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Commercial Tablets (commercial + tablet)
Selected AbstractsPreparation and evaluation of a novel delayed-onset sustained-release system of propranolol hydrochlorideJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2008Xue-mei Feng The objective of this work was to prepare and evaluate a new delayed-onset sustained-release system, comprising a sustained-release core tablet with hydroxypropyl methylcellulose as polymer matrix and an ethylcellulose/Eudragit L coating capable of delaying the drug release. The sustained core containing propranolol hydrochloride as the model drug was prepared by granulate tableting and the polymer coating was applied in a computer-controlled coating pan. The dissolution tests demonstrated that the in-vitro drug release was pH-dependent with sufficient gastric resistance, and the lag time (t10%) could be controlled by adjusting the coating level. Three dosage forms including commercial tablet, sustained-release tablet and the delayed-onset sustained-release tablet were administrated to six beagle dogs and the plasma levels of propranolol hydrochloride were measured with high-performance liquid chromatography. The delayed-onset sustained-release tablet had a lag time of 3.0 h in-vitro and 3.5 h in-vivo, and a tmax of 7.0 h. The relative bioavailability for delayed-onset sustained-release tablet was 96.98% compared with commercial tablets. The results indicate that the new propranolol delayed-onset sustained-release system could achieve a relatively constant drug release followed by a programmed lag time, and this may provide a promising drug delivery form for chronopharmacotherapy of certain cardiovascular diseases. [source] Development and validation of fixed-time method for the determination of isoxsuprine hydrochloride in commercial dosages formsDRUG TESTING AND ANALYSIS, Issue 9 2010Dr Nafisur Rahman Abstract The main aim of this work was to develop a kinetic spectrophotometric method for the quantitative analysis of isoxsuprine hydrochloride in commercial tablets. The method is based on the reaction of isoxsuprine hydrochloride (ISx) with hydroxylamine hydrochloride and ammonium cerium (IV) nitrate in sulphuric acid medium at room temperature which resulted in the formation of yellow-coloured product peaking at 380 nm. The reaction is followed spectrophotometrically by measuring the absorbance as a function of time. Fixed time method (,A = A4,A2, where A2 and A4 refer to absorbance measurements taken at 2 and 4 min, respectively) was adopted for constructing the calibration curve which was found to be linear over the concentration range of 30,80 µgmL,1 with molar absorptivity of 5.95 × 103 L mol,1 cm,1. The method has been applied successfully to the determination of isoxsuprine hydrochloride in tablets. Statistical comparison (point and interval hypothesis tests) of the results showed that there is no significant difference between the proposed method and reference method. Copyright © 2010 John Wiley & Sons, Ltd. [source] Determination of the chiral and achiral related substances of methotrexate by cyclodextrin-modified micellar electrokinetic chromatographyELECTROPHORESIS, Issue 16 2004Roberto Gotti Abstract A cyclodextrin-modified micellar electrokinetic chromatographic (CD-MEKC) method for the determination of the most important potential impurities of methotrexate (MTX): 2,4-diamino-6-(hydroxymethyl)pteridine, aminopterine hydrate, 4-[N -(2-amino-4-hydroxy-6-pteridinylmethyl)- N -methylamino] benzoic acid, 4-[N -(2,4-diamino-6-pteridinylmethyl)- N -methylamino] benzoic acid, and the distomer D -MTX is presented. The MEKC separation of these compounds was optimized by applying a step-by-step approach. The addition of ,-CD to a conventional MEKC system, based on sodium dodecyl sulfate (SDS) as surfactant, showed to be essential for the enantioresolution of racemic MTX as well as for the separation of the achiral impurities. To achieve high-resolution factor between the peaks adjacent to the main component (L -MTX), as required in the analysis of related impurities, the separation conditions were stressed; in particular, the addition of methanol to the CD-MEKC system resulted in a very effective choice. Under the optimized final conditions (100 mM SDS and 45 mM ,-CD in a mixture of 50 mM borate buffer, pH 9.30-methanol (75:25 v/v)), the method was validated showing a general adequate accuracy (93,106% recovery) in the determination of L -MTX related substances at the impurity level of 0.12% w/w with a relative standard deviation (RSD)% lower than 8% (n = 4). The method was successfully applied to the analysis of pharmaceuticals (tablets and injections) which showed to contain the distomer D -MTX as major impurity and aminopterine hydrate as a further related substance in the commercial tablets. [source] Preparation and evaluation of a novel delayed-onset sustained-release system of propranolol hydrochlorideJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2008Xue-mei Feng The objective of this work was to prepare and evaluate a new delayed-onset sustained-release system, comprising a sustained-release core tablet with hydroxypropyl methylcellulose as polymer matrix and an ethylcellulose/Eudragit L coating capable of delaying the drug release. The sustained core containing propranolol hydrochloride as the model drug was prepared by granulate tableting and the polymer coating was applied in a computer-controlled coating pan. The dissolution tests demonstrated that the in-vitro drug release was pH-dependent with sufficient gastric resistance, and the lag time (t10%) could be controlled by adjusting the coating level. Three dosage forms including commercial tablet, sustained-release tablet and the delayed-onset sustained-release tablet were administrated to six beagle dogs and the plasma levels of propranolol hydrochloride were measured with high-performance liquid chromatography. The delayed-onset sustained-release tablet had a lag time of 3.0 h in-vitro and 3.5 h in-vivo, and a tmax of 7.0 h. The relative bioavailability for delayed-onset sustained-release tablet was 96.98% compared with commercial tablets. The results indicate that the new propranolol delayed-onset sustained-release system could achieve a relatively constant drug release followed by a programmed lag time, and this may provide a promising drug delivery form for chronopharmacotherapy of certain cardiovascular diseases. [source] Improvement of the agitation granulation method to prepare granules containing a high content of a very hygroscopic drugJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2006Nobuaki Hirai This study describes a new approach to the preparation of a granulate with a high content of a very hygroscopic powder or drug, using the agitation granulation method, and the development of a tablet formulation using these granulates. A Chinese medicine extract, Hatimi-zio-gan, was used as the model of a very hygroscopic drug. Among the several excipients tested, only porous calcium silicate could be used to prepare granules, with a mixing ratio (extract to porous calcium silicate) from 2:1 to 20:1. With other excipients, very large lumps were formed during the granulation process. The best mixing ratio of extract to porous calcium silicate was 6:1. For preparation of the granules, water could be added to the mixed powder within a range of 1- to 4-times the amount of porous calcium silicate. From these results, it was concluded that the ability of porous calcium silicate to hold large amounts of water in its numerous pores may allow for the preparation of granulates with a high content of very hygroscopic drugs. Starch with partial ,-links, carboxymethyl starch sodium salt and crospovidone were used for selection of the disintegration agent. When crospovidone was used as a disintegration agent, tablets containing about 70% of the Chinese medicine extract disintegrated in less than 7 min, with good dissolution rates. The same process was applied to extracts of Hotyu-ekki-to, Syo-seiryu-to, Boi-ogi-to and Bohu-tusyo-san. The absorption of paeoniflorin, a characteristic monoterpene glucoside contained in Hatimi-zio-gan extract, was evaluated in beagle dogs after oral administration of the Hatimi-zio-gan tablets prepared in this study. The values of Cmax and AUC obtained after administration of the tablets prepared in this study were significantly greater than those obtained for commercial tablets. [source] Polymorphism incidence in commercial tablets of mebendazole: a vibrational spectroscopy investigationJOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2008A. P. Ayala Abstract Mebendazole is a broad spectrum anthelminthic drug, which is widely used in large scale deworming programmes. This active pharmaceutical ingredient exhibits three crystal forms, namely, polymorphs A, B, and C. Therapeutic trials suggested that the most stable form, polymorph A, is inactive. However, the dissolution test normally used as a quality control tool is not able to discriminate among the polymorphs of mebendazole. In this work, the ability of the vibrational spectroscopic techniques (mid and nearinfrared absorption and Raman scattering) for the identification of the crystal form of this compound is evaluated. On the basis of these observations, this methodology is applied to determine the polymorphs of MBZ used in the formulation of the commercial tablets available in the Brazilian and German markets. Copyright © 2008 John Wiley & Sons, Ltd. [source] Simultaneous determination of digoxin and digitoxin by micellar electrokinetic chromatography and application to drug formulationsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2003Hsiu-Hui Tseng Abstract A simple micellar electrokinetic chromatographic method is described for simultaneous determination of digoxin and digitoxin. The simultaneous analysis of digoxin and digitoxin was performed in Tris buffer (10 mM; pH 9) with 90 mM sodium dodecyl sulfate and 10% isopropyl alcohol as an anionic surfactant and organic modifier. Under these conditions, good separation with high efficiency is achieved in short analysis times. Several parameters affecting the separation of the drugs were studied, including the pH and concentrations of the Tris buffer and sodium dodecyl sulfate. The linear range of the method for the determination of digoxin and digitoxin was over 0.01,0.3 mg/mL; the detection limit (signal to noise ratio = 3; injection 3.5 kPa 3 s) was 4 and 6 ,g/mL, respectively. Application of the proposed method to the determination of digoxin in commercial tablets and in injections proved to be feasible. [source] Comparison between micellar liquid chromatography and capillary zone electrophoresis for the determination of hydrophobic basic drugs in pharmaceutical preparationsBIOMEDICAL CHROMATOGRAPHY, Issue 1 2007S. Torres-Cartas Abstract The determination of highly hydrophobic basic compounds by means of conventional reversed-phase liquid chromatographic methods has several drawbacks. Owing to the characteristics of micellar liquid chromatography (MLC) and capillary electrophoresis (CE), these techniques could be advantageous alternatives to reversed-phase chromatographic methods for the determination of these kinds of compounds. The objective of this study was to develop and compare MLC and CE methods for the determination of antipsychotic basic drugs (amitryptiline, haloperidol, perphenazine and thioridazine) in pharmaceutical preparations. The chromatographic determination of the analytes was performed on a Kromasil C18 analytical column; the mobile phase was 0.04 m cetyltrimethylammonium bromide (CTAB), at pH 3, containing 5% 1-butanol, at a flow rate of 1 mL/min. The CE separation was performed in a fused-silica capillary with a 50 mm tris-(hydroxymethyl)-aminomethane buffer, pH 7, at an applied voltage of 20 kV, using barbital as internal stardard. The proposed methods are suitable for a reliable quantitation of these compounds in the commercial tablets and drops in terms of accuracy and precision and require a very simple pre-treatment of the samples. By comparing the performance characteristics and experimental details of the MLC and CE methods we conclude that CE seems to be slightly better than MLC in the determination of highly hydrophobic compounds in pharmaceuticals in terms of resolution and economy, taking into account that the limits of detection are not a handicap in pharmaceutical samples. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||