Term
| What are the Factors Affecting Drug Release |
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Definition
• Order of reaction
• Formulation factors
• Physicochemical parameters
• Physiological factors |
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Term
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Definition
When rate of release is independent of concentration and constant over time
C = -k0t + Co
T1/2 = ½(C0/k0) |
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Term
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Definition
When rate of drug release is directly proportional to concentration remaining with time. ln C = - kt + ln Co
T1/2 = 0.693/k |
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Term
| What are 2 types of release systems? |
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Definition
| Immediate release or sustained release |
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Term
| What are the formulation factors? |
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Definition
type of release system
Type of dosage form
– Solid or liquid
– Route of delivery |
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Term
| Define Immediate Release Systems |
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Definition
| • Dosage forms that are designed to disintegrate and release their medication with no special rate controlling feature |
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Term
| What time of release system is Instantly Disintegrating Tablets? HOw fast do they dissolve? |
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Definition
| Immediate Release Systems, 10 s to 1 m |
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Term
| Define Modified release dosage forms |
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Definition
| Include dosage forms having drug release feature based on time course and location. |
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Term
| Why were Modified release dosage forms created? |
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Definition
| Designed to achieve convenience and therapeutic objectives not offered by conventional or immediate release dosage forms. |
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Term
| Define and list type for Sustained Release Dosage Forms: |
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Definition
| Dosage forms that provide medication over an extended time, Modified release dosage form |
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Term
| Define and list type for Controlled release dosage forms |
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Definition
| – These products are designed to release their medication in a controlled manner, at a predetermined rate, duration and location to achieve and maintain optimum therapeutic blood level of the drug |
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Term
| ________ _________ dosage form allows at least a two-fold reduction in dosing frequency as compared to their conventional dosage forms |
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Definition
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Term
| Define and list type of form for Repeat action |
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Definition
– Contains multiple doses of medication within same dosage form
– Each dose is released at a fixed interval
– E.g. Two layered tablets are prepared with one layer of drug for immediate release with the second layer designed to release the drug later either as a second dose or in an extended release manner, Controlled release dosage forms |
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Term
| Define and describe Chrono-Controlled Release |
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Definition
– A chrono-controlled release reflects the circadian rhythm of the patient.
– The drug release directly corresponds to the need of the patient, so when the condition of the disease is at its worst, blood concentrations of the drug is at it's peak |
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Term
| Define Site- Specific and Targeted Release |
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Definition
| Drugs are released to localized regions or at a specific site |
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Term
| Define Bio-responsive release |
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Definition
| he delivery system release drug in response to a biological stimulus. For example, blood glucose levels trigger release of insulin from a drug delivery device. |
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Term
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Definition
| The delivery system releases drug at a variable rate to match with endogenous circadian rhythms or mimics biological rhythms. |
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Term
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Definition
| – “Pulsatile release system enables immediate drug release in pulses that are separated by a defined time delay. This type of profile is beneficial when the intensity of a disease varies in a circadian rhythm fashion” |
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Term
| Define Modulated/self-regulated release |
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Definition
| – This type of system delivers necessary amount of drug under the control of a patient |
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Term
| Describe and give an example of Delayed release dosage forms: |
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Definition
– Does not release drug immediately
– Maintain drug within dosage form for some time before releasing
– Time based or environmental effect like gastrointestinal pH
– Example: Enteric coated tablets |
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Term
| The design of rate-controlled dosage forms is ________upon the unique characteristics of individual drugs |
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Definition
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Term
| Important aspects of the drug include ... |
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Definition
| physical, chemical and biological properties |
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Term
| For a sustained release product to maintain a constant drug level in the body, the drug must be released from the dosage form at a rate that will replace the amount of drug_____ through _____and ________ |
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Definition
| lost,metabolism ,excretion |
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Term
| Principles that control Rate of Release |
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Definition
Diffusion-controlled release mechanism
Dissolution controlled
Osmosis controlled
Mechanical controlled
Bio-responsive controlled |
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Term
| In diffusion controlled delivery system, the drug diffuses through a ... |
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Definition
| polymeric membrane, polymeric or lipid matrix. |
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Term
| Diffusion controlled devices could be of two types: |
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Definition
| Matrix device or Reservoir devices: |
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Term
| Describe Reservoir devices |
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Definition
– Pharmacological agent (drug) forms a core surrounded by an inert diffusion barrier (membrane)
-Membrane could be non-porous or microporous |
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Term
| Describe Matrix devices (also known as monolithic devices): |
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Definition
| Drug is dispersed or dissolved in an inert polymer or lipid. |
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Term
| In Dissolution-controlled Release Mechanisms drug release is controlled by controlling the ... |
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Definition
| dissolution rate of a polymer. |
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Term
| Dissolution controlled devices could also be of two types: |
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Definition
– Dissolution-controlled reservoir devices
– Dissolution-controlled matrix devices |
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Term
| In Dissolution-Controlled Reservoir Devices drug is retained by a polymeric membrane and after certain period of time ... |
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Definition
| polymeric membrane dissolves and releases the drug. |
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Term
| In dissolution controlled reservoir devices, the drug release is controlled by the ______ and/or the ________ ________of the polymeric membrane surrounding the drug core. |
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Definition
| thickness, dissolution rate |
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Term
| In dissolution controlled reservoir devices once the coating polymer is dissolved, the drug undergoes ________ and _________ |
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Definition
| dissolution and absorption. |
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Term
| Drug cores can be coated with polymers of different coating _______, so that drug release can be delayed for certain periods, e.g. 2, 4, 6 and 8 hrs. |
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Definition
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Term
| Coated drug can be placed in ________ or compressed into _______ |
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Definition
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Term
| Drug release is controlled by dissolution of the ... |
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Definition
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Term
| As the size of the matrix decreases with the process of dissolution, the amount of drug release ... |
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Definition
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Term
| The decrease in drug release can be compensated by manipulating the ... |
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Definition
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Term
| The movement of water results in the _______ in pressure in the solution and the resulting osmotic pressure can be used to pump out a drug from the delivery system. |
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Definition
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Term
| The _________ and _________ parameters can be controlled in order to achieve zero order release. |
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Definition
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Term
| Since Osmosis Controlled Drug Release devices require osmotic pressure to be effective, the device operates essentially ________ of the environment |
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Definition
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Term
| In Bio-responsive Controlled Release delivery systems, drug release can be controlled by ... |
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Definition
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Term
| In Bio-responsive Controlled Release devices the drug release can be controlled by controlling the ... |
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Definition
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Term
| pH can affect the________ of a polymeric membrane and is often called what type of release system? |
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Definition
| swellability, swelling-controlled release systems |
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Term
| In swelling-controlled release systems are initially____, when placed in the body, will absorb water or will come in contact with a certain pH and swell. |
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Definition
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Term
| In swelling-controlled release systems swelling _______water content of the formulation as well as the polymeric ______ _________ |
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Definition
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