Solutions

• Solutions are preparations containing one or more drug substances molecularly dispersed in a suitable solvent or a mixture of mutually miscible solvents
• Oral liquids contain one or more substances with or without flavoring, sweetening or coloring agents dissolved in water or co-solvent water mixtures
• Early solutions like fluid extracts, tinctures, spirits, and potions had simpler compositions and preparations compared to contemporary solutions
• Contemporary solutions can be buffered, preserved, flavored, sweetened, adjusted for pH and osmolality, and protected against oxidation
• Types of solutions:

  • Aqueous solutions may contain co-solvent systems like alcohols or other organic solvents with or without added active ingredients
  • Topical solutions are concentrated aqueous preparations of a sugar or sugar substitute with or without flavoring agents and medicinal substances, serving as vehicles for active drugs
  • Elixirs are clear, sweetened, hydroalcoholic solutions usually flavored, suitable for drugs insoluble in water alone but soluble in water-alcohol mixtures, containing solvents like water, alcohol, glycerine, sorbitol, propylene glycol, and polyethylene glycol 300
  • Aromatic waters are clear, saturated aqueous solutions of volatile oils or other aromatic or volatile substances used for internal and external purposes
• Oral liquids generally contain the active drug with or without co-solvent systems, flavorings, sweeteners, colorings, preservatives, buffering agents, antioxidants, or other ingredients
• More drugs are susceptible to degradation in an aqueous solution, but adding buffers to adjust the pH, preservatives, and antioxidants can prevent degradation
• Flavorings and sweeteners can make a drug with a disagreeable taste or odor more palatable, increasing patient acceptance of the preparation and ease of administration