Formulation in Pharmacy Practice   2nd Edition

NITRAZEPAM
 
Nitrazepam is practically insoluble in water and slightly soluble in alcohol.  Most brands of nitrazepam tablets are scored and disperse in water.  Simple suspensions of tablets in vehicles of syrup and methylcellulose have been described but there are no formal stability studies.  Formula A is based on a published study.1  Formula B is an alternative suggestion intended for short term use.

Formula A1

Nitrazepam Solution 1mg per mL
 
Nitrazepam powder BP 100  mg
Ethanol 95% 15  mL
Propylene glycol 20  mL
Glycerol 50  mL
Water to   100  mL
 
Expiry:  30 days
 
Stability:   Chemical stability was confirmed for at least nine months.
 
Storage:  Refrigerate.  Protect from light.
Amber glass bottles were used in the study.
 
Note:  If nitrazepam tablets are used instead of powder, the preparation may not be as stable due to the possible effects of tablet excipients.
 

Formula B

Nitrazepam Suspension 1mg per mL
 
Nitrazepam tablets 5mg 20   
Glycerol 20  mL
Methylcellulose 1% 50  mL
Parabens 0.1  %
*Ethanol 95 % mL
Water to   100  mL
 
*The inclusion of ethanol is optional but addition will dissolve some or all of the nitrazepam and may improve dose uniformity.
 
Expiry:  30 days.
 
Storage:  Refrigerate.  Protect from light.
 
Shake well before use.
 

 
REFERENCE
  1. Amadio M, Chambers R, McDonald C.  The development of a paediatric nitrazepam oral solution.  Aust J Hosp Pharm 1993; 23 (1): 82 (Abstract).

 
Formulation in Pharmacy Practice
2nd Edition