Emulsions can encounter several stability issues due to the immiscible nature of their components. Common problems include creaming, flocculation, coalescence, and phase separation. Below, we discuss these issues and provide methods to overcome them. 1. Creaming Definition: Creaming occurs when the dispersed droplets in an emulsion migrate toward the top or bottom of the system … Read more
Emulsions are mixtures of two immiscible liquids (usually oil and water) where one liquid is dispersed as droplets within the other. The process of preparing an emulsion typically involves energy input to break up the dispersed phase into fine droplets and stabilize the system to prevent coalescence. Below are common methods used for the preparation … Read more
Several tests can be performed to identify whether an emulsion is oil-in-water (O/W) or water-in-oil (W/O): Dilution Test: Mix a small amount of emulsion with water: If the emulsion dilutes easily and remains homogeneous, it is an O/W emulsion. If the emulsion does not mix and appears heterogeneous, it is a W/O emulsion. This works … Read more
Definition of Emulsifying Agents An emulsifying agent (or emulsifier) is a substance that stabilizes an emulsion by improving its kinetic stability. Emulsifiers work by reducing surface tension at the interface between the oil and water phases, making it easier to mix and stabilize the two phases. In pharmaceuticals, emulsifiers can also affect the bioavailability and … Read more
Definition of Emulsions Emulsions in pharmaceutics is a heterogeneous system consisting of two immiscible liquids (often oil and water), where one liquid is dispersed in the other as small droplets. Emulsion is typically unstable and require stabilizing agents (emulsifiers) to maintain the dispersion. Classification of Emulsions Oil-in-Water (O/W) Emulsion: Oil droplets are dispersed in a … Read more
Definition of Deflocculated suspension In a deflocculated suspension, solid particles remain discrete and uniformly dispersed throughout the liquid medium. While initially more uniform, these suspensions are prone to sedimentation and caking, making redispersion difficult. Preparation of Deflocculated Suspensions Particle size reduction: The solid drug is milled or micronized for proper dispersion, similar to flocculated suspensions. … Read more
Definition A flocculated suspension is one in which solid particles form loose, fluffy aggregates called flocs. These flocs settle quickly but can be easily redispersed upon shaking. Flocculated suspensions are preferred in pharmaceuticals due to their better stability and ease of redispersion. Preparation of Flocculated Suspensions Particle size reduction: The solid drug is milled or … Read more
Definition of Suspensions A suspension is a heterogeneous mixture in which finely divided solid particles are dispersed in a liquid medium. The particles in a suspension are larger than those in a solution and do not dissolve in the liquid. Over time, these solid particles settle out due to gravity, making suspensions distinct from solutions … Read more
Introduction to Biphasic Liquids: Biphasic liquids are systems consisting of two immiscible (non-mixing) liquid phases. These systems are commonly used in the pharmaceutical, cosmetic, and chemical industries. They are typically created when two liquids with different polarities, such as oil and water, are combined. Due to differences in polarity, these liquids do not mix and … Read more
1. Percentage Solutions: These are solutions where the concentration of a solute in a solution is expressed as a percentage. In pharmacy, this typically refers to: Weight/Volume (w/v) Weight/Weight (w/w) Volume/Volume (v/v) percentages. 2. Weight/Volume Percentage (w/v): Used for: Solid substances dissolved in a liquid. Definition: Expressed as grams of solute per 100 mL of … Read more
