Can you give me a composition for the preparation of a lotion with 2% ketoconazole?

There is indeed a Ketoconazole 2% lotion found on the Internet. But no data on the composition. A literature study provides the following information.  

Ketoconazole is a product that is very difficult to get in solution. In water practically insoluble and in ethanol 1 on 54 parts. At pH = 2.7 the solubility = 3.5% while at pH = 4.0 the value = 1.08%. Thus, preparing   a medically acceptible preparation remains difficult. For a 1% solution, some possibilities are described. This based on pure   PEG 400 is not suitable for the scalp.  

In the next solution (1) The PEG 400 is diluted with water wardoor the stickies decreases. The composition reads: Ketonazole   1.0 g, PEG 400 67.5 G, Nipagine 50 mg, Nipasol 20 mg, NaCl 270 mg and water up to 100 ml.  

Perhaps an ethanol-based solution is not excluded. I found the following formula (2): Ketoconazole x   G, Ethanol 96 ° 45.0 G and water up to 100 g. X is   not filled in! It is evident that and X and the amount of ethanol are irrevocably linked. As the amount of ketoconazole rises as the amount of water decreases. I doubt that here the alcohol level is sufficient to keep 1 g of ketoconazole in solution.  

A third possibility is formula (3): Ketoconazole 1.0 g, benzyl alcohol 20.0 g, propylene glycol 30.0 g and ethanol 70 ° to 100 g. It is recommended to   depart from Erthanol 94 ° and dilute with water. 49 g Ethanol 70 ° is required for this preparation. A small calculation gives you the amount of ethanol 96 ° and the amount of water.

A fourth possibility (4) consists of the use of acid for the formation of a soluble ketoconazole salt. This technique is applied in the following formula: Ketoconazole 1.0 g, salicylic acid 3.0 g, glycerin 10 g and ethanol 90 ° (V/V) to 100 g. In the literature a discoloration of this solution is indicated. Perhaps the addition of Na2EDTA   can remedy this?  

In addition, the composition (5) of a lotion with miconazole nitrate remains. The composition is worded as follows: Miconazole nitrate 1.0   g; Propylene glycol 20.0 g; Cremophor EL   12.0 g; Lactic acid 2   g; Alcohol UITW. Gebr. 40 g; and water 25   g  

Decision

A lotion with 2% ketoconazole (KN)   is not impossible but the composition of the formula will have to be tried out. As basis can be taken Formula 2 and 3. I would opt for Formula 3. One can try the case for a small amount of e.g. 25 ml or G and   follow the following methodology.

In The Benzyl alcohol and the alcohol out W. Gebr. 94 ° the KN is dissolved; after which the propylene glycol is added. After mixing, stirring well, is very slowly diluted with water in which it is observed or is cloudy. If it forms a cloudy   eg 3 ml of alcohol is added to dissolve the cloudy. After this, water is diluted again to the total volume. Once again cloudy, a small amount of alcohol is added.  

Succeed, this test can be repeated but with the addition of a corresponding amount of Cremophor EL and lactic acid-see composition 5

Does not succeed either, I fear that we should prepare a 1% lotion.