The following are the various methods of manufacturing ointments:

Ointment bases are classified into the following categories: Oleaginous (Hydrocarbon) bases: These bases consist of oils and fats and, hence, are hydrophobic in nature, with the least water absorption capacity. Oleaginous bases provide emollient and protective properties by restricting the loss of moisture from the skin and remaining on the skin for prolonged periods. They are…

The ointment base is an integral part of an ointment preparation and serves as a carrier or vehicle for the medicament. Ideal Properties of a Base

Learning Objectives Ointments (unguents) are soft semisolid preparations meant for external application to the skin or mucous membrane. They usually contain medicament that is dissolved, suspended or emulsified in an ointment base. They may contain suitable antimicrobial preservatives. Ointments have emollient and protective action on the skin. They are also used to deliver drugs into…

Iontophoresis This is a process or technique involving the transport of ionic or charged molecules into a tissue by the passage of direct or periodic electric current through an electrolyte solution containing the ionic molecules to be delivered using an appropriate electrode polarity. Electroporation This process involves the application of transient high voltage electrical pulse…

The permeation of the drug involves the following steps: The rate of permeation across the skin (dQ/dt) is given by the expression   dQ/dt = Ps(Cd – Cr)   where Cd = Concentration of the skin penetrant in the donor compartment (on the surface of the stratum corneum) Cr = Concentration of the skin penetrants in the…

Skin can act as a barrier and prevent deep penetration of drug molecules. Percutaneous absorption of most drugs is a passive diffusion process that can be described by Fick’s first law of diffusion. In the initial diffusion stage, drug molecules may penetrate the skin along the hair follicles or sweat ducts and then be absorbed…