Suppositories, method of preparation

Suppositories

Suppositories: “Suppositories are semisolid dosage form of medicament for insertion into body cavities other than mouth”. 1. Rectal suppositories – They are meant for introduction into rectum for systemic effects. 2. Vaginal suppositories – They are also called pessaries. They are used in vaginas for local effects. 3. Nasal suppositories – They are also called … Read more

Solubility of gas in liquids

The solubility of gas in liquids is the concentration of dissolved gas in the liquid when it is in equilibrium with the pure gas above the solution. Examples of gas in a liquid include effervescent preparations containing dissolved carbon dioxide, ammonia water, and hydrochloride gas. Aerosol products containing nitrogen or carbon dioxide as propellant are … Read more

Mechanisms of solute solvent interactions

Mechanisms of solute solvent interactions: A solute dissolves in a solvent when it forms favorable interactions with the solvent. This dissolving process all depends on the free energy changes of both the solute and the solvent. The free energy of solvation is a combination of several factors. The process can be considered in three stages: … Read more

Difference between solid and liquid mixing

Difference between solid and liquid mixing

Difference between solid and liquid mixing: Industrial applications involve the mixing of solids to solids such as free-flowing solids to pasty materials, solids to liquids, and solids to gas, liquids to liquids, and liquids to gas. Liquid mixing Solid mixing (i) Fluid mixing is generally associatedwith liquid-liquid mixing and liquidgas mixing. (i) Mixing of solids … Read more

Indirect Contact Heat Exchangers

Storage Type Heat Exchanger

The fluid streams remain separate in an indirect-contact heat exchanger, and heat is transferred constantly through a separating wall or into and out of a wall. Thermally interacting fluids do not come into direct touch. Surface heat exchangers are another name for this type of heat exchanger. Direct-transfer heat exchangers, storage heat exchangers, and fluidized-bed … Read more