Suppositories, method of preparation


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 liquids in liquids


Binary Solutions It is very common for two or more liquids to be mixed to make a solution. Therefore, we need to know what liquids can be mixed without precipitation. Examples of pharmaceutical solutions of liquids dissolved in liquids are hydroalcoholic solutions, aromatic waters, spirits, elixirs, lotions, sprays, and some medicated oils that contain a … 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

Diffusion principles in biological systems

Matter moves by diffusion along energy gradients from areas of high concentration to areas of lower concentration. The rate of diffusion depends on temperature, the size of the particles, and the size of the concentration gradient. In biology, the selectively permeable cell membrane creates two special forms of diffusion, namely, osmosis for the diffusion of … Read more

Factors influencing solubility of drugs


Factors influencing solubility: The solubility of most solid solutes is significantly affected by temperature. When some solid dissolves in a liquid, a change in the physical state of the solid analogues (melting) takes place. Heat is required to break the bonds holding the molecules in the solid together. At the same time, heat is given … 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

What is a solubility

Solubility is the ability of one substance to fully dissolve in another substance under specified conditions. The word soluble comes from the fourteenth century, from the Latin word ‘solvere’ meaning to dissolve. The concentration of a solution is usually quoted in terms of the mass of the solute dissolved in a particular volume of solvent. … Read more

Effervescent granules

Effervescent granules

Preparation of effervescent granules Effervescent granules are prepared by two methods: 1) Heat method 2) Wet method Heat Method: A large porcelain or stainless steel evaporating dish is placed over a boiling water bath. Sufficiently hot before placing the powder for the liberation of water from crystallization from citric acid. All the ingredients are powdered, … Read more

What are the Nasal preparations

Nasal preparations are Nasal drops, nasal sprays, nasal powder, and nasal washes. Nasal drops: Nasal drops are monophasic liquid dosage forms, the aqueous solutions of drops, instilled into the nose with the help of a dropper. The oil vehicle is not used for preparation, it is used for long periods it inhibits the movement of … Read more