STORAGE OF SEMI SOLID :-
• Unless rapid in process method of analysis are developed. It is the usual practice to store the semi solid until the specified quality control test have been completed before packing into appropriate.
• Container :- tube, jar or single dose packets.
• A product is considered to be in process until it has been packaged.
• The active substance in the cream or ointment may react with the storage container unless a highly resistant stainless is used for bulk storage.
• Evaporation of water from a cream must be retarded : This can be effectively accomplished by placing non – reactive plastic sheeting in direct contact with the cream as well as covering the storage container with a tight fitting stainless -steel.
Transfer of material for packing :-
• The semi solid may be gravity fed if it is a two level operation or pumped to the filling equipment.
• It must be able to resists the shear stress developed in the transfer of the product as well as that due to the mechanical action of the filling equipment.
• Once a formula manufacturing procedure has been established there should be no deviation from it.
• The manufacturing and packing equipment should be sanitized following through cleaning with detergent.
• They should be flushed with chlorinated water formalin or other suitable sterilant followed by a bacteria free water.
• Water and swab sample should be taken to verify microbial elimination.
• Rigid foams :-
• Foams are system in which air or some other gas is emulsified in liquid phase to the point of stiffening.
• Eg. Shaving cream, aerosol shaving cream.
• Plasters :-
• They are solid or semi solid masses that adhere to the skin being applied in the form of piece of fabric that contains a layer of medication covered by a layer of adhesive.
• They are mainly used to
• Afford protection and mechanical support.
• Furnish an occlusive and macerating action.
• Bring medication into close contact with the surface of the skin.
• Example :- medicated pain relief plasters.
• Paste :-
• Pastes are basically ointment into which a high percentage of insoluble solid (granular material in a background fluid ) dispersion in an aqueous or fatty vehicle.
• They are usually prepared by incorporating solid directly into a congealed system by levigation with a porlion of the base to form a paste like mass.
• Paste are less greasy and less penetrating than ointment and do not flow at body temp.
• Like ointment, pastes, forms an unbroken relatively water impermeable film, but unlike ointment the film is opaque and therefore an effective uv light of sun.
• Example :- fatty paste e.g. zinc oxide paste, toothpaste, mustard
• Gels :-
• A semi solid dispersion system containing a gelling agent in sufficient quantities to impart a 3 dimensional polymeric matrix.
• Provide a cooling sensation when applied to the skin.
• Usually translucent and non greasy.
• They are used for medication and lubricant.
Creams :-
• A cream is a topical preparation usually for application to the skin.
• Creams for application to mucus membranes such as those of the rectum or vagina are also used. Cream may be considered pharmaceutical products as even cosmetic cream are based on technique developed by pharmacy and un- medicated cream are highly used in a variety of skin conditions.
• The function of a skin cream is to protect the skin against harshness from the environment and any dry conditions of the skin.
• A skin cream should aid the skin in carrying out its normal function that is restoring moisture to dry skin.
• Type of creams
1. Oil in water :- o/w Cream which are composed of small droplets of oil dispersion in a continuous aqueous phase. Example is vanishing Cream.
2. Water in oil :- W/O cream which are composed of small droplets of water dispersed in a continuous oil phase. Example is cold cream.
Use of Cream :-
• The provisions of a barrier to protect the skin.
• This may be a physical barrier or a chemical barrier as with sunscreen.
• To aid in the retention of moisture
• Cleansing
• Emollient effect
• As a vehicle for drug substance such as local anaesthetic, anti inflammation, hormone, anti biotics, anti fungal, or counter irritants.
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