Correlation and in vitro studies on radioactive and nonradioactive albendazole-beta-cyclodextrin complex tablets.

The work aims to confirm the complexation of albendazole (ABZ) by beta-cyclodextrin (beta-CD), and to compare them with pure ABZ tablets using radioactive and nonradioactive dissolution studies. The complex tablets were prepared by kneading a binary mixture of ABZ and beta-CD and a direct compression method. Nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were examined to prove the formation of complexes in the final products. The radiolabelled tablets were labelled with 99mTc-DTPA. Dissolution studies were performed with radiolabelled and nonradiolabelled tablets in two dissolution media (pH 1.2 and pH 7.4). The tablets were added to an acidic solution (pH = 1.2) to quantify the concentration of the drug inside the beta-CD cavity. The other medium (pH = 7.4) was used to prove the existence of non-complexed drug in each powder, as the drug's solubility increases with pH. It was observed that complexation occurred in all tablets, and beta-cyclodextrin (beta-CD) could increase the aqueous solubility. Further, a correlation was shown between dissolution results for radiolabelled and nonradiolabelled tablets. This study shows that the characterization studies were a good indicator for the ABZ: beta-CD complex. According to the phase solubility studies, the solubility of ABZ increased when the amount of beta-CD increased, and drug release from tablets in pH 7.4 and pH 1.2 media was dramatically improved by the addition of beta-CD compared with the pure ABZ tablet.

The effect of zinc chloride dentifrices on plaque growth and oral zinc levels.

The antiplaque potential of zinc salts has been previously demonstrated. The purpose of the present investigation was to establish the effect of zinc chloride dentifrices on plaque growth and on the concentration of zinc in saliva and plaque. Zinc levels in saliva and plaque were measured by atomic absorption spectrophotometry. Elevated zinc levels were observed in saliva and in plaque for 1 hour after contact with a zinc chloride dentifrice. Increased concentrations of zinc were also observed in plaque residue. Further analysis of data showed that subjects with high rates of plaque growth benefited more from the zinc dentifrices than did those with low rates of plaque growth.

Sustained-release dosage form of oxolamine citrate: preparation and release kinetics.

One of the principal uses of microencapsulation for pharmaceuticals has been the preparation of sustained-release dosage forms which have been usually presented in the form of a suspension or gel. However, a non-disintegrating tablet would be a better formulation to obtain sustained-release effect. Microencapsulation has been employed to provide protection of the core material against atmospheric effects, to cover the unpleasant taste and to enhance the stability. A number of drugs have also been encapsulated to reduce gastric and other GI tract irritations, to alter release properties and to change availability. Oxolamine citrate is one of the synthetic derivatives of 3,5-disubstituted 1,2,4-oxodiazole, used particularly for its antitussive activity. The usual dose of the drug is 200 mg given four times a day. Its use was limited by side-effects of nausea and vomiting. In order to prevent the disadvantages caused by taking the drug four times daily, and to reduce the side-effects, a sustained-release dosage form of oxolamine citrate was prepared by the microencapsulation technique and microcapsules thus formed were pressed into tablets. Dissolution tests were done with microcapsules and tablets formed by microcapsules by using the USPXXI paddle method and dissolution kinetics were studied and evaluated.