Topical Agents 3rd Year Pharmacy 2016 - 2017

Outline Classification a- protective b- antimicrobial agents A- protective products Talc , Zinc oxide ZnO, Calamine, Titinum oxide TiO2, Al products& silicon polymer Antimicrobials Mechanism 1-oxidation H2O2,ZnO,KMnO4, Iodine 2- Halogenations NaOCl 3- protein ppt AgNO3.

Protective Agents Protective Any agent that isolates the exposed surface from harmful or annoying stimuli Properties of protective agents: Insoluble in water Chemical Inertness Adsorbent

Deeper penetration of topical agents are also seen in many cases which are beneficial. (Penetration of antiseptics into the tissue  below the skin prevents the possibility of deeper infections)-

Protective Agents Talc Talc (Mg3Si4O10(OH)2 protective: native hydrous magnesium silicate, common name and chemical formula. Soapstone can be grinding in 80/100 mesh particle size. As grease touch., insoluble in water, Uses as protective agents , as lubricants and in  pharmaceuticals, as cosmetics, ceramics,  for plastic cloves,

Zinc Oxide ( ZnO ) White or fait yellow color powder, insoluble in water. Other formulation as Zinc Oxide ointment for adult, & Zinc Oxide in Glycerin for children. Dusting powder, used astringent and protective topical agent, mild antiseptic, used in the acne preparation, eczema,& psoriasis It is usually used in the manufacture of plasters.

Calamine ZnO and Fe2O3

It used as dusting powder, lotions, ointments, as smoothing agents, for sunburn, eczema, urticaria. Calamine lotion is very popular.

Boric Acid H3BO3 Is a weak acid, used as antiseptic, and as chemical precursor for many reactions. Uses: 1- Antiseptic 2- dilute solution for eye wash 3-Acne 4- Vaginal douche against bacteria. 5-It used as protective against athlete foot.

Titanium dioxide TiO2 Topical protective agents as cream is used against sunscreen to protect the skin aganist ultra-violet light ( U.V.). The organic topical protective agents is P-aminobenzoic acid ( PABA) .

Antimicrobial Agents Antiseptic: Any agent which kills or inhibits the growth of microorganisms found in living tissue. Disinfectant: Any agent which kills or inhibits the growth of microorganisms found in inanimate objects. Germicide: General term for fungicide, bactericide, amoebicide

Mechanisms of action of antimicrobials There are THREE proposal mechanisms: 1-Oxidation 2-Halogenation Protein Precipitation3-

Oxidation cell membrane of bacteria SH SH S---S

Halogenation the protein of the cell membrain H2N CHR CO NH CHR1--- (HOCl) NaOCl H2NCHRCONCl CHR!...

Protein pption that kill the microbe H2NCHR1CONHCHR2---- AgNO3 H2NCHR1CONHCHR2--- Ag

Hydrogen Peroxide H2O2 liquid not store in glass bottles because it decompose ,it store in white plastic container, keep in cold dark place to prevent decomposition. There are many uses : 1- Antiseptic for wash wound , teeth and ear 2-Bleaching color ( hair ). 3- Laundry for cloths.

Sodium Perborate Antimicrobial:  Composite of H2O2, NaBO2 and NaOH Used as bleaching agent in non-chlorine laundry bleaches

Potassium Permanganate KMnO4 Chemically is a strong oxidizing agent, solid purple crystalline , odorless. Store in well closed container. Uses: 1- Oxidizing agent for skin disease in different concentrations 1: 5000, 1:15000 2- used in swimming pool for athlete foot. 3- Strong oxidizing for many organic reactions.

Iodine I2 It is dark violet ,insoluble in water , but the I2 + KI = I3 – Complex soluble in water as iodine solution, soluble in alcohol known as tincture iodine Iodine solution weak solution ( 25g I2 + 25g KI ) in 100ml And strong solution ( 50g I2 + 50g KI ) in 100 ml. Iodine preparations and compounds Antimicrobial property due to oxidation and Iodination disinfectants A chemical reagents in analytical reagent. In drug synthesis. In Povidin iodine as new product.

Povidone Iodine ( PVP – I) is a stable chemical complex of poly vinyl pyrrolidine iodide. It is broad spectrum antiseptic for wounds. It is used disinfectant .

2- Halogenation Dakin's Solution Sodium hypochlorite solution, (usp)  Contains 4-6% of NaOCl, It is made from bleach that has been diluted and treated to decrease irritation. Chlorine, the active ingredient in Dakin's solution, is a strong antiseptic that kills most forms of bacteria and viruses..

3- Protein ppt (Silver Nitrate AgNO3) Prepare as 1% AgNO3 , protective from light due to oxidation. Effective against gonococcal organism. Antimicrobial activity of these compounds is due to protein precipitant action. 1% used eye newborn babies.