You are in browse mode. You must login to use MEMORY

level: PREFORMULATION STUDIES

Questions and Answers List

level questions: PREFORMULATION STUDIES

Question	Answer
__ of particle size, crystalline structure, melting point, solubility etc. Drugs can be used as solid, liquid and gases	Physical description
1 Liquids are volatile, must be physically sealed from __ to prevent __. 2 Liquid drugs intended for oral administration cannot be generally formulated to tablet form except for __ which is __. stored in tightly sealed glass container.	1 atmosphere, evaporation Ex. Amyl nitrite, Propylhexedrine 2 Nitroglycerin, sublingual
indication of particle size and size range of the raw material along with the crystal structure.	Microscopic Examination
1 Solid powders must __ and not become entangled 2 __ and __ powders flow more easily than __ powders	1 flow freely 2 Spherical, oval, needle-shaped
1 Operation of implantable pumps delivering medications, as well as in aerosol dosage forms, nasal inhalants 2 In case of spills in accessible places, the time to __ of a substance can be calculated	1 Heat of Vaporization 2 evaporation
1 Determines the: purity of the substance, compatibility of various subs before inclusion in the dosage form 2 has sharp melting point 3 depressed melting point	1 Melting Point Depression 2 Pure substances 3 Impure substances
valuable for interpreting interactions between two or more components	Phase Rule
affects : physical–chemical properties of drug substances: - dissolution rate - bioavailability - content uniformity - stability - taste - texture - flow properties and sedimentation rate	Particle Size
1 substances can exist in more than one crystalline form Evaluation of: crystal structure (microscopy, IR spectroscopy, thermal analysis, x-ray diffraction) polymorphism & *solvate form 2 different physical-chemical properties (melting pt. & solubility)	1 Polymorphism 2 Polymorphic forms
Determined by equilibrium solubility method - excess amount of drug + solvent = shaken at constant temp. over a prolonged period of time until equilibrium is obtained	Solubility
drug formulated to liquid product: adjustment of pH of solvent where drug is dissolved to adjust solubility	Solubility & pH
1 Time for the drug to dissolve in the fluids at the absorption site (rate-limiting step in absorption). 2 increased by decreasing the particle size. 3 use a highly water soluble salt of the parent substance.	1 Dissolution 2 Dissolution rate of drugs 3 higher dissolution rate
1 early assessment of passage of drug molecules across biologic membranes 2 permits absorption of lipid soluble substance by passive diffusion	1 Membrane Permeability 2 The biologic membrane (lipid barrier)
1 measure of a molecule's lipophilic character 2 used in formulation development	1 Partition Coefficient 2 Octanol-Water partition coefficient
1 extent of ionization of drug	1 pKa / Dissociation Constants
Hygroscopic Deliquescent Efflorescent Pack in 'tight' containers	Hydrates and Solvates
1 Used 'salts' to improve aq. Solubility 2 Salicylic acid+ NaOH ? ? 3 HCl + Ephedrine? ? 4 H3PO4 + Codeine?	1 Organic Salt Considerations 2 Sodium Salicylate 3 Ephedrine HCl 4 Codeine phosphate
Prepared for improving solubility, stability, resistance to degradation, use as prodrugs	Organic Ester Consideration