In vitro and in vivo evaluation of controlled-release and enteric-coated formulations of sodium salicylate

✍ Scribed by Lars Borgström; Bo Ekman; Hans Larsson; Ido Leden; Åke Lindahl; Arne Melander; Elisabeth Wålin-boll

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Volume: 5
• Category: Article
• ISSN: 0142-2782
• DOI: 10.1002/bdd.2510050308

✦ Synopsis

The bioavailability and pharmacokinetics of salicylic acid (SA) were studied after single and multiple doses of a new slow-release formulation, based on porous membrane diffusion of sodium salicylate (NaSA). A solution of NaSA and an enteric-coated tablet of NaSA were used for comparison. Dissolution rate studies were carried out at various pH values, and both solid formulations showed pH-dependent release rates. The entericcoated tablet released its content rapidly at intestinal pH but slowly and irregularly at gastric pH. The dissolution from the controlled-release formulation at intestinal pH was completed after 6 h and the drug was delivered at a constant rate. At gastric pH the release rate was lower but complete release was obtained within 24h. The novel formulation appeared to offer complete bioavailability of SA and an even and sustained release of SA, allowing twice-daily medication without increased fluctuations in SA concentrations.