[Comparative dissolution study of drugs using protein hdrolysates]

Kneaded mixtures as well as physical mixtures, of an acidic drug, indomethacin, a basic drug vincamine, and a neutral drug, prednisolone, with gelatin and casein hydrolysates were prepared. Their in vitro dissolution profiles were examined. The dissolution of drugs from the kneaded mixtures was significantly increased compared to the drugs alone as well as their physical mixtures. This increase was most prominent for the acidic drug indomethacin. The casein and gelatin hydrolysates enhanced the dissolution of the three drugs by improving the wettability of the drug particles. Solubility also contributes to the enhancement of dissolution of indomethacin and prednisolone. Buffering was an additional reason in case of indomethacin

Comparative dissolution study of drugs using protein hydrolysates

Kneaded mixtures as well as physical mixtures, of an acidic drug, indomethacin, a basic drug, vincamine, and a neutral drug, prednisolone, with gelatin and casein hydrolysates were prepared. Their in-vitro dissolution profiles were examined. The dissolution of drugs from the kneaded mixtures was significantly increased compared to the drugs alone as well as their physical mixtures. This increase was most prominent for the acidic drug indomethacin. The casein and gelatin hydrolysates enhanced the dissolution of the three drugs by improving the wettability of the drug particles. Solubility also contributed to the enhancement of dissolution of indomethacin and prednisolone. Buffering was an additional reason in case of indomethacin

Effect of oxyethylene chain length of the surfactant on the formation of microemulsion

A series of phase diagrams were established to determine the effect of the oxyethylene chain [OE] length of the surfactants on the formation of the microemulsion. Eumulgin B1 [12-OE], Eumulgin B2 [20-OE] and Eumulgin B3 [30-OE] were selected as surfactants in this study. The cloud point of the surfactant increased with the increase of its oxyethylene chain length. Phase studies have indicated that the configuration of the microemulsion depends on the length of OE chain, while the order of addition of the ingredients has only significant effect in case of Eumulgin B3

High energy states of tolnaftate

Solid dispersions of tolnaftate were prepared using polyvinylpyrrolidone [PVP], polyethylene glycol 20,000 [PEG], urea, thiourea, sucrose and glucose. The dissolution studies showed that the presence of water soluble polymers enhance the dissolution rate of the drug. The amount of tolnaftate released after three hours increased more than 33 times and 25 times on using PVP and PEG respectively as compared with the dissolution of the control untreated powder. The solid dispersion systems were examined using differential thermal analysis [DTA] and showed a reaction at higher temperature only. The dissolution rate was also increased in presence of surface active agent. This may be due to better wetting of the power in the solution presumably lower surface tension. The effect of the used polymers and surfactants on the solubility of tolnaftate was also investigated

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