Contact lenses: Contact lenses are usually made from polymethyl- methacrylate, a hard hydrophobic plastic, but some softer hydrophilic lenses have been developed and are coming to use. Types of contact lenses: 1- Hard contact lenses 2- Soft contact lenses 1.HARD […]
Suspensions: The physical chemist defines the word “suspension” as a two phase system consisting of an undissolved or immiscible material dispersed in a vehicle (i.e., solid, liquid, or gas). The particles of the dispersed phase vary widely in size, from […]
Methods For Formulation of Suspension: 1-Precipitation method: Three precipitation methods are used: Organic solvent precipitation: Water insoluble drugs can be precipitated by dissolving them in water- miscible organic solvent and then adding organic phase to distilled water under standard conditions. […]
Equipment for Suspensions: 1-Mortar and pestle: It consists of a glass or porcelain mortar and a pestle. Advantages: Small quantity suspenisons can be prepared in the laboratory. Low cost. Simplest operation among all other instruments. Disadvantages: Generally, the final particle size […]
Evaluation of Suspensions: Sedimentation method Rheological method Electro kinetic method 1.Sedimentation method : Two parameters are studied for determination of sedimentation: Sedimentation volume Degree of flocculation Sedimentation volume – The suspension formulation(50mL)was poured separately into100mL measuring cylinders and sedimentation volume […]
FORMULATION COMPONENTS: Oil Phase – Various chemical types of oils are used in the preparation of pharmaceutical emulsions, including hydrocarbons, simple esters, fatty acids, fixed and volatile oils, and waxes. The selection of oil phase is based on the solubility […]
The word “emulsion” comes from the Latin word for “to milk“. An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of […]
EMULSIFICATION TECHNIQUES (EMULSION FORMATION): 1.Conventional method – Dry gum method – Wet gum method 2.Condensation method 3.Phase inversion technique 4.Low-energy emulsification 5.Spontaneous emulsification Emulsion preparation by the commonly used dispersion method requires a sequence of processes for breaking up the […]