AAPS PharmSciTech

, Volume 2, Issue 2, pp 14–21 | Cite as

Effect of hydroxypropyl methylcellulose and hydrogenated castor oil on naproxen release from sustained-release tablets

  • M. Helena Amaral
  • J. M. Sousa Lobo
  • D. C. Ferreira


The effect of the concentration of hydrophilic (hydroxypropyl methylcellulose [HPMC]) and hydrophobic (hydrogenated castor oil [HCO]) products, fillers (lactose and dibasic calcium phosphate), and buffers (sodium bicarbonate, calcium carbonate, and sodium citrate) on naproxen release rate was studied. Matrix tablets were prepared by double compression, andIn vitro dissolution tests were performed. The dissolution results showed that an increased amount of HPMC or hydrogenated castor oil resulted in reduced drug release. The inclusion of buffers in the HPMC matrix tablets enhanced naproxen release. For HCO tablets, only sodium bicarbonate enhanced naproxen release. The presence of lactose on HPMC matrix tablets did not show a significantly different result from that obtained with the formulation containing dibasic calcium phosphate as a filler. However, for the tablets containing HCO, the presence of lactose significantly enhanced the naproxen release rate. The matrix-forming materials in this study were suitable for use in sustained-release tablets containing naproxen. The drug release can be modulated by adding suitable amounts of diluents and buffers.


Naproxen Sustained-release Hydrophilic matrix Lipidic matrix 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Todd PA, Clissold SP. Naproxen: a reappraisal of its pharmacology, and use in rheumatic diseases and pain states.Drugs. 1990;40:91–137.Google Scholar
  2. 2.
    Pather S, Russell I, Syce J, Neau S. Sustained release theophylline tablets by direct compression, Part 1: formulation andIn vitro testing.Int J Pharm. 1998;164:1–10.CrossRefGoogle Scholar
  3. 3.
    Salsa T, Veiga F, Pina mE. Oral controlled-release dosage forms. I. Cellulose ether polymers in hydrophilic matrices.Drug Dev Ind Pharm. 1997;23:929–938.CrossRefGoogle Scholar
  4. 4.
    Kibbe AHandbook of Pharmaceutical Excipients. Washington: American Pharmaceutical Association and The Pharmaceutical Society of Great Britain; 1986:49–50.Google Scholar
  5. 5.
    Lachman L, Lieberman HA, Kanig JL.Pharmaceutical Dosage Forms-Tablets. 2nd ed. Vol 1. New York: marcel Dekker Inc; 1989:13.Google Scholar
  6. 6.
    Zecchi V, Rodriguez L, Tartarini A, Chiarini A, Valenti P.In vitro absorption studies on naproxen and its sodium and piperazine salts.Pharm Acta Helv. 1984;59:91–94.Google Scholar
  7. 7.
    US Pharmacopoeia XXIII. Rockville, MD: US Pharmacopeial Convention; 1995:1054.Google Scholar
  8. 8.
    Higuchi T. Mechanism of sustained-action medication. Theoretical analysis of rate of release of solid drugs dispersed in solid matrices.J Pharm Sci. 1963;52:1145–1149.CrossRefGoogle Scholar
  9. 9.
    European Pharmacopeia. 3rd ed. Council of Europe, Strasbourg; 1997:133–135.Google Scholar
  10. 10.
    Morgan S, Preston CL, Timmins P, melia CD. An investigation into the effect of citrate buffering on pH-dependent drug release, hydration and gel layer growth in HPMC matrices.Proceedings of the 18th Pharmaceutical Technology Conference. 1999;2:24–32.Google Scholar

Copyright information

© American Association of Pharmaceutical Scientists 2001

Authors and Affiliations

  • M. Helena Amaral
    • 1
  • J. M. Sousa Lobo
    • 1
  • D. C. Ferreira
    • 1
  1. 1.Centro de Tecnologia do Medicamento, Faculty of PharmacyUniversity of OportoPortoPortugal

Personalised recommendations