Search tips
Search criteria 


Logo of aapspharmspringer.comThis journalToc AlertsSubmit OnlineOpen Choice
AAPS PharmSciTech. 2000 December; 1(4): 35–42.
Published online 2000 October 5. doi:  10.1208/pt010430
PMCID: PMC2750454

Formulation variables affecting drug release from xanthan gum matrices at laboratory scale and pilot scale


The purpose of this research was to study processing variables at the laboratory and pilot scales that can affect hydration rates of xanthan gum matrices containing diclofenac sodium and the rate of drug release. Tablets from the laboratory scale and pilot scale proceedings were made by wet granulation. Swelling indices of xanthan gum formulations prepared with different amounts of water were measured in water under a magnifying lens. Granules were thermally treated in an oven at 60°C, 70°C, and 80°C to studythe effects of elevated temperatures on drug release from xanthan gum matrices. Granules from the pilot scale formulations were bulkier compared to their laboratory scale counterparts, resulting in more porous, softer tablets. Drug release was linear from xanthan gum matrices prepared at the laboratory scale and pilot scales, however, release was faster from the pilot scales. Thermal treatment of the granules did not affect the swelling index and rate of drug release from tablets in both the pilot and laboratory scale proceedings. On the other hand, the release from both proceedings was affected by the amount of water used for granulation and the speed of the impeller during granulation. The data suggest that processing variables that affect the degree of wetness during granulation, such as increase in impeller speed and increase in amount of water used for granulation, also may affect the swelling index of xanthan gum matrices and therefore the rate of drug release.

Keywords: Xanthan gum, Diclofenac sodium, Granulation, Hydration Laboratory, Pilot scale

Full Text

The Full Text of this article is available as a PDF (313K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Lapidus H, Lordi GN. Drug release from compressed hydophyllic matrices. J Pharm Sci. 1968;57:1292–1301. doi: 10.1002/jps.2600570803. [PubMed] [Cross Ref]
2. Mockel JE, Lippold BC. Zero-order drug release from hydrocolloid matrices. Pharm Res. 1993;90:1066–1070. doi: 10.1023/A:1018931210396. [PubMed] [Cross Ref]
3. Kim CJ. Drug release form compressed hydrophillic POLYOX-WSR tablets. J Pharm Sci. 1995;84:303–306. doi: 10.1002/jps.2600840308. [PubMed] [Cross Ref]
4. Lee PI, Peppas NA. Prediction of polymer dissolution in swellable controlled-release systems. J. Control Rel. 1987;6:207–215. doi: 10.1016/0168-3659(87)90077-0. [Cross Ref]
5. Bumphrey G. ‘Extremely useful’ new suspending agent. Pharm J. 1986;237:665–671.
6. Lu MF, Woodward L, Borodkin S. Xanthan gum and alginate based controlled release theophylline formulations. Drug Dev Ind Pharm. 1991;17:1987–2004. doi: 10.3109/03639049109048063. [Cross Ref]
7. Talukdar MM, Plaizier-Vercammen J. Evaluation of xanthan gum as a hydrophillic matrix for controlled release dosage form preparations. Drug Dev Ind Pharm. 1993;19:1037–1046. doi: 10.3109/03639049309062999. [Cross Ref]
8. Tobyn MJ, Staniforth JN, Baichwal AR, McCall TW. Prediction of physical properties of a novel polysaccharide controlled release system. Int J Pharm. 1996;128:113–122. doi: 10.1016/0378-5173(95)04230-X. [Cross Ref]
9. Sujja-areevath J, Munday DL, Cox PJ, Khan KA. Relationship between swelling erosion and drug release in hydrophilic natural gum mini-matrix formulations. Eur J Pharm Sci. 1998;6:207–217. doi: 10.1016/S0928-0987(97)00072-9. [PubMed] [Cross Ref]
10. Dhopeshwarkar V, Zatz JL. Evaluation of xanthan gum in the preparation of sustained release matrix tablets. Drug Dev Ind Pharm. 1993;19:999–1017. doi: 10.3109/03639049309062997. [Cross Ref]
11. Ueberreiter K. The solution process. In: Crank J, Park GS, editors. Diffusion in Polymers. London: Academic Press; 1967. pp. 219–257.
12. Kristensen HG. Particle agglomeration. In: Ganderton D., Jone T, McGinity J, editors. Advances in Pharmaceutical Serences. London: Academic Press; 1995. pp. 221–225.
13. Leuenberger H, Bonny JD, Lerk CF, Vromans H. Relationship between crushing strength and internal specific surface area of lactose compacts. Int J Pharm. 1989;52:91–100. doi: 10.1016/0378-5173(89)90282-2. [Cross Ref]
14. Jansson PE, Kenne L, Linderberg B. Structure of extracellular polysaccharide fromXanthamonas comopestris. Carbohydr Res. 1975;45:275–282. doi: 10.1016/S0008-6215(00)85885-1. [PubMed] [Cross Ref]

Articles from AAPS PharmSciTech are provided here courtesy of American Association of Pharmaceutical Scientists