p
        
        
          K
          
            
              a
            
          
        
        =
      
    
    {\displaystyle \mathrm {p} K_{{\ce {a}}}=}
   4.61
Commercially available minoxidil topical solution should be stored at a temperature of 20-25 °C. Extemporaneous formulations of minoxidil have been reported to have variable stability, depending on the vehicle and method of preparation, and the FDA requests that physicians and pharmacists refrain from preparing extemporaneous topical formulations using commercially available minoxidil tablets. Minoxidil tablets should be stored in well-closed containers at 15-30 °C. Minoxidil, 6-amino-1,2-dihydro-1-hydroxy-2-imino-4-piperidinopyrimidine, is synthesized from barbituric acid, the reaction of which with phosphorous oxychloride gives 2,4,6-trichloropyrimidine. Upon reaction with ammonium, this turns into 2,4-diamino-6-chloropyrimidine. Next, the resulting 2,4-diamino-6-chloropyrimidine undergoes reaction with 2,4-dichlorophenol in the presence of potassium hydroxide, giving 2,4-diamino-6-(2,4-dichlorophenoxy)-pyrimidine.
Phototherapy may be necessary if blood accumulation is significant leading to jaundice. Rarely, anaemia can develop needing blood transfusion. The presence of a bleeding disorder should be considered but is rare.Cephalohematomas typically resolve spontaneously within weeks or months of birth, however calcification can occur in 3-5% of cases. While aspiration to remove accumulated blood and prevent calcification has generally been recommended against due to risk of infection, modern surgical standards and antibiotics may make this concern unfounded, and needle aspiration can be considered a safe intervention for significantly-sized cephalohematomas that do not resolve spontaneously after one month. See also
Caput succedaneum
Cephal
Chignon
Hematoma
Subgaleal hemorrhage

References
External links

Differentiating Cephalhematoma from Caput Succedaneum