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Solubilization
Solubilization of drugs - DDS II
| Question | Answer |
|---|---|
| Which reaction has a positive delta H, endothermic or exothermic? | Endothermic (absorb heat) |
| True of False: Solubility of a basic drug decreases with a decrease in pH. | False |
| What must happen to intermolecular attractions before new solute-solvent attractive forces can become effective? | They must be broken. |
| What is the value of R? | 1.987 cal / mol deg |
| What is the pH at which half of a drug is unionized called? | pKa |
| What is the concentration at which micelles are formed called? | Critical micelle concentration |
| What is one of the primary influences on the solubility of most drugs that contain ionizable groups? | pH |
| What is Critical Micelle Concentrations (CMC)? | The concentration at which micelles are formed. |
| Water ________________ (takes in / gives off) to break apart is hydrogen bonds. | takes in |
| True or False: Solubility of basic drugs show a U shape solubility curve. | False |
| Which is the strongest intermolecular force? | Ionic bonding |
| What technique is used to increase aqueous solubility of weak electrolytes and non-polar molecules. | Solubilization by cosolvency |
| True or False: Solubility of acidic drug decreases with a decrease of pH. | True |
| What types of acids and bases are not soluble in water? | Weak acids and bases with high molecular weights |
| True or False: Solids can be used as cosolvents. | True |
| Which reaction has a negative delta H, endothermic or exothermic? | Exothermic (gives off heat) |
| True or False: Cyclodextrins have a hydrophobic portion on the inside. | True |
| True or False: Cyclodextrins have a hydrophilic portion on the inside. | False |
| How many members does a beta cyclodextrin have? | Eight |
| Micelles are used to solubilize what kind of drugs? | Hydrophobic |
| Most substances are ____________ (endothermic / exothermic) in the process of dissolution. | Endothermic (absorb heat) |
| Name a substance that gives off heat (exothermic) in the process of dissolution. | Calcium hydroxide |
| True or False: A solute will not dissolve in a solvent if the solute-solvent forces of attraction are weaker than the individual solute and solvent intermolecular attractions. | True |
| True or False: A solute will dissolve in a solvent if the solute-solvent forces of attraction are weaker than the individual solute and solvent intermolecular attractions. | False |
| Name five ways to increase the solubility of drug substances. | Salt formation, Change in physical form, Cosolvancy, Use of surfactants, Complexation |
| Name four factors affection solubility. | Temperature, Ionization, pH, Particle Size |
| True or False: Solubility of amphoteric drugs show a U shape solubility curve. | True |
| True or False: Solubility of acidic drugs show a U shape solubility curve. | False |
| Solubility of acidic drugs ___________ (increases / decreases) with decreasing pH. | Decreases |
| Solubility of acidic drugs ___________ (increases / decreases) with increasing pH. | Increases |
| Solutes that are completely ionized include _____________. | Strong acids and bases, and inorganic and organic salts, which are soluble in water. |
| The process of dissolving a chemical in a solvent is called _________. | Solubilization |
| This type of bonding is electrostatic attraction between a cation/anion and a dipole. | Ionization |
| This type of bonding is electrostatic attraction between cations and anions. | Ionic bonding |
| True or False: A micronized drug will have an decrease in solubility over a drug that is not micronized. | False |
| True or False: A micronized drug will have an increase in solubility over a drug that is not micronized. | True |
| Ionization of a solute generally __________ (increase / decreases) solubility. | Increases |
| How many members does a gamma cyclodextrin have? | Nine |
| Name a process that enhances intrinsic solubility of chemicals. | Solubilization |
| List the following in order of strength from weakest to strongest: Hydrogen bonding, Van der Waals Attraction, Ionic Bonding, Ionization. | Van der Waals Attraction, Hydrogen Bonding, Ionization, Ionic Bonding |
| Most drugs are _______ electrolytes. | Weak (because most organic molecules are weak organic acids or bases) |
| How many members does a alpha cyclodextrin have? | Seven |
| How do you enhance the solubility of a weak electrolyte? | Convert it to a salt |
| Henderson Hasselbach Equation | pH = pKa + log ( [A-] / [HA] ) |
| Delta H > 0 means ____________ (endothermic / exothermic). | Endothermic (absorb heat) |
| True or False: A valium (Diazepam) injection (5mg/mL) can be mixed with other solutions or drugs in IV or infusion. | False |
| True or False: A solute will dissolve in a solvent if the solute-solvent forces of attraction are great enough to overcome the solute-solute and solvent-solvent forces of attraction. | True |
| Delta H < 0 means ____________ (endothermic / exothermic). | Exothermic (gives off heat) |
| Solubility of a basic drug __________ (increases / decreases) with increasing pH. | Decreases |
| Cyclic oligosaccharides which have a hydrophobic inner side and a hydrophilic outer side are called _____________. | Cyclodextrins |
| Amphiphiles that are characterized by two distinct regions are called _________. | Surfactants |
| Aggregations of surfactants are called _____________. | Micelles |
| Acidic drugs are __________ (more / less) soluble in acidic solutions than in alkaline solutions. | less |
| A weak base becomes _____________ (ionized / unionized) in a strong basic environment. | Unionized |
| True or False: Solids are never used as cosolvents. | False |
| A weak base becomes _____________ (ionized / unionized) in a neutral or acidic environment. | Ionized |
| A weak acid in basic conditions exists as ______. | Ions |
| A micronized drug will have a(n) _____________ (increase / decrease) in solubility over a drug that is not micronized. | Increase |
| A weak acid becomes _____________ (ionized / unionized) in a neutral or acidic environment. | Ionized |
| True or False: A solute will not dissolve in a solve if the solute-solvent forces of attraction are great enough to overcome the solute-solute and solvent-solvent forces of attraction. | False |
| A weak acid becomes _____________ (ionized / unionized) in a strong acidic environment. | Unionized |
| Since the degree and extent of precipitation depends on the ability of a formulation to resist pH change when diluted, a __________ must often be used. | Buffer |
| Solubility of a basic drug __________ (increases / decreases) with decreasing pH. | Increases |
| Acidic drugs are __________ (more / less) soluble in acidic solutions than in alkaline solutions. | Less |
| True or False: Solubility of acidic drug increases with the increase of pH. | True |
| True or False: Solubility of acidic drug decreases with the increase of pH. | False |
| This type of bonding occurs between electron deficient and electron excessive atoms (dipoles). | Hydrogen Bonding |
| True or False: Only liquids can be used as cosolvents. | False |
| This type of bonding occurs between nonpolar groups. | Van der Waals Attraction |
| True or False: Solubility of acidic drug increases with the increase of pH. | True |
| True of False: Solubility of a basic drug increase with a decrease in pH. | True |
| Name four type of intermolecular forces. | Van der Waals attraction, Hydrogen bonding, Ionic Bonding, and Ionization |
| Name three types of interaction in the solubilization process. | Solvent-solvent interaction, solute-solute interaction, solvent-solute interaction |
| List the following in order of strength from weakest to strongest: Hydrogen bonding, Ionic Bonding, Ionization, Van der Waals Attraction. | Van der Walls Attraction, Hydrogen bonding, Ionization, Ionic Bonding. |
| What type of solubilization is used to increase aqueous solubility of weak electrolytes and nonpolar molecules? | Cosolvency |
| True or False: Never mix Valium (Dizazepam) injection (5mg/mL) with other solution or drung in IV or infusion. | True |
| Micellar solubilization could also be know as solubilization by ____________. | Surfactants |
| Cyclodextrins increase solubilization of a drug by forming ____________. | Inclusion complexes |