Elixirs are clear, sweetened hydroalcoholic solutions intended for oral use and are usually flavored to enhance their palatability. Nonmedicated elixirs are employed as vehicles, and medicated elixirs are used for the therapeutic effect of the medicinal substances they contain. Compared with syrups, elixirs are usually less sweet and less viscous because they contain a lower […]
Preparation of syrups is done by one of four general methods, depending on the physical and chemical characteristics of the ingredients. Methods of syrups preparation Broadly stated, these methods are: Solution of the ingredients with the aid of heat. Solution of the ingredients by agitation without the use of heat or the simple admixture of […]
Syrups are concentrated aqueous preparations of a sugar or sugar substitute with or without flavoring agents and medicinal substances. Syrups containing flavoring agents but not medicinal substances are called nonmedicated or flavored vehicles (syrups). These syrups are intended to serve as pleasant-tasting vehicles for medicinal substances to be added in the extemporaneous compounding of prescriptions […]
A solution, is a homogeneous, molecular, mixture of two or more components. The simplest solution consists of two components, a solute dissolved in a solvent. The solute and the solvent could be in the solid, liquid or gaseous states of matter. Most commonly, pharmaceutical solutions are preparations in which the solid solutes, i.e. drug and […]
Protein binding (PB) plays an important role in the pharmacokinetics and pharmacodynamics of a drug. The extent of protein binding in the plasma or tissue controls the volume of distribution and affects both hepatic and renal clearance. In many cases, the free drug concentration, rather than the total concentration in plasma, is correlated to the […]
Ostwald ripening is a phenomenon that occurs in suspensions, involving changes in particle size distribution and the polymorphic form of a drug. In this process, smaller crystal particles dissolve and then redeposit onto larger crystals, leading to the growth of larger particles over time. Mechanism and Mathematical Description of Ostwald Ripening Particle growth is a […]
The formulation of suspensions possessing optimal physical stability depends on whether the particles in suspension are to be flocculated or to remain deflocculated. One approach involves the use of a structured vehicle to keep deflocculated particles in suspension. A second approach depends on controlled flocculation as a means of preventing cake formation. A third, a […]
A pharmaceutical suspension is a coarse dispersion in which insoluble solid particles are dispersed in a liquid medium. The particles typically have diameters greater than 0.1 μm. Under a microscope, some of these particles can exhibit Brownian movement if the dispersion has low viscosity.[1] Interfacial Properties of Suspension Because suspensions are dispersions of one phase […]
Cyclodextrin (CD) is a group of compounds known as cyclic oligosaccharides. They consist of at least six D-(+)-glucopyranose units linked together by α-1,4 bonds, and are produced through the enzymatic action of Bacillus macerans amylase on starch.[1] Types and Properties of Cyclodextrin Cyclodextrins consist of 6, 7, and 8 units of glucose referred to as […]
Occlusion or inclusion complexes results more from the architecture of molecules than from their chemical affinity. One of the constituents of the complex is trapped in the open lattice or cage-like crystal structure of the other to yield a stable arrangement. Channel Lattice Type In this complex, the host component crystallizes to form a channel-like […]