Verapamil preparations

An example of electrodes of different types, e.g with a coated graphite wire, used for determination of pharamaceutical substances is verapamil electrode [50], The polymer membrane contains 3.6% of verapamil-phosphomolybdate complex and 62.0% of dioc-tylphthalate DOP. The electrode has the slope of 62.6 mV decade" of the response curve in the range of 6 x 10 to 1 x lO mol L" the detection limit (LDL) is 1.9 x 10 mol L. The electrode was stored for approx. 1 year, after which determination of the active ingredient in the verapamil preparation was performed, showing 73.5% of the active ingredient. 

A new brush-type CSP, the Whelk-0 1, was used by Blum et al. for the analytical and preparative-scale separations of racemic pharmaceutical compounds, including verapamil and ketoprofen. A comparison of LC and SFC revealed the superiority of SFC in terms of efficiency and speed of method development [50]. The Whelk-0 1 selector and its homologues have also been incorporated into polysiloxanes. The resulting polymers were coated on silica and thermally immobilized. Higher efficiencies were observed when these CSPs were used with sub- and supercritical fluids as eluents, and a greater number of compounds were resolved in SFC compared to LC. Compounds such as flurbiprofen, warfarin, and benzoin were enantioresolved with a modified CO, eluent [37]. 

Calcium is contraindicated in patients with hypercalcemia or ventricular fibrillation and in patients taking digitalis. Calcium is used cautiously in patients with cardiac disease. Hypercalcemia may occur when calcium is administered with the thiazide diuretics. When calcium is administered with atenolol there is a decrease in Hie effect of atenolol, possibly resulting in decreased beta blockade. There is an increased risk of digitalis toxicity when digitalis preparations are administered with calcium. The clinical effect of verapamil may be decreased when the drug is administered with calcium. Concurrent ingestion of spinach or cereal may decrease file absorption of calcium supplements. 

It was an outstanding experience to plan, organize and realize this book, and to work with such a distinguished group of contributors. I hope that the readers will enjoy the work they did. I won new friends during this book project, one of which is Pierre-Alain Carrupt. He prepared the cover graphics, which represents the molecular lipophilicity potentials for my PhD molecule verapamil in its extended and folded conformation. 

All chemicals were used as received. PDADMAC and PAMPS were obtained from Aldrich Chemical Co. (Milwaukee, WI). Diclofenac sodium, sodium sulfathiazole, labetalol HCl, propranolol HCl, verapamil HCl, and diltiazem HCl were purchased from Sigma Chemical (St. Louis, MO). Dextrose USP was obtained from Amend Co. (Irvinton, NJ). Water was distilled and deionized using a Nanopure purihcation system (Fischer Scientihc, Fair Lawn, NJ). Simulated intestinal fluid was prepared using a O.OIM phosphate buffer (sodium phosphate monobasic and potassium phosphate dibasic) at pH 7 and 5.5 with different amounts of NaCl to vary the ionic strength. Simulated gastric fluid (pH 1.5) was prepared with concentrated HCl with different amounts of NaCl to vary the ionic strength. 

L. Miller and R. Bergeron, Analytical and preparative resolution of enantiomers of verapamil and norverapamil using a cellulose-based chiral stationary phase in the reversed-phase mode, J. Chromatogr., 648 36(1993)... 

P-gp associated ATPase is vanadate sensitive. A membrane product prepared from baculovirus infected insect cells containing this activity is now commercially available from Gentest Corp. (Woburn, Massachusetts, U.S.). Substrates of P-gp, such as verapamil, have been demonstrated to stimulate this vanadate-sensitive membrane ATPase (123). By determination of inorganic phosphate liberated in the reaction containing a P-gp preparation and a test compound, in the presence and absence of vanadate, one can determine if the test compound is a substrate/inhibitor of P-gp (123,422). Any compound that binds to P-gp would stimulate the magnesium-dependent ATPase, and thus, this method cannot distinguish between a substrate and inhibitor of P-gp. 

Verapamil hydrochloride is incompatible with alkaline preparations and drugs such as aminophylline, nafcillin sodium, and sodium bicarbonate.128129... 

Vassilev et al. (1993) exposed Wistar rats to subtoxic doses of Co2+ or Ni2+, receiving Co(N03)2 or NiS04 with drinking water for 30 days, and measured the changes in the contractile responses to carbachol and in the inhibitory effects of verapamil and nitrendipine on isolated smooth muscle preparations of the ileum and the trachea. 

Analogues of verapamil (1) were also studied for their calciiun channel antagonist activity, and their potency for isotonic contractile response of cat capillary muscle preparation was reported [30], which was foimd to be correlated with the electronic constant and the molecular volume of the B-ring substituents as ... 

The ( )- and (Z)-a,p-unsaturated acyls (19) and (20) have also been methylenated as part of an asymmetric route to cy-clopropanecarboxylic acid derivatives. The acryloyl complex, which has been used in asymmetric Diels-Alder reactions as well as a verapamil precursor synthesis, has not been prepared in optically active form from (2), but can be prepared via an elimination reaction from (5). ... 

One of the most widely used calcium channel blockers is verapamil. Verapamil hydrochloride was assayed from pharmaceutical preparations by ElGhany et al. [133]. The separations were performed on 200 x 100 mm and 100 x 100 mm silica gel 60 F254 plates using an ethyl acetate/methanol/water mobile phase and scanning the plates at 278 nm. The accuracy and precision data for the assay of spiked verapamil samples and the recovery data of verapamil from commercial preparations are shown in Tables 10.20 and 10.21. 

THE RECOVERY DATA OF VERAPAMIL FROM COMMERCIAL PREPARATIONS. REPRODUCED WITH PERMISSION FROM (I33 ... 

Goracinova, K. Klisarova, L. Simov, A. Fredro-Kumbaradzi, E. Petrusevska-Tozi, L. Characterization of fluid bed prepared granulates with verapamil hydrochloride as active substance. Acta. Pharm. 1996, 46, 147-153. 

Sipahigil O, Dortunc B. Preparation and in vitro evaluation of verapamil hydrochloride and ibuprofen containing carrageenan beads. Int ] Pharm 2001 228(1-2) 119-128. 

Povidone reduces the adherence of oral bacteria to tooth enamel and therefore it could be used in buccal preparations e.g. mouthwash solution as microbial antiadherent agent [589]. It also can be used as mucoadhesive for buccal coats of verapamil [612] or for bioadhesive buccal tablets of nicotine [639,641]. 

The potential role of the calcium current in the genesis of arrhythmias was discussed above. Verapamil (M, which inhibits calcium influx, can suppress experimental arrhythmias30 Another calcium blocker, nifedipine ( 13a), inhibits irregular rhythms produced by calcium in isolated atrial preparations.31 The calcium antagonist TMB-6( lk) was reported to be as effective as lidocaine in suppressing digoxin-induced arrhythmias in dogs.32 As expected, inhibition of calcium influx leads to depression of cardiac contractility and atrioventricular conduction. 

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