PHT351 Sterile Dosage Form

Sterile Dosage Form Parentral Preparations. Ophthalmic Preparations.

Methods of Sterilization. Sterility Testing. Pyrogen Test.

Sterilization Sterilization: A Sterile Product: It is the process that kills or removes all living microorganisms including bacterial endospores. A Sterile Product: It should be free from all living microorganisms.

Sterilization Bacterial endospores are more resistant ( Why? ) Low water content and low metabolic activities. Thick spore coat. Presences of heat resistant chemicals such as diplocolinic acid and dicarboxylic acid.

Methods of Sterilization Heat Sterilization Cold Sterilization Dry Heat Moist Heat Radiation Toxic gases Filtration

Heat Sterilization Used only for Thermostable materials Mode of Action: Evaporation of water leading to increase conc. of electrolyes within the cells causing toxic effects. Denaturation of proteins such as enzymes. Leakage of plasma membrane.

Heat Sterilization Dry Heat: Incineration: ( Flaming ) Example: Flaming of inoculating loop. Hot air oven: Sterilization temperature: 160 180oC for 1 – 2 hrs. Used for: glass wares, metals, unhydrous powders, oils and waxes.

Heat Sterilization Moist Heat: Autoclaving: depends on the use of moist heat under pressure. Sterrilization temperature: 121oC for 15 – 20 min. Used for : glass wares, metals, such as surgical instruments and culture media. It has the advantage of less temperature and shorter time. i.e: less destructive to materials.

Cold Sterilization Used only for Thermolabile materials I. Radiation: Ionizing Radiation: ( δ-radiation ) Mode of action: It cause ionization of cell constituents leading to formation of free radicals which are highly toxic to the cell. Used for: Plastic items such as Petri-dishes, pharmaceutical containers, syrings, surgical gloves, dressings and sutures.

Cold Sterilization Used only for Thermolabile materials I. Radiation: Nonionizing Radiation: (UV radiation ) Mode of action: It cause only excitation of DNA leading to bond breakage and reformation of DNA Disadvantage: It has low penetration power. So, used only to reduce microbial load of air in rooms and areas wanted to be disinfected

Cold Sterilization II. Using of toxic gases: Such as Ethylene oxide, Propylene oxide and Formaldehyde. Used for: Plastic items such as Petri-dishes, pharmaceutical containers, syrings, surgical gloves, dressings and sutures. * The most important step in gas sterilization is the removal of the toxic gas.

Cold Sterilization III. Filtration: Used for thermolabile fluids such as vitamines, hormones and some ophthalmic solutions.

Bacterial Filter

Cold Sterilization III. Filtration: Types of Filters: Asbestos, Porcelain filters: Thick and porous material. Disadvantage: Having no unique pore size, So do not give 100% efficiency. Membrane Filters: Made of polymers of cellulose acetate or cellulose nitrate. Advantage:Thin, having a pore size of 0.4µm. Disadvantage: viruses and Mycoplasma (which having no cell wall) can pass through these filters

Test for the Efficiency of the Sterilization Processes Autoclave: Klintex Paper. Klintex bars. Bacillus sterothermophilus (biological indicator).

Test for the Efficiency of the Sterilization Processes Bacterial Filter: using a broth culture of Serratia marcescens It is the smallest bacteria ( 0.75 µm diameter). Produce red pigment at 25oC.

Test for the Efficiency of the Sterilization Processes Bacterial Filter: Procedure: 1.Filter a broth culture of Serratia marcescens through the membrane filter 2. Aseptically, place the membrane filter by means of sterile forceps on the surface of a nutrient agar plate. 3.Incubate the plate and the filtrate at 25oC for24 hrs.

Test for the Efficiency of the Bacterial Filter Results: If the filtrate show no growth of Serratia marcescens ( no red pigment ), While there is a growth of red colonies on the surface of the membrane filter. This will means that the filter is efficient.

Thank you كل عام وأنتم بخير With my Best Wishes,,, Manal Abu El-Khair