Chlorhexidine and Surfactants Quiz
30 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What effect do multivalent cations have on activity?

  • They enhance stability instead.
  • They increase activity significantly.
  • They reduce activity. (correct)
  • They have no effect on activity.

    • Which of the following substances can reduce activity when heated with methylcellulose?

  • Cations
  • Solvents
  • Anionic surfactants (correct)
  • Hydrophobic agents

    • What is the impact of heating in the presence of anionic surfactants?

  • It increases solubility.
  • It reduces activity. (correct)
  • It maintains activity.
  • It prevents degradation.

    • Which cations are specifically mentioned as reducing activity?

    <p>Mg2+ and Ca2+ (A)</p> Signup and view all the answers

    How does activity change in the presence of anionic surfactants?

    <p>Activity is reduced. (C)</p> Signup and view all the answers

    What is the concentration at which chlorhexidine acetate or gluconate is typically used?

    <p>0.01% w/v (C)</p> Signup and view all the answers

    Which substance enhances the antibacterial activity of chlorhexidine?

    <p>Aromatic alcohols (D)</p> Signup and view all the answers

    Which of the following substances decreases the antibacterial activity of chlorhexidine?

    <p>Anionic surfactants (A)</p> Signup and view all the answers

    What role does disodium edetate play in the activity of chlorhexidine?

    <p>It enhances the activity (B)</p> Signup and view all the answers

    Which statement about chlorhexidine's antibacterial activity is accurate?

    <p>Its activity decreases with the presence of anionic surfactants. (B)</p> Signup and view all the answers

    What is the primary use of benzalkonium chloride in the context described?

    <p>To enhance the transcorneal passage of non-lipid-soluble drugs (C)</p> Signup and view all the answers

    Which type of drugs does benzalkonium chloride primarily enhance the passage for?

    <p>Non-lipid-soluble drugs (C)</p> Signup and view all the answers

    In which of the following scenarios would benzalkonium chloride be particularly beneficial?

    <p>Using an ophthalmic formulation containing carbachol (B)</p> Signup and view all the answers

    How does benzalkonium chloride affect drug delivery?

    <p>It enhances the surface activity leading to better transcorneal delivery (D)</p> Signup and view all the answers

    Which of the following statements about benzalkonium chloride is incorrect?

    <p>It is a lipid-soluble compound. (B)</p> Signup and view all the answers

    Which of the following active ingredients requires protection?

    <p>Adrenaline (epinephrine) (C)</p> Signup and view all the answers

    What is the role of sodium metabisulphite in ophthalmic products?

    <p>It serves as an antioxidant (A)</p> Signup and view all the answers

    What is the carbon dioxide reaction in sulfite antioxidation?

    <p>2SO3 2- + O2 -&gt; 2SO4 2- (A)</p> Signup and view all the answers

    Which method is NOT used for sterilization of ophthalmic products?

    <p>Exposure to ultraviolet light (A)</p> Signup and view all the answers

    What is the purpose of using a 0.22 µm pore size membrane filter?

    <p>To ensure microbial sterilization (A)</p> Signup and view all the answers

    What is a potential consequence of prolonged usage of certain eye drops?

    <p>Intraocular deposition of mercury (A)</p> Signup and view all the answers

    What is the tolerated tonicity range for eye drops according to practical usage?

    <p>0.7–1.5% w/v sodium chloride (A)</p> Signup and view all the answers

    Which of the following correctly describes a condition that can arise from inappropriate eye drop usage?

    <p>Intraocular deposition of mercury (B)</p> Signup and view all the answers

    Why should certain eye drops not be used for prolonged periods?

    <p>They risk causing intraocular deposition of mercury (A)</p> Signup and view all the answers

    What is a safe characteristic of eye drops that ensures they are well tolerated by the eye?

    <p>Correct tonicity range (B)</p> Signup and view all the answers

    What type of airflow conditions are required for filling procedures?

    <p>Grade A laminar airflow conditions (B)</p> Signup and view all the answers

    At what temperature and duration is dry-heat sterilization employed for non-aqueous preparations?

    <p>160 C for 2 hours (A)</p> Signup and view all the answers

    Which of the following types of preparations typically undergo dry-heat sterilization?

    <p>Non-aqueous preparations (B)</p> Signup and view all the answers

    Which of the following statements is true regarding filling procedures?

    <p>Filling should take place under Grade A laminar airflow conditions. (A)</p> Signup and view all the answers

    Why is dry-heat sterilization used for certain pharmaceutical preparations?

    <p>It is suitable for materials that cannot withstand moisture. (A)</p> Signup and view all the answers

    Flashcards

    Multivalent Cation Inhibition

    The reduction in activity of a substance in the presence of ions with multiple positive charges (like Mg2+ and Ca2+).

    Methylcellulose Inhibition

    The ability of a substance to function is decreased when heated with methylcellulose.

    Anionic Surfactant Inhibition

    The ability of a substance to function is decreased when formulated with negatively charged substances (like surfactants).

    Surfactant

    A substance that can affect the behavior of other substances, especially by increasing their surface area.

    Signup and view all the flashcards

    Multivalent Cations

    Ions with multiple positive charges, like magnesium (Mg2+) and calcium (Ca2+).

    Signup and view all the flashcards

    Mercurialentis

    The buildup of mercury in the lens of the eye.

    Signup and view all the flashcards

    Tonicity

    The ability of a solution to resist changes to its osmotic pressure.

    Signup and view all the flashcards

    Tolerable tonicity range for eye drops

    A range within which eye drops can have a concentration of sodium chloride without significantly affecting the eye's osmotic pressure.

    Signup and view all the flashcards

    Prolonged usage eye drops

    Eye drops that are used for extended periods of time.

    Signup and view all the flashcards

    Mercury deposition in the eye

    The potential risk of mercury accumulation in the eye due to prolonged use of eye drops containing mercury.

    Signup and view all the flashcards

    Surface Activity of Benzalkonium Chloride

    Benzalkonium chloride's ability to interact with and modify the surface properties of a substance, particularly biological membranes like the cornea.

    Signup and view all the flashcards

    Transcorneal Passage

    The cornea is the clear outer layer of the eye, acting as a barrier for drugs.

    Signup and view all the flashcards

    Non-Lipid-Soluble Drugs

    Drugs that don't easily dissolve in fats, like carbachol, can benefit from increased transcorneal passage with Benzalkonium chloride's help.

    Signup and view all the flashcards

    Carbachol

    Carbachol is a medication used to treat certain eye conditions.

    Signup and view all the flashcards

    How Benzalkonium Chloride Enhances Drug Delivery

    Benzalkonium chloride can change the cornea's surface to help non-lipid-soluble drugs like carbachol reach their target more effectively.

    Signup and view all the flashcards

    What is chlorhexidine used for?

    Chlorhexidine acetate or gluconate is an antibacterial agent often used in oral hygiene and wound care.

    Signup and view all the flashcards

    What is the typical concentration of chlorhexidine?

    Chlorhexidine is typically used at a concentration of 0.01% w/v, meaning 0.01 grams of chlorhexidine per 100 milliliters of solution.

    Signup and view all the flashcards

    How can chlorhexidine's effectiveness be increased?

    Certain substances like aromatic alcohols and disodium edetate can enhance the antibacterial activity of chlorhexidine.

    Signup and view all the flashcards

    What can decrease the effectiveness of chlorhexidine?

    Anionic surfactants, like those found in some soaps, can reduce the effectiveness of chlorhexidine.

    Signup and view all the flashcards

    How does chlorhexidine's activity vary?

    Chlorhexidine's effectiveness can be influenced by the presence of certain substances, some of which can enhance its activity while others can diminish it.

    Signup and view all the flashcards

    Active ingredients in ophthalmic products

    Substances in eye drops that require protection from degradation.

    Signup and view all the flashcards

    Antioxidants in ophthalmic products

    Chemicals like sodium metabisulphite and sodium sulphite used to prevent oxidation and degradation of active ingredients in eye drops.

    Signup and view all the flashcards

    Role of sulfite in ophthalmic products

    Sulfite reacts with dissolved oxygen, removing it from the solution and thus preventing oxidation of active ingredients.

    Signup and view all the flashcards

    Autoclaving as a sterilization method

    A method to sterilize ophthalmic solutions by exposing them to high heat and pressure within a sealed container.

    Signup and view all the flashcards

    Filtration sterilization for ophthalmic products

    A method where ophthalmic solutions are passed through a filter with tiny pores to remove microorganisms.

    Signup and view all the flashcards

    Grade A Laminar Airflow

    A sterile environment created using a laminar airflow hood, designed to minimize contamination during pharmaceutical preparation.

    Signup and view all the flashcards

    Dry-Heat Sterilization

    A process of sterilizing heat-stable substances like liquid paraffin eye drops by exposing them to dry heat at a high temperature (160°C) for a specified time (2 hours).

    Signup and view all the flashcards

    Non-aqueous Preparation

    A type of pharmaceutical preparation that does not contain water.

    Signup and view all the flashcards

    Liquid Paraffin Eye Drops

    A substance like liquid paraffin that is used in eye drops.

    Signup and view all the flashcards

    Sterilization

    A method used to eliminate microorganisms and ensure sterility in pharmaceutical preparations.

    Signup and view all the flashcards

    Study Notes

    Ophthalmic Preparations

    • Ophthalmic preparations include eye drops, lotions, ointments, creams, gels, contact lens solutions, parenteral products, and ophthalmic inserts.
    • Eye drops are solutions, emulsions, or suspensions of active medications for the conjunctival sac.
    • Eye lotions are for irrigating and cleansing the eye surface, or for impregnating eye dressings.
    • Eye ointments, creams, and gels contain active ingredients for application to the lids.
    • Contact lens solutions are for contact lens care.
    • Parenteral products are for intracorneal, intravitreous, or retrobulbar injections.
    • Ophthalmic inserts release active ingredients over a prolonged period.
    • Powders are for preparing eye drops and lotions.

    Sterilization Requirements

    • All ophthalmic preparations must be sterile and free from foreign particles.

    Medicaments in Ophthalmic Products

    • Anaesthetics: used topically in surgical procedures.
    • Anti-infectives: antibacterials, antifungals, and antivirals.
    • Anti-inflammatories: corticosteroids and antihistamines (non-steroid).
    • Antiglaucoma agents: reduce intraocular pressure, such as beta-blockers.
    • Astringents: such as zinc sulphate.
    • Diagnostic agents: such as fluorescein, highlighting damage to the epithelial tissue.
    • Miotics: constrict the pupil and contract the ciliary muscle, increasing drainage from the anterior chamber.
    • Mydriatics and cycloplegics: dilate the pupil and paralyze the ciliary muscle, facilitating eye examination.

    Eye Drop Formulation

    • Active ingredient(s): to produce the desired therapeutic effect.
    • Vehicle: aqueous, but occasionally oil.
    • Antimicrobial preservative: to eliminate microbial contamination during use, maintaining sterility. Should not interact with active ingredients.
    • Adjuvants: adjust tonicity, viscosity, or pH.

    Antimicrobial Preservatives

    • Preservatives should be included in all eye drops except those formulated for intraocular surgery or those supplied as single-dose preparations (tear replacements).
    • Specific preservatives are suitable for specific eye drops (e.g., benzalkonium chloride and chlorhexidine acetate or gluconate).
    • Important preservation factors include concentration and stability at autoclaving temperatures in specific eye drops (such as those not requiring autoclaving, like single-use formulations).

    Benzalkonium Chloride

    • One of the most common preservatives in eye drops (over 70% of commercially produced eye drops).
    • Usually at 0.1% w/v.
    • A mixture of alkylbenzyldimethyl ammonium compounds.

    Benzalkonium Chloride - Activity

    • Stable to sterilization by autoclaving.
    • Rapid bactericidal action against Gram-positive and Gram-negative organisms.
    • Destroys external cell structures.
    • Activity reduced by multivalent cations (Mg2+, Ca2+).
    • Activity reduced by heating with methylcellulose or anionic surfactants.
    • Activity against Gram-negative organisms enhanced by chelating agents like disodium edetate.
    • Surface activity enhances transcorneal passage of non-lipid-soluble drugs.
    • Not suitable for preserving local anaesthetics; can abolish the blink reflex.

    Chlorhexidine Acetate or Gluconate

    • Cationic biguanide bactericide with antibacterial properties, similar to benzalkonium chloride.
    • Used at 0.01% w/v.
    • Antibacterial activity enhanced by aromatic alcohols and disodium edetate.
    • Activity reduced by anionic surfactants.

    Chlorobutanol

    • Used at 0.5% w/v.
    • MOA (mechanism of action) is unknown.
    • Main disadvantages: volatility, absorption by plastic containers, and lack of stability at autoclave temperatures.

    Organic Mercurials

    • Phenylmercuric acetate, nitrate, and thiomersal.
    • Used at low concentrations (0.001-0.004% w/v).
    • Marked absorption by rubber.
    • Should not be used in prolonged-use eye drops, because of intraocular mercury deposition.

    Tonicity

    • Eyes tolerate small volumes of eye drops with tonicities equivalent to 0.7-1.5% w/v sodium chloride.
    • Best equivalent to 0.9% NaCl.
    • Some preparations are hypertonic.

    Viscosity Enhancers

    • Increasing viscosity prolongs eye drop residence time, increasing drug penetration and therapeutic action.
    • Important for artificial tears.
      • Hydroxypropyl derivative of methylcellulose: the most popular cellulose derivative for enhancing viscosity.
      • Polyvinyl alcohol, Polyvinylpyrrolidone, polyethylene glycol, dextrin, and sodium hyaluronate.

    pH Adjustment

    • pH offers best stability during preparation and storage.
    • Also contributes to optimal therapeutic activity and patient comfort.
    • Lachrymal fluid pH is 7.2-7.4, with considerable buffering capacity.

    Buffers

    • Example of buffers in practice using pilocarpine and its ion in a pharmaceutical or biological system.

    Antioxidants

    • Primarily reducing agents.
    • Protect active ingredients.
      • Examples of active ingredients requiring protection: adrenaline, proxymetacaine, sulfacetamide, tetracaine, phenylephrine, and physostigmine.
    • Most used antioxidants: sodium metabisulphite and sodium sulphite.

    Sterilization of Ophthalmic Products

    • Methods: autoclaving (115-121°C), filtration (0.22 µm pore size), and dry-heat sterilization (160°C).
    • Critical aspects of sterilization methods like filtering and autoclaving to sterilize the materials and products.

    Instillation of Eye Drops

    • Procedure for administering eye drops: tilt head back, pull down lower eyelid to form a pouch, drop in the prepared pouch, don't touch the eye, release the eyelid, and avoid excessive blinking.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Ophthalmic Preparations PDF

    Description

    Test your knowledge on the effects of multivalent cations and surfactants on the activity of chlorhexidine. This quiz covers its antibacterial properties, the role of various substances in enhancing or reducing its activity, and specific concentrations used in practice. Assess your understanding of the interactions between these compounds!

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser