Influence of gelucires and rhodopases on sustainment of in -domethacin via solid dispersions

Solid dispersions of indomethacin in different release retarding materials; namely, Gelucire 50/02 and Gelucire 50/13, Rhodopas M and Rhodopas H were prepared by fusion and coprecipitation methods, respectively. Solid dispersions were compressed into tablets where both physical parameters and dissolution were studied. The effect of various release retardants on anti-inflammatory characteristic of indomethacin adopting rat paw edema and ulcerogenicity on rat stomach from the most appropriate preparations reached were done. A satisfactory prolongation of drug dissolution from its tablets made with Gelucires was obtained from drug tablets containing 10% w/w of Gelucire 50/02. However, drug tablets prepared with 2.5% of the same polymer showed a shorter retardation time. The percentage of drug release was decreased by increasing the percentage of Gelucire 50/02. In contrast, the increasing Gelucire 50/13 concentration caused a remarkable increase in drug release from its tablets. On the other h and, indomethacin tablets prepared with Rhodopases M and H showed a remarkable protraction of the drug release. The greatest protraction was obtained with 6% Rhodopas H that was too excessive to attain a reasonable level

Microencapsulation of indomethacin using different polymers

Indomethacin microcapsules were prepared with three different polymers; namely, ethyl cellulose 100[EC], Eudragit RSPM [Eud] and sodium carboxymethylcellulose [Na CMC] using solvent-evaporation technique with the first two polymers and coacervation-phase separation by electrolyte addition technique with the latter. Kollidon K-25 was used as a channeling agent. All the prepared microcapsules were subjected to drug content determination, microscopical examination, particle size analysis and drug release studies. The anti- inflammatory characteristic adopting rat paw edema method and ulcerogenicity in terms of ulcer index on rat stomach of indomethacin from the most appropriate preparation reached were studied

Influence of certain stabilizers on physical stability and rheology of allopurinol suspension

Identification of surface charge of allopurinol powder was established by promotion of flocculation of drug suspension with positively charged electrolyte viz., aluminum chloride and negatively charged one viz., potassium dihydrogen phosphate where the drug was proven to be positively charged. Wettability of allopurinol powder was tested with certain non-ionic surfactants and polyols via packed drug column technique where 15% of sorbitol was optimum for the purpose. Stabilization of allopurinol suspension in a deflocculated manner was done with certain finely dispersed solids where 5% of aerosil 200 and 1% of veegum HV produced products with pouring, redispersing and physical stability properties over 3 months associated with pseudoplastic, thixotropic flow characteristics. Other tested stabilizers of natural, synthetic or water-soluble cellulose derivatives yielded deflocculated drug suspensions which were not as good as aerosil 200 and veegum HV relevant to stability and rheology. Flocculated drug suspensions stabilized with either 8% of aerosil 200 or 0.1% of carbopol 940 were sufficiently pourable, redispersed, physically stable over 3 months and associated with pseudoplastic, thixotropic flow with the first agent and pseudoplastic flow pattern with the second

Modulation of anti in flammatory action and ulcerogenically of piroxicam via hydrotropic and complexing solubilization

Solubilized systems of piroxicam with the aid of certain hydrotropic and complexing agents viz., nicotinamide, sodium gentisate, sodium benzoate, sodium salicylate, and gentisic acid ethanolamide were prepared. Both nicotinamide and gentisic acid ethanolamide in 10-40% solubilized the therapeutic dose of piroxicam per 5 ml volumes. The spectral analysis as well as thin-layer chromatography revealed that both nicotinamide and sodium benzoate solubilized piroxicam via hydrotropy, while each of sodium salicylate, sodium gentisate, and gentisic acid ethanolamide solubilized the drug through complex formation. The continuous variation [Job's method] applied to determine the stoichiometric ratio of the reached complexes indicated 1: 2, 2: 1 and 3: 2 ratios for piroxicam and each of gentisic acid ethanolamide, sodium gentisate, and sodium salicylate, respectively. The pharmacological screening revealed that solubilized systems of piroxicam with nicotinamide or gentisic acid ethanolamide improved the anti-inflammatory activity of the drug compared to its commercial product. However, solubilized piroxicam proved to be ulcerogenic