Assessment of the pharmaceutical quality of omeprazole capsule brands marketed in Egypt

The pharmaceutical quality of 7 local omeprazole capsule brands in Egypt was assessed relative to the proprietary product [Losec[R]]. Drug content, content uniformity, drug release [using USP test for enteric coated articles and a modified release test] were determined. Products were subjected to a 3-month stability study. Of the 7 brands, 6 had satisfactory drug content and content uniformity. All brands passed the USP drug release test. The modified release test proved to be more discriminative. After 3 months storage, drug content of 3 brands remained > 90% and 2 of these brands maintained drug release above 75%. Changes in pellet appearance during storage were indicative of omeprazole chemical degradation

influence of some formulation excipients on fentiazac release from hard gelatin capsules

The influence of lactose, kaolin and calcium phosphate on the release of fentiazac from hard gelatin capsules has been examined at different pH values. The drug solubility was found to be the determining factor for drug release. The presence of the hydrophilic diluent, lactose, could not assure ideal powder bed deaggregation and subsequent drug liberation unless moderate drug solubility was allowable. The adsorption of fentiazac on the water insoluble diluents, kaolin or calcium phosphate, was evaluated. The results showed that these diluents provided sites for adsorption of fentiazac, which may promote initial drug release, but may also decrease its dissolution efficiency

Solid-state chemical stability of indomethacin in drug adjuvant binary system

Solid-state chemical stability of indomethacin powder was tested periodically in drug-adjuvant binary systems stored at different temperatures and relative humidities over a period of 4-12 weeks. Adjuvants studied were those commonly used in filling hard gelatin capsules as well as hydrophilic adjuvants used in solid dispersion techniques. Undegraded indomethacin in the stored samples was determined by spectrophotometry at intervals during storage. Sorbed moisture was periodically assessed gravimetrically. Parachlorobenzoic acid, one of two hydrolytic products, was determined by HPLC at the end of the storage period. Differential thermal analysis of the freshly prepared drug-adjuvant blends was performed. Indomethacin degradation was least in presence of microcrystalline cellulose and high in presence of lactose, polyvinylpyrrolidone, polyethylene glycol and urea. Degradation of indomethacin in presence of these hydrophilic carriers was influenced by the method of sample preparation. Indomethacin degradation in the majority of systems studied reached equilibrium. The extent of drug degradation was linearly dependent on the amount of moisture sorbed. Differential thermal analysis thermograms indicated the interaction between indomethacin and each of polyvinylpyrrolidone, polyethylene glycol and urea

Effect of sucralfate on the in-vitro availability of some drugs

This work studied the effect of sucralfate on the in vitro release of some drugs which may influence their in vivo availability. Eight products including five conventional tablets [metformin, ketoprofen, norfloxacin, mebeverine and ranitidine] and three prolonged release tablets [metformin- R, theophylline SR and diltiazem] were chosen. In most of the cases, the presence of sucralfate decreased the drug release from their dosage forms. The influence of sucralfate on the in vitro drug release was ranked as follows: Ketoprofen > mebeverine > ranitidine > norfloxacin > metformin for conventional tablets and diltiazem > theophylline SR > metformin-R for controlled release tablets

study of some factors affecting hydrotropic solubilization

The effect of added sodium chloride, temperature and the use of mixed hydrotropes on hydrotropic solubilization was investigated using riboflavin as a model substrate. The results indicated that the solubilizing activity of the hydrotropic agent, sodium salicylate [SS], increased in the presence of NaCl, probably as a result of increased tendency of molecular self-aggregation. Temperature had no appreciable effect on the solubilization of riboflavin by SS over the range 20-40C. Solutions of different binary mixtures of the structurally related hydrotropes, sodium benzoate [SB], sodium salicylate [SS] and sodium gentisate [SG], exhibited solubilizing capacities of intermediate magnitude between those of the respective mixture components, thus implying that hydrotropic solubilization is a collective molecular phenomenon