بسم الله الرحمن الرحيم : بسم الله الرحمن الرحيم (وعلّمكَ ما لَم تَكن تَعلم وكان فَضلُ الله عليكَ عَظيما)
DRUG DELIVERY SYSTEMS
Second course 2009-2010
Dr. Issra H. Al-Ani Slide 2: The science of Drug Delivery may be described as the application of chemical and biological principles to control “in vivo” temporal and spatial location of drug molecules for clinical benefit.
Major addresses of drug delivery are:
1- Maximization of drug effect.
2- Minimization of side effect. Slide 3: FUTURE of drug delivery is guiding sufficient numbers of molecules in sufficient time to their targets.
POLYMERS are the key for improving DDS. Slide 4: The introduction of the first successful drug delivery system was brought by tremendous interest in the usage of different pharmaceutical means to achieve this goal.
Several drug delivery product followed into the market place and many are now in different stages of product development. Slide 5: Over the past decades, significant advances have been made in drug delivery technology. This effort pioneered by many companies and faculties has been accelerated in recent years due to the substantial decline in the development of new drug entities.
Drug delivery brings both therapeutic and commercial values to health care.
Presenting “old” drugs in “new” forms. Slide 6: New ideas:
Longer dosage schedules.
Improved safety profiles.
New indications for existing drugs.
Area of Research and Development in DDS:
Site –specific drug delivery.
Polymers and implantable DDS.
Transdermal, intranasal, ocular & misc.
Regulatory consideration and global outlook. Slide 7: DRUG DELIVERY is the use of whatever means possible, be it chemical, physicochemical or mechanical to regulate drug s access rate to the body s central compartment, or in some cases directly to the involved tissues.
DRUG DELIVERY SYSTEMS : are means used for entry of drug into the systemic circulation of the body. Slide 8: Advantages of novel DDS:
Exclusive delivery to specific site, access into primarily inaccessible site.
Protection of body from unwanted deposition.
Controlled rate and modality of delivery to pharmacological receptors.
Reduction of amount of active ingredient and side effects. Controlled Drug Delivery Systems : Controlled Drug Delivery Systems Controlled drug delivery technology represents one of frontier areas of science. These DS offer numerous adv. Compared to conventional DF, which include, improved efficacy, reduced toxicity
and improved patient compliance
and convenience. Types of CDDS : Types of CDDS Modified Release DDS
A term describes dosage form having drug release features bases on time course and/or location which are designed to accomplish therapeutic or convenience objective not offered by conventional DF. Extended Release DDS : Extended Release DDS FDA defines an ER dosage forms as one that allows a reduction in dosing frequency to that presented by a conventional DF. Delayed Release DDS : Delayed Release DDS Are those that use repetitive, intermittant dosing or a drug from one or more immediate release unit incorporated into a single DF. The delay may be time-base or based on influence of environmental conditions as GIT pH. Repeated Action DDS : Repeated Action DDS Layer tablet composed of two or three compressed together. It May involve sustained release preparation with immediate release unit. Advantages of CDDS : Advantages of CDDS Patient compliance is improved.
Decrease frequency with which the drug is taken. (dose at night, psychiatric people)
Reduced severity and toxicity of side effects.
More constant blood level improves therapeutic action. Disadvantages of CDDS : Disadvantages of CDDS Cost
Uncontrolled poisioning if poor formulation result in fast and high drug release.
Not suitable for many drugs that are absorbed from particular reagion.
Irritation at site of application.