Chloroxylenol Solution

Definition

 

Chloroxylenol Solution is a cutaneous solution.

 

Chloroxylenol  50.0 g    

Potassium Hydroxide    13.6 g    

Oleic Acid      7.5 ml    

Virgin Castor Oil    63.0 g    

Terpineol 100 ml   

Ethanol (96 per cent)     200 ml   

Purified Water, freshly boiled and cooled     Sufficient to produce 1000 ml      

In making Chloroxylenol Solution, the Ethanol (96 per cent) may be replaced by Industrial Methylated Spirit1.

 

Extemporaneous preparation

 

The following directions apply.

 

Dissolve the Potassium Hydroxide in 15 ml of Purified Water, add a solution of the Virgin Castor Oil in 63 ml of Ethanol (96 per cent), mix, allow to stand for 1 hour or until a small portion of the mixture remains clear  when diluted with 19 times its volume of Purified Water and then add the Oleic Acid. Mix the Terpineol with a solution of the Chloroxylenol in the remainder of the Ethanol (96 per cent), pour into the soap solution and add sufficient Purified Water to produce 1000 ml.

 

The solution complies with the requirements stated under Liquids for Cutaneous Application and with the following requirements.

 

Content of chloroxylenol, C8H9ClO

 

4.75 to 5.25% w/v.

 

Ethanol content

 

16 to 21% v/v, Appendix VIII F.

 

Assay

 

Dissolve 0.4 g of 4-chloro-o-cresol  (internal standard) in sufficient chloroform to produce 50 ml (solution A). Carry out the method for gas chromatography, Appendix III B, using solutions prepared in the following manner. For solution (1) dissolve 0.10 g of chloroxylenol BPCRS in 10 ml of solution A and dilute to 20 ml with chloroform. For solution (2) place 4 ml of the solution being examined in a separating funnel, add 20 ml of chloroform, mix, add 4 ml of 2M hydrochloric acid and shake. Extract with two further 10 ml quantities of chloroform. Combine the chloroform extracts, dry by shaking with anhydrous sodium sulphate and filter. Prepare solution (3) in the same manner as solution (2) but adding 20 ml of solution A in place of the 20 ml of chloroform.

 

The chromatographic procedure may be carried out using a glass column (1.5 m 4 mm) packed with acid-washed, silanised diatomaceous support (80 to 100 mesh) coated with 3% w/w of polyethylene glycol (Carbowax 20M is suitable) and maintained at 160.

 

Calculate the content of C8H9ClO using the declared content of C8H9ClO in chloroxylenol BPCRS.

 

Labelling

 

The label states (1) the date after which the solution is not intended to be used; (2) the conditions under which it should be stored.

 

The label indicates the pharmaceutical form as 'cutaneous solution'.

 

1The law and statutory regulations governing the use of Industrial Methylated Spirit must be observed.