Formulation in Pharmacy Practice   2nd Edition

PREDNISONE/PREDNISOLONE SODIUM
 
 
Prednisone is practically insoluble in water and soluble 1 in 150 parts of ethanol.  Prednisolone is very slightly soluble in water and soluble 1 in 30 parts of ethanol.
Oral liquids of prednisolone, prednisolone sodium phosphate and prednisone are commercially available in many countries.  Prednisone suspensions usually have a pH of 3 - 4.5 and contain 2 - 5% ethanol; solutions have a pH 2.6 - 3.6 and contain 4-6% ethanol.

A number of extemporaneously prepared formulations have been described1-5 and pharmacists often develop their own variations.  The basic principles are:
  1. Inclusion of a co-solvent (usually ethanol) to increase solubility.
  2. Avoidance of alkaline pH as chemical degradation occurs more rapidly under these conditions.
  3. If sodium benzoate is used as a preservative the final pH must be less than 5, preferably about 4.
  4. Flavoured suspending bases are often used to disguise the bitter taste.
  5. Preparations should be protected from light.
  6. Some of the formulations studied have used prednisolone or prednisone powder and the conclusions cannot be applied to formulations prepared from tablets due to possible effects of tablet excipients.
  7. Expiry dates should not exceed one month unless the formulation has been fully validated.


REFERENCES
  1. Gupta VD, Gibbs CW, Ghanekar AG.  Stability of pediatric liquid dosage forms of ethacrynic acid, indomethacin, methyldopate hydrochloride, prednisone and spironolactone.  Am J Hosp Pharm 1978; 35 (Nov): 1382-1385.
  2. Sullivan JA, Hobson LT.  Prednisolone disodium phosphate stability in a prednisolone oral solution.  Aust J Hosp Pharm 1994; 24 (5): 397-398.
  3. Sullivan JA.  Prednisolone stability in a hydroalcoholic prednisolone mixture.  Aust J Hosp Pharm 1991; 21 (Aug): 239-241.
  4. Stafford L, Hope ME, Janney EP, Ailakis JG.  Comparison of paediatric steroid mixtures.  Aust J Hosp Pharm 1998 28 (4): 246-249.
  5. Gupta VD.  High pressure liquid chromatographic evaluation of aqueous vehicles for preparation of prednisolone and prednisone liquid dosage forms.  J Pharm Sci 1979; 68 (Jul): 908-910.

 
Formulation in Pharmacy Practice
2nd Edition