Monday, December 22, 2008

Robustness of Analytical Chemical Methods and Pharmaceutical Technological Products

Hardbound. In analytical chemistry and pharmaceutical technology attention is increasingly focussed on improving the quality of methods and products. This book aims at fostering the awareness of the potential of existing mathematical and statistical methods to improve this quality. It provides procedures and ideas on how to make a product or a method less sensitive to small variations in influencing factors. Major issues covered are robustness and stability improvement and ruggedness testing. General strategies and a theoretical introduction to these methods are described, and thorough overviews of methods used in both application areas and descriptions of practical applications are given.

Features of this book:

• Gives a good overview of mathematical and statistical methods used in two application areas, i.e. pharmaceutical technology and analytical chemistry

• Illustrates the different approaches available to attain robustness


Saturday, December 20, 2008

Formulation design of oxcarbazepine fast-release tablets prepared by melt granulation technique

This work describes a melt granulation technique to improve the dissolution characteristics of a poorly water-soluble drug, oxcarbazepine. Melt granulation technique is a process by which pharmaceutical powders are efficiently agglomerated by a meltable binder. The advantage of this technique compared to conventional granulation is that no water or organic solvents are needed. Because there is no drying step, the process is less time consuming and uses less energy than wet granulation. In particular, the granules containing oxcarbazepine were prepared using polyethylene glycol (PEG) 4000 as a melting binder and lactose monohydrate as a hydrophilic filler. The potential of the intragranular addition of starch as a dissolution enhancer and a disintegrative agent was also evaluated. After analysis of their solid state was performed by means of x-ray powder diffraction (XRD), the granules were characterized from technological and dissolution point of view. The subsequent step comprised of the preparation and evaluation of the tablets, including the effect of the extragranular introduction of starch. Besides the remarkable enhancement of drug dissolution rate of the granulates in comparison to physical mixtures and pure drug, no significant differences were found between the dissolution profiles of the granulates containing lactose or starch. However, the difficult disintegration and bad dissolution performance of the tablets not containing intragranular starch so it is necessary to add disintegrant in the granulating mixture. Moreover, the extragranular addition of a small amount of starch gave rise to further amelioration of the disintegration and dissolution performances.


Solubility enhancement and development of dispersible tablet of meloxicam

The present research work investigates enhancement of dissolution profile of meloxicam using solid dispersion (SD) with various polymers. The work also describes the formulation of dispersible tablet (DT) and effervescent tablet of meloxicam. PEG 6000, PEG 8000, PEG 20000, Lutrol F-127, and β-cyclodextrin were selected for the preparation of SD. The SDs were prepared by melting and solvent evaporation methods. Dissolution studies were performed for plain meloxicam, SDs, and tablet formulations. Infrared spectroscopy and differential scanning calorimetry were performed to identify the physicochemical interaction between drug and carriers. Dispersible tablets and effervescent tablets were compared with tablet containing plane drug for dissolution profile. Dissolution of DT improved significantly in SD product (<95% in 1 min).


Formulation and evaluation of dispersible taste masked tablet of roxithromycin

oxithromycin is a broad spectrum, semisynthetic macrolide antibiotic, having bitter taste. In the present study, an attempt has been made to mask the bitter taste of roxithromycin by complexation technique. Weak cation exchange resins Indion 214 and Amberlite IRP64, polymer carbopol 934P were used in formulation of complexes with the drug. The loading process was optimized for the pH of loading solution and resin or polymer:drug ratio. The complexes were evaluated for bulk density, angle of repose, taste masking, and in vitro drug release. In vitro drug release studies showed more than 80% drug release from the optimized formulation within 30 min. Amberlite IRP64 was found to be better complexing agent for masking the bitter taste of roxithromycin.


Simultaneous spectrophotometric estimation of rabeprazole sodium and itopride hydrochloride in capsule formulations

A simple, precise, and economical procedure for the simultaneous estimation of rabeprazole sodium and itopride hydrochloride in tablet formulation has been developed. Rabeprazole sodium belongs to the class of proton pump inhibitor and Itopride hydrochloride belongs to the class of anticholinesterase activity as well as dopamine D2 receptor antagonistic activity, is being used for the symptomatic treatment of various gastrointestinal motility disorders. The present method involves the solving of simultaneous equations (Vierodt’s method). Rabeprazole sodium has absorbance maxima at 283 nm in phosphate buffer (pH 7.4) and itopride hydrochloride absorbance maxima at 258 nm in phosphate buffer (pH 7.4). Both these drugs obey Beer’s law in the concentration range employed for the present method. The result of analysis has been validated statistically by recovery studies. The slope and intercept for rabeprazole sodium were 0.0407 and 0.02 and for itopride hydrochloride were 0.0214 and 0.168, respectively, as determined by the method of least squares. The results were found satisfactory and reproducible. The method was applied successfully for the estimation of rabeprazole sodium and itopride hydrochloride simultaneously in tablet dosage to form without the interference of common excipients.