Pharmaceutical Preparations II Review Exercises

I. Displacement Value

• Displacement value of a substance relative to an excipient: is the amount of excipient that occupies the same volume as 1 g of that substance when molded.

Note:

• Displacement value only applies to solid substances.

• Displacement value helps determine the amount of excipient needed to replace 1 g of solid in a formula.

II. Dispersed Systems

• Microheterogeneous system: A dispersed system with a dispersed phase size of about 50 μm.

Note:

• Microheterogeneous systems are usually heterogeneous dispersed systems.

• The size of the dispersed phase can vary depending on the type of microheterogeneous system.

III. Emulsions

• Crude emulsion: Has a droplet size of about 0.1-50 μm.

• Microemulsion: Has a droplet size of about 10-100 nm.

Note:

• The smaller the droplet size, the more stable the emulsion.

• Microemulsions have a larger surface area than crude emulsions, so they have higher absorption potential.

IV. Distinguishing between Suspensions and Emulsions

• Easiest to identify: the state of the dispersed phase.

Note:

• Suspension: A heterogeneous dispersed system where the dispersed phase is solid and the continuous phase is liquid.

• Emulsion: A heterogeneous dispersed system where the dispersed phase is liquid and the continuous phase is liquid.

V. Excipients

• Xanthan gum: Often used as a suspending agent for liquid suspensions.

• Bentonite: Forms emulsions depending on the order of mixing:

• Dispersion in water first => more water-absorbing and vice versa.

Note:

• Xanthan gum is a type of polysaccharide with good gel-forming and water-holding properties.

• Bentonite is a type of clay with the ability to absorb water and form emulsions.

VI. Preparation Methods

• Direct saponification method: Used to prepare O/W emulsions (oil in water) from oil and alkali.

• Example: Crude peanut oil 5 g, limewater 5 g.

• Adding the external phase to the internal phase (dry gum method): Used to prepare suspensions, emulsions by adding the external phase to the internal phase that has been emulsified.

• Example: Mineral oil 50 ml, simple syrup 10 ml, vanillin 4 mg, purified water qs 100 ml.

• Ratio of phases in the dry gum method: 4 oil: 2 water: 1 gum.

Note:

• The dry gum method is often used in the preparation of O/W emulsions.

• The phase ratio can vary depending on the type of emulsion and the excipients used.

VII. Emulsion Type

• Double emulsion type: Can be identified using a microscope.

• Coalescence of particles in emulsions: Can be accelerated by centrifugation or thermal shock.

• Uniformity of particle size: Directly affects the phenomenon of coalescence or crystallization.

Note:

• Double emulsions are emulsions with a complex structure, where the dispersed phase is an emulsion.

• Coalescence or crystallization is an undesirable phenomenon in suspensions, emulsions, as they can alter the properties of the product.

VIII. Liquid Medications

• Formula: Bromoform 2 ml, sodium benzoate 4 g, codeine phosphate 0.2 g, simple syrup 20 g, purified water qs 100 ml.

• Dosage form: Emulsion potion.

• Structure: Emulsion.

• Disadvantage: Irritates the mucous membrane.

• Additions to the formula:

• Peanut oil: Decreases the density of the oil phase.

• Gum Arabic: Emulsifies oil.

Note:

• Emulsion potion is a type of liquid medication with an emulsion structure.

• Liquid medications can irritate the mucous membrane if not carefully formulated.

IX. Ointments

• Formula: Paraffin oil 500 ml, gum Arabic 50 g, tragacanth gum 2.5 g, gelatin 7.5 g, lemon oil 1 ml, vanillin 0.2 g, sodium benzoate 1.5 g, glycerol 50 ml, water qs 1000 ml.

• Preparation method: Dry gum method combined with wet gum method/ wet gum method (depending on the amount of emulsion + equipment).

• Unreasonable combination: Combining paraffin oil with a mixture of gum Arabic, tragacanth gum, and gelatin, then adding water to mix into a thick emulsion.

• Role of sodium benzoate in the formula: Preservative.

Note:

• Ointments can be prepared using various methods.

• The way excipients are combined can affect the properties of the ointment.

X. Classification of Ointments

• Classification by structure: Ointments belonging to homogeneous dispersed systems and ointments belonging to heterogeneous dispersed systems.

Note:

• Homogeneous ointment: An ointment with a uniform structure, where the dispersed phase is completely dissolved in the continuous phase.

• Heterogeneous ointment: An ointment with a non-uniform structure, where the dispersed phase is not completely dissolved in the continuous phase.

XI. Percutaneous Absorption

• Order of layers in the epidermis: Protective lipid layer -> Stratum corneum -> Rein barrier region -> Mucosa layer.

• Skin layer where capillaries begin: Dermis.

• Correct statement: Removing the protective lipid layer on the skin surface helps increase the penetration and absorption of the drug.

Note:

• The stratum corneum is the main protective layer of the skin, preventing the penetration of substances.

• The dermis is the layer with capillaries, where the drug can be absorbed into the bloodstream.

XII. Excipients in Ointments

• Anhydrous lanolin: Often combined with petrolatum (5-50%) to adjust consistency.

• Glyceryl monostearate: Combined with sodium lauryl sulfate will increase emulsification ability and suitable for O/W emulsions with pH < 7.8.

• Formula: EDTA ………………………. 0.05 g, Salicylic acid …………….. 2 g, Carbopol 940 ……………… 4 g, Purified water ……………………. qs 100 g.

• Reasonable additions to the formula: (Mono-, Di-) Triethanolamine.

Note:

• Anhydrous lanolin is an oil-based excipient with emulsification ability.

• Glyceryl monostearate is an oil-based excipient with emulsification and gel-forming abilities.

• Triethanolamine is an excipient that helps adjust the pH of ointments.

XIII. Structure of Ointments

• Formula: Salicylic acid …………….. 30 g, Benzoic acid ……………… 60 g, Emulsifying excipient ………… 910 g.

• Structure: Suspension.

• Formula: Copper sulfate ………………… 0.3 g, Zinc sulfate …………………. 0.5 g, Water …………………………. 30 g, Lanolin ……………………… 50 g, Petrolatum ……………………… 100 g.

• Structure: N/W type emulsion.

Note:

• Suspension: A heterogeneous dispersed system where the dispersed phase is solid and the continuous phase is liquid.

• Emulsion: A heterogeneous dispersed system where the dispersed phase is liquid and the continuous phase is liquid.

XIV. General Quality Requirements for Ointments According to Vietnamese Pharmacopoeia IV

• Except: Sterility testing.

Note:

• Ointments must meet the requirements for uniformity, mass uniformity, and other technical requirements.

• Ointments do not require sterility testing, as they are usually used topically.

XV. Forms of Ointments

• Simple ointment: Lanolin 10 parts, Petrolatum 90 parts.

• Structure type: Solution.

• Dalibour ointment: Emulsion type.

• Silver sulfadiazine ointment: Does not belong to any of the above forms.

Note:

• Solution: A homogeneous dispersed system where the dispersed phase is completely dissolved in the continuous phase.

• Emulsion: A heterogeneous dispersed system where the dispersed phase is liquid and the continuous phase is liquid.

XVI. Other Excipients

• PEG: Can dissolve both water-insoluble substances and oil-insoluble substances.

• Spermaceti: Obtained from the head cavity of sperm whales and mainly composed of fatty acid esters with high fatty alcohols.

• Plastibase: Formed by dissolving polyethylene with a molecular weight of about 21000 at a ratio of 5% in petrolatum at 130 degrees, then quickly cooled to crystallize and form a gel.

Note:

• PEG is a water- and oil-based excipient with gel-forming ability.

• Spermaceti is a type of wax with oil-based properties.

• Plastibase is an oil-based excipient with gel-forming ability.

XVII. Complete Emulsifying Excipients

• Formula: Oleic acid 5 g, Peanut oil 320 g, Lanolin 80 g, Calcium hydroxide solution qs 1000 g.

• Excipient type: Complete N/W emulsifying excipient.

• Formula: Stearic acid 240 g, 30% NaOH solution 30 g, Glycerin 280 g, Purified water 550 ml.

• Excipient type: Complete O/W emulsifying excipient.

Note:

• Complete N/W emulsifying excipient: An excipient with the ability to form water-in-oil (N/W) emulsions.

• Complete O/W emulsifying excipient: An excipient with the ability to form oil-in-water (O/W) emulsions.

XVIII. Preparation Methods for Ointments

• Ointment formula: Ketoprofen 2.5 g, Propylene glycol 15 g, Nipagin 0.1 g, Gel excipient qs 100 g.

• Preparation method: Dissolution method.

Note:

• Dissolution method: Used to prepare ointments by dissolving the active ingredient in the excipient.

XIX. Suppositories and Inserts

• Correct statement about suppositories: Depending on the purpose of use, the medication may have local or systemic effects.

• Correct statement about urethral inserts: Only have local (antiseptic) effects.

• Characteristics of medications absorbed through the vaginal mucosa: The medication can be absorbed into the bloodstream and is not metabolized first-pass through the liver.

• The presence of surfactants in the composition of inserts: May increase drug absorption through the rectal mucosa.

• Physicochemical structure of suppositories and ovules: Solution, suspension, emulsion.

• Physiological factors affecting drug absorption through the rectal route: Blood flow through the rectum, rectal fluid, pH of rectal fluid, rectal motility, mucus layer.

• Advantages of suppositories over oral medications: Can be used for patients in a coma.

• Disintegration time of suppositories prepared with PEG excipient: Not more than 60 minutes.

• Good drug absorption through the rectal mucosa depends mainly on: The physicochemical properties of the drug and excipient used.

• Suppositories prepared with Witepsol release the active ingredient through the mechanism: Melting at body temperature.

• PEG excipient used in the preparation of inserts belongs to the group of excipients: Synthetic water-based gel.

• Formula: Colargol 0.2 g, Witepsol qs 1 suppository.

• Structure: N/W emulsion.

Note:

• Suppositories and inserts are dosage forms used to administer medication into the rectum or vagina.

• Suppositories can have local or systemic effects.

• Inserts mainly have local effects.

XX. Powders

• Moisture content of powder should not exceed: 9%.

• Measure that does not increase the flowability of the powder mass: Reduce the particle size.

• Incorrect principle of powder mixing: Add colored substances first.

• Excipient present in granules but not in powders: Adhesive.

• Formula for a powder containing: Precipitated sulfur, ZnO2, paraffin oil, talc powder. Which excipient should be added? Magnesium carbonate.

• For the powder formula containing: Pharmaceutical sodium sulfate and magnesium sulfate, what should be noted? Replace the hydrated crystalline salt form with the anhydrous form.

• When grinding a substance with strong oxidizing properties, choose: Glass mortar.

• Grinding machine with heavy balls performs solid grinding through the mechanism: Impact and grinding.

• In an external powder prescription, if there is a eutectic incompatibility that melts and moistens the powder, it can be overcome by: Using an inert powder to isolate the incompatible substances.

• If there is too much alcohol tincture or extract in the powder formula, it can be overcome by:

• Evaporating the solvent (if the drug is heat-stable).

• Replacing the liquid tincture or extract with a solid or dry extract.

• The amount of liquid (if any) in powder should not exceed: Not more than 10% compared to the solid drug.

• The amount of alcohol tincture or liquid extract in a powder prescription is considered small, and can be prepared as usual when: Not more than 2 drops/1 g.

• Single-dose powder: Packaged in single doses.

Note:

• Powders should ensure moisture content, uniformity, and flowability.

• Incompatibilities may occur between components in powders, which should be noted and overcome.

XXI. Granules

• Methods of preparing granules:

• Dry granulation

• Wet granulation

• Fluid bed granulation

• Spray drying

• Classification of tablets according to use and route of administration: Regular tablets and special tablets.

• Classification according to drug release characteristics:

• Immediate release tablets

• Modified release tablets

• Controlled release tablets

Note:

• Granules are solid dosage forms, easy to swallow, often used for children.

• Tablets are solid dosage forms, easy to swallow, easy to manufacture, and widely used.

XXII. Tablets

• According to the Pharmacopoeia, for regular tablets, the amount of drug dissolved in … must reach …. of the active ingredient stated on the label: 45 minutes, at least 70%.

• Active ingredients unstable in acidic environments, irritating to the stomach, such as: aspirin, diclofenac, serrathiopeptidase enzyme are often formulated in the form of: Modified release tablets.

• Advantages of tablets, EXCEPT: High bioavailability.

• For tablets to meet quality standards, two important conditions are:

• Adhesion of powder and granules.

• Compacting force of the machine.

• Which factor of granules affects: adhesion, flowability, hardness, and stability of the tablets: Moisture content.

• Which factor of granules affects the weight uniformity and content uniformity of tablets: Flowability.

• In the process of tablet formation, powder and granules go through three states:

• Deformation.

• Elastic recovery.

• Shaping.

• Suitable preparation method for effervescent tablets containing Paracetamol – Vitamin C: Granulation combined with wet granulation.

• Disintegration time of fast-dissolving or fast-dispersing tablets: 3 minutes.

• Which property is the most important and characteristic of granules for tabletting: Compressibility of granules.

• Reasons for uneven tablet surface:

• Punch erosion.

• Granules are too moist.

• The color of granules and lubricating excipient are different.

• Advantages of eccentric tablet presses, EXCEPT: High capacity.

Note:

• Tablets must ensure disintegration time, weight uniformity, hardness, and stability.

• Tablets can be prepared using various methods, depending on the type of tablet and the properties of the active ingredient.

XXIII. Excipients in Tablets

• Lubricating or polishing excipient: Promotes sliding, prevents sticking, lubricates, polishes.

• The amount of essential oil in tablets is usually around … percent of the tablet weight: 0.5%.

• Main groups of excipients always present in the composition of tablets: Diluent, binder, disintegrant, lubricant.

• Calcium carbonate, magnesium carbonate, magnesium oxide, kaolin … belong to which characteristic group of excipients: Absorbent excipients.

• Spray granulation technique: Granulation using spray drying.

Note:

• Lubricating excipients help tablets slide easily out of the tablet press, preventing sticking to the mold.

• Absorbent excipients help absorb moisture, creating hardness for tablets.

XXIV. Coated Tablets

• Structure of coated tablets: Two parts: the core containing the active ingredient and the coating layers usually containing only excipients.

• Coated tablets are prepared by conventional techniques and equipment: Sugar coating or powder coating using a coating pan.

• The thickest coating layer is in the form of medication: Classic sugar-coated tablets.

• The thinnest coating layer is in the form of medication: Film-coated tablets.

• The core retains almost its shape and markings if suitable techniques are used: Film coating using a fluid bed coating machine.

• Enteric-coated tablets: No sign of disintegration in the stomach after 2 hours and disintegration in the intestine after 60 minutes.

• Among the types of tablets, the tablet with the least abrasion, e.g. ≤ 0.2%, is: Tablets for coating – core tablets.

• Excipient used as a frame, base for sugar-coated tablets: RE sucrose or syrup with suitable concentration.

• Solution to overcome the impact of gravity on tablet surface abrasion and uneven coating layer: Coating using an oval coating pan, tilted at 45 degrees.

• Thin film coating with water-soluble excipients or a mixture of solvents with water aims to: Reduce cost due to expensive organic solvents, avoid toxicity and risk of fire and explosion.

• Weight uniformity testing requirement: Film-coated tablets.

• Disintegration testing is not required for: Chewable tablets.

• Number of stages in the sugar coating process: Protective coating, base coating, smoothing coating, color coating, polishing.

• Film coating for tablets can be similar to the technique performed in the stage: Protective coating, moisture-proofing with zein excipient, red gum in sugar coating.

• Tablet compression (dry coating) can use: Double-compression tablet press, special-purpose machine.

• Colors used for coated tablets are: Colors permitted by the Ministry of Health.

• Apply for coating suppositories, coating pills with beeswax, solid paraffin: Coating by dipping.

• Components of film coating solution: Film-forming substance, solvent, plasticizer.

• Dissolution and release of active ingredients in coated tablets, can be investigated by the method applied to: Tablets, pills.

Note:

• Coated tablets are dosage forms with a coating layer on the outside of the core, helping to protect the active ingredient, mask taste, and improve appearance.

• Coated tablets can disintegrate in the stomach or intestines, depending on the type of coating and purpose of use.

XXV. Microparticles

• Benefits of microparticles:

• Control the rate of drug release.

• Protect the integrity of the drug, leading to higher bioavailability than conventional dosage forms.

• Control the location of drug release.

• Help protect biological preparations.

• Complex flocculation method for microparticle formation belongs to the group of methods: Physicochemical.

• Which microparticle formation method has a core (capsule) structure: Surface polymerization and solvent evaporation.

• Which microparticle formation method has a matrix (matrix) structure: Simple flocculation method and complex flocculation method.

• Which microparticle preparation method starts with monomers: Surface polymerization.

• Polymers used in the flocculation method must be: Water-based.

• Solvent evaporation method, the first step requires the preparation of … (a) … or … (b) …. The polymer for forming the capsule shell must dissolve in … (c) ….: N/W, suspension of solid dissolved in oil, DMHC.

• Methods for testing the size and properties of microcapsules:

• Sieving method.

• Scanning electron microscopy (SEM).

• Laser diffraction spectroscopy (LDS).

• Differential scanning calorimetry (DSC).

• Bloom value is used to assess the property of gelatin gel used as a capsule shell: Polymer cross-linking.

Note:

• Microparticles are dosage forms with a small size, from 1-1000 µm, helping to control the rate of drug release, increase bioavailability.

• Microcapsules are dosage forms with a shell enclosing the active ingredient, helping to protect the active ingredient, mask taste, control the rate of release.

XXVI. Soft Capsules

• Which of the following is not used as a dispersion medium in the drug mass of soft capsules: Ethyl alcohol.

• To carry out filling soft capsules in the form of a suspension, if the solid drug is lipophilic, the wetting agent should be used: Lecithin.

• In the drop-filling method for soft capsules, there is an incorrect step: Cooling the capsules in cold water at 4 °C.

• Fine powder active ingredients, lipophilic, can be put into soft capsules in the form of: Suspension in oil.

• The drug mass in soft capsules should have a pH of around: 2.5 – 7.5.

• In the production of hard capsule shells, to ensure shell uniformity, which component can be added to the gelatin solution: Only need to control the concentration and temperature of gelatin.

• The disadvantage of the compression method for soft capsule formation is: The capsule has a ridge around it.

• The ratio of glycerin to solid gelatin in hard capsule shells is: 0.4: 1.

• Which of the following methods is not used to prepare capsules: Dispersion method.

• 1 ml corresponds to … minim: 16.23 minim.

• Hard capsules consist of … main components: 3.

• What is BAV (Base Absorption Value): The number of grams of liquid substance needed to mix with 1 g of drug to form a drug mass with suitable flowability for capsule filling.

• Average moisture content of soft capsule shells: 6 – 10%.

• The maximum weight of soft capsules produced by the drop-filling method is: 0.75 g (20 – 750 mg).

• The Bloom value of gelatin used to prepare soft capsules is: 100 – 200 Bloom grams.

• In the technique of preparing soft capsules by the drop-filling method, the drug mass inside should have a viscosity of about: 1 – 130 cps.

• The method of filling soft capsules with the highest productivity is: Compression on a rod method.

• Plasticizers commonly used in the production of soft capsule shells: Glycerol, sorbitol.

Note:

• Soft capsules are dosage forms containing solid, liquid, or suspension active ingredients, enclosed in a soft gelatin shell.

• Soft capsules have the advantage of being easy to swallow, masking taste, and controlling the rate of release.

XXVII. Aerosol Dosage Form

• The dosage form with the drug in the form of a colloid, liquid, with high viscosity: Aerosol spray.

• Aerosols containing adrenaline belong to the type: Aerosol spray.

• Aerosols containing hydrocortisone belong to the type: Aerosol fog.

• Sol-gas is: A type of heterogeneous dispersion of countless fine particles suspended in the air.

• Inhalations: Are dosage forms in solid or liquid form.

• Liquid dosage form in a closed container, with propellant at high pressure, in which there is a certain amount of gas evenly dispersed in the liquid environment to create foam, when used, the foam spontaneously breaks down due to gas escaping, leaving the drug in a soft form that easily adheres: Foam medication.

• 3-phase state of aerosol: Formed when using compressed liquefied gas.

• Crude aerosol: Used in the treatment of upper respiratory tract diseases.

• Active ingredients used in dry powder inhalers, except: Theophylline.

• Classification of aerosols by aerosol generation technique, which type of aerosol cannot be used by patients themselves, but must be used at a healthcare facility? Aerosols generated by air compressors.

• Aerosols have a suspension/ solution/ emulsion structure when: Stored in a static state.

• Components of an aerosol canister consist of 3 parts: Medication, container & nozzle, propellant.

• “Compressing the medication through the nozzle, creating a dispersed system of drug particles in the air” is the role of: Propellant.

• Complete aerosol is: Aerosol that has been filled with compressed gas.

• Aerosol container made of aluminum, should be noted: Varnish the inside surface to protect it.

• 2 most important properties of propellants: Good expansion and safety.

• Liquefied gas used in aerosols: Stable if there is water present.

• The role of dimethyl ether in propellants: Increases the solubility of water-soluble active ingredients.

• Propellants that deplete the ozone layer: CFCs.

• Difference between the cold process and the high pressure-high temperature process: The order of the two steps of valve placement, gas filling. The cold process places the valve later, the high-temperature process fills the gas later.

Note:

• Aerosols are dosage forms that deliver medication to the respiratory tract.

• Aerosols come in many different forms, depending on the type of active ingredient and the purpose of use.

XXVIII. Incompatibilities

• When the powder formula contains Anesthesin, Sulfanilamide, incompatibility occurs due to: Anesthesin reduces the effectiveness of sulfanilamide due to a competitive mechanism.

• In the aqueous prescription containing sodium citrate, calcium bromide syrup, incompatibility may occur due to: Physicochemical incompatibility causing precipitation.

• In the aqueous prescription containing sodium citrate, calcium bromide syrup, one of the following incompatibilities may occur: One chemical incompatibility and one pharmacological incompatibility.

• In the prescription containing ferrous sulfate, quinine syrup, which of the following incompatibilities may occur: Physicochemical incompatibility causing precipitation.

• In the formula: Sodium phenobarbital 10 centigrams, Ammonium chloride 5 g, orange syrup 30 g, purified water 150 ml. Incompatibility occurs: No incompatibility occurs.

• The approach to choose to resolve incompatibility in the following formula: Change the solvent.

• Incompatibility causing precipitation in the formula: Ephedrine.HCl 1 g, Potassium iodide 15 g, Lobelin alcohol 20 g, Ammonium aniseed alcohol 2 g can be overcome by replacing: Ammonium aniseed alcohol.

• Which incompatibility occurs in the following formula: Calcium bromide 5 g, Almond oil emulsion 30 g: Physical incompatibility causing emulsion layer destruction.

• For the formula: Belladonna extract 10 ctg, Papaverine 30 ctg, Activated charcoal 0.5 g: Physical incompatibility causing adsorption.

• For the formula: Methyl salicylate 3 g, 10% camphor oil 50 ml, 70o alcohol 50 ml. Incompatibility in the formula can be overcome by: Choosing one of the two solvents.

• Of the following substances, which one may be incompatible with menthol to form a eutectic mixture: Phenol.

Note:

• Incompatibility is an undesirable phenomenon occurring between components in a drug formula, which may alter the properties and effectiveness of the drug.

• There are many types of incompatibilities, including chemical incompatibility, physical incompatibility, and pharmacological incompatibility.

Conclusion:

This article has provided some basic knowledge on Pharmaceutical Preparations II, including concepts, methods, excipients, dosage forms, incompatibilities. Hopefully, the article will help you better understand this field.