimen of nifedipin showed the effectiveness in preterm labor. In brief, nifedipin is an effective, safe, convenient and economic tocolytic agent. It may well represent the best suitable tocolytic alternative currently available and can be used widely in Viet Nam.
Obstetric Labor, Premature, Nifedipine, Tocolysis

The properties of voltage dependent Ca2+ current (VDCC) were investigated in interstitial cells of Cajal (ICC) distributed in the myenteric layer (ICC-MY) of guinea-pig antrum. In tissue, ICC-MY showed c-Kit positive reactions and produced driving potentials with the amplitude and frequency of about 62 mV and 2 times min(-1), respectively, in the presence of 1micrometer nifedipine. Single ICC-MY isolated by enzyme treatment also showed c-Kit immunohistochemical reactivity. These cells were also identified by generation of spontaneous inward current under K+-rich pipette solution. The voltage clamp experiments revealed the amplitude of - 329 pA inward current at irregular frequency. With Cs+-rich pipette solution at Vh=?80 mV, ICC-MY produced voltage-dependent inward currents (VDIC), and nifedipine (1micrometer) blocked VDIC. Therefore, we successfully isolated c-Kit positive single ICC from guinea-pig stomach, and found that ICC-MY potently produced dihydropiridine sensitive L-type voltage-dependent Ca2+ currents (VDCCL).
Interstitial Cells of Cajal ; Nifedipine ; Stomach