Dissolution characteristics and oral absorption of digitoxin and digoxin coprecipitates.
A marked increase in the dissolution rates od digitoxin and digoxin was attained by dispersing the drugs in two inert solid carriers, poloxamer 188 and deoxycholic acid. The 1 and 10% (w/w) drug-carrier solid dispersions were prepared by the solvent method. The former dissolved significantly faster than the latter. The oral administration of 10% (w/w) digitoxin-carrier coprecipitates to mice significantly increased toxicity. This observed increase is attributed to an increase in the rate and, possibly, the extent of oral absorption of the drug. Although a 10% coprecipitate of digoxin in both carriers showed an increase in the dissolution rate, no increase in oral toxicity was observed. X-ray diffraction patterns indicated that both digitoxin and deoxycholic acid undergo crystalline modifications due to treatment by the solvent, but the exact nature of the drug-carrier solid dispersions was not revealed.
D000818:Animals; D002626:Chemistry, Pharmaceutical; D004074:Digitoxin / Q000378:metabolism*; D004077:Digoxin / Q000378:metabolism*; D004338:Drug Combinations; D005079:Excipients; D007408:Intestinal Absorption; D008297:Male; D051379:Mice; D012995:Solubility; D014961:X-Ray Diffraction
D004338:Drug Combinations; D005079:Excipients; D004077:Digoxin; D004074:Digitoxin