For many disease states the ideal dosage regimen is that by which an acceptable therapeutic concentration of drug at the site (s) of action is attainted immediately and is then maintained constant for the desired duration of the treatment.1 Over the past 30 years as the expense and complication involved in marketing new drug entities have increased, with concomitant recognition of the therapeutic advantage of modified release per oral dosage forms, greater attention has been focused on development of sustained, controlled release and delayed release system.
There are several reasons for the attractiveness of this dosage form. It is generally recognized that for many disease states, a substantial number of therapeuticatty effective compounds already exist. The effectiveness of these drugs however is often limited by side effects or the necessity to administer the compound in a clinical setting.
The goal in designing delayed release sustained or controlled delivery system is to
ØDecreased in dosing frequency
ØReduced peak to trough ratio of drug in systemic circulation.
ØReduced rate of rise of drug concentration in blood.
ØSustained & Consistent blood level with in the therapeutic window.
ØCustomized delivery profiles
ØReduced side effects
ØImproved patient compliance
Modified release drug products have been successfully marketed for many years. These products include dosage forms for oral & transdermal administration, as well as injectable & implantable system. Some marketed modified release product are given below
Example of marketed modified release product 4
Cata Press TTS
Ortho - Mcneil
Trans Dermal Patch
Trans Dermal Patch
Trans Dermal Patch
Trans Dermal Patch
Angenia / Hypertension
Ovearian cancer and Kaposi’s sarcoma
Advance prostate cancer
There are also some patented technologies of modified release drug delivery system
3.Elan drug technology
4.Microchip technology for delivery of insulin
5.OROS Push pull technology
6.L – Oros technology
7.En Sotrol technology
8. DUROS Technology
Port stands for programmable oral release technologies that use a unique coated in capsulated system with opportunity to provide multiple program release of drug. Port technologies offer significant flexibility in obtaining unique and desirable release profile to maximize pharmacological and therapeutic effect. There are mainly two dosage forms for port technology.
The dosage form consist form of polymer core matrix coated with the semi permeable, rate-controlling polymer. Poorly soluble drugs can coated with port properties solubilization agent to insure uniform control release from the dosage from
Fig.1 Drug release mechanism from the PORT tablet
The dosage from consist of a hard gelatin capsule coated with the semi permeable, rate controlling polymer. Inside coated capsule is the osmotic energy source, which normally contains the therapeutic agents to be delivers. The capsule is sealed with the water in soluble lipid separators plug and immediate release dosage can be edit above the plug the to complete the dosing option
Fig.2 Drug release mechanism from the PORT capsule
Flamel micro pumps technologies a controlled release system which permits delayed and extended delivery, of small molecule drugs. T is suitable in particularly narrow window of absorption from the upper part of the small intestine.
Flamel micro pump technology consists of a multiple per capsule or tablet containing micro particles per capsule or tablet. The 200-500 mm diameter size microform in the stomach and pass into the small intestine, where each micro particle, operation delivery system release the drug by osmotic pump at a adjustable rate (micro pump 1st or delayed for micro pump 2nd) and over and extended period of transit of time.
Fig.3 Flamel micropump technology
The design of micro pump micro particle allows extended transit time enough plasma mean resident time extended up to 24hours, which is spatially suited drug known to be absorbed only in small intestine the micro particle design can be adopted to be each drug specifically modifying the coating thickness and composition include the expedients (encapsulation) reduce toxicity and or reduces C max or peak drug concentration in the plasma (an improve patients regimen)
Elan offers more than 30 years experience in product development, optimization and manufacture and has engaged in successful coloration with more than 30 of the world’s leading pharmaceutical companies.
ELAN is focus on providing superior technologies platforms that can offer innovative high value, quality technologies to address the drug delivery challenges of the pharmaceutical industry.
ELAN delivers extecive scientific expenditure to help save difficult drug delivery and life cycle management challenges
ELAN continues to solve problems with poor solubility which can be in corporate in to a Verity of dosage forms as well as customization release profile for oral dosage forms.
PRIALT® Ziconotide intrathecal infusion
Azactan® Aztreonam for injection, USP
MAXIpime® Cefepim hydrochloride for injection
Researchers are working hard to develop an implantable insulin pump that can major blood sugar levels and deliver the exact amount of insulin needed. This would make it possible to mimic the action of natural insulin delivery.
Scientists are making progress with an implantable capsule that continuously produces insulin and release it to the blood stream.
The capsules developers have also over come biocompatibility problems using microchip technologies they has succeeds in creating a capsule that won’t be a attacked an destroyers by bodies immune system.
Push pulls system compromise bilayer or trilayer tablet core consting of one push layer and 1 or more drug layer. The drug layer contains the poorly soluble drugs, Osmotic agents and suspending agent. The push layer contains among other things, osmotic agent water swellable polymers. Asemipermeable membrane surrounds the tablet core.
Product comerslize using the push pull system include Glucotrol Xl® and procardia XL both composed of a bilayer tablet core and Concerta® compose of a tilayer .
Fig.4 Bilayer and trilayer OROS Push pull technology
To over come the drug solubility issue, Alza developed the L – OROS system where a lipid soft gel product containing drug in a dissolved state is initially manufactured and than coated with a barrier membrane, than osmotic push layer and than a semi preamble membrane, drilled with an exit orifice.
Fig.5 L – OROStm technolgoy
Shire laboratory use an integrated approach to drug delivery focusing on identification and incorporation of the identified enhancer into controlled release technologies to create optimized dosage form. Solubility enhancement of an order of magnitute or more can be achieved.
Fig.6 EN SO TROL Technology
The Duros technology is the miniature drug dispensing system that opposite like a miniature syringe and reglious minute quantity of concentrated from in a continues and constistant from over months or year.
The system consists from a outer cylindrical titanium alloy reservoir. This reservoir high impact strength and protects the drug molecules from enzymes, body mostres, cellular components that might deactivate the drug prepare to deliver
Fig.7 Duros technology
Advanced application of DUROS technology
Ø Chronogesictm ( Sufentanil) pain therapy system
ØTargeted drug delivery with catheterized osmotic pump
ØSite-specific drug delivery using Duros with a precious miniature catheters
In recent years, considerable attention has been focused on the development of novel drug delivery system technology. The reason for third shift is relatively low development cost and time required for introducing a NDDS technology approximately doller 20-50 million and between 3- 4 years and these technology also reduces the side effect and easy etc patient compliance. In the form of NDDS technology, an existing drug molecule can get a new life. Thereby increasing its market value competitiveness and life.
Drug delivery, in general, will continue to se significant growth in the pharmaceutical industry. In corporation of drug delivery concepts such as bioavailability enhancement and controlled release into the development of NCEs is the next logical steps.
1.Aulton E. Micheal, Modified release per oral dosage forms, Pharmaceutics – The Science of Dosage form Design , Churchill LivingSton New York, Page no.575
2. Banker S. Gilbert , Rhodes T. Christopher , Mordern Pharmeceutics , Marcel Dekker , Inc., New York, Page no. 575
3.Lachman Leon ,Lieberman A. Herbert , Kanig L. Joseph , The Theory and practices of Industrial Pharmacy , Varghese publishing House , Bombay, ed 3rd 430-431
4.Bhatt, Padmanabh, Osmotic delivery system for poorly soluble drug, The Drug delivery companies Report Autumn/Winter 2004 ©PharmaVentures Ltd 2004
6.www. Flamel. technologies.com (info @flamel .com)
9. Bhatt, Padmanabh, Osmotic delivery system for poorly soluble drug, The Drug delivery companies
Lecturer, Deptt. of Pharmaceutical Technology,Noida Institute of engg. and technology, Greater Noida.
Lecturer,K.N. Modi Institute of Pharmaceutical Education and Research, Modinagar