These are noncrystalline, nonglassy, thermoreversible (thermoplastic) solid materials composed of a liquid organic phase entrapped in a three-dimensionally cross-linked network. The liquid may be an organic solvent, mineral oil or vegetable oil. These systems are based on self-assembly of the structurant molecules. Organogels find potential applications in pharmaceuticals, cosmetics, art conservation and food. An example…
It is a network of hydrophilic polymer chains, sometimes occurring as a colloidal gel in which water is the dispersion medium. The polymers may be of natural or synthetic origin. The following are the uses of hydrogels:
Learning Objectives Gels are semisolid preparations usually homogeneous and clear, consisting of a liquid phase within a three-dimensional polymeric matrix that is physically or sometimes chemically cross-linked by suitable gelling agents. Gels are applied to the skin or certain mucous membranes for various purposes such as protective, therapeutic or prophylaxis. Alternatively, it is a coherent…
As creams are widely used for various body parts, general tests such as qualitative and quantitative tests should be done.
Learning Objectives Creams are homogeneous, semisolid preparations consisting of opaque emulsion systems. Their consistency and rheological properties depend on the type of emulsion, either w/o or o/w, and on the nature of the solids in the internal phase. Creams are intended for application to the skin or certain mucous membranes for protective, therapeutic or prophylactic…
In a sample of 10 units, each suppository should contain within ±15% of the average amount of active ingredient. However, if up to three individual units deviate by more than ±15% but are within ±25% of the average amount of the active ingredient, a further 20 units drawn from the same original sample as the…