Introduction of osmotic drug delivery system. Mechanism of osmosis. Basic Components of Osmotic drug delivery System. Classification of Osmotic Drug Delivery System. Advantage & Disadvantage of Osmotic drug delivery system. Newer technology in Osmotic drug delivery system. Evaluation parameters of osmotic drug delivery system. Marketed Formulations of Osmotic drug delivery system. Case Study about osmotic drug delivery system.

1. Osmotic drug delivery
system
Presented by :-
Pratik Pandit Shinde
M.Pharm
(Pharmaceutics)

2. Contents:
Introduction
 Mechanism of osmosis
 Basic Components of Osmotic Pump System
 Classification of Osmotic Drug Delivery System
 Advantage & Disadvantage of ODDS
 Newer technology in ODDS
 Evaluation parameters
 Marketed Formulations
 Case Study
 References

3. Introduction
Conventional oral drug dosage forms are known to provide a prompt release
of active ingredients, but one cannot control the release of the medication and
cannot maintain a therapeutic concentration at the desired site for a long time.
Various factors affect the rate and extent to which the drug reaches systemic
circulation after administration, including the excipients used,
physicochemical properties of the active ingredient, physiology and pH of the
gastrointestinal tract, gastric emptying rate and GI motility.

4. To overcome these limitations with conventional dosage forms, controlled-
release drug delivery systems, through which the drug is released in a predicted
and sustained manner, have been developed.
Among the various controlled-release systems, osmotic drug delivery systems
provide substantial advantages.
Osmotic pressure: The pressure exerted by the flow of water through a
semipermeable membrane separating two solutions with different concentrations
of solute.

5. Plasma concentration profile: 1) For
conventional dosage form (- - -) and 2) For
controlled release dosage form (—).

6. .
Osmotic Drug Delivery System
Osmosis is defined as the movement of water from a region with a
higher concentration to a region with a lower concentration across a semi-
permeable membrane.
Osmotic delivery systems or osmotic pumps are mainly composed of a
core containing a drug and an osmogen

7. These are coated with a semi-permeable membrane containing one or
more ports for drug delivery, such that the drug is released over time in the
form of a solution or suspension.
The core consists of a drug formulation that contains an osmotic agent and
a water swellable polymer.
The rate at which the core absorbs water depends on the osmotic pressure.
Critical factors that influence the design of osmotically controlled drug
delivery systems, including the drug solubility, delivery orifices, osmotic
pressure, semi-permeable membrane, type and nature of the polymer,
membrane thickness, and type and amount of plasticizer
.

8.  Core contain water soluble osmotically active agent and blended with
water soluble or insoluble drug, additives and coating has been carried
out which functions as semi permeable membrane.
 Since barrier is only permeable to water, initial penetration of water
dissolves the critical part of the core, resulting in development of an
osmotic pressure difference across the membrane.
 The device delivers a saturated volume equal to the volume of water
uptake through the membrane. Initial lag time (per hour) during which
delivery rate increases to its maximum value, drug release is zero
order, until all solid material is dissolved.
Mechanism of osmotic DDS

9. Mechanism of osmotic DDS

10. Basic components of osmotic drug delivery system
Drug
Coating agent
Wicking agent
Osmotic agent
Semipermeable membrane
Pore forming agent
Plasticizers

11. Drug:
 Which have short biological half-life and which is used for prolonged
treatment are ideal candidate for osmotic systems.
 Various drug candidates such as Diltiazem HCl, Carbamazepine, Metoprolol,
Oxprenolol, Nifedipine, Glipizide etc. are formulated as osmotic delivery.
Coating agent:
Solvents suitable for making polymeric solution that is used for manufacturing
the wall of the osmotic device include inert inorganic and organic solvents that
do not adversely harm the core, wall and other materials.
The typical solvents include methylene chloride, acetone, methanol, ethanol,
isopropyl alcohol, butyl alcohol, ethyl acetate, cyclohexane, carbon
tetrachloride, water etc.

12. Wicking Agent
The function of the wicking agent is to carry water to surfaces inside the core
of the tablet there by creating channels or a network of increased surface area.
Wicking agents include colloidal silicon dioxide, kaolin, titanium dioxide,
alumina, niacinamide, sodium lauryl sulphate (SLS), low in weight poly (vinyl
pyrrolidone) PVP, m-pyrol, bentonite, magnesium aluminium silicate, polyester
and polyethylene
Osmotic agent
They are used to create osmotic pressure inside the system.
To enhance the release rate osmotic agent is added in the formulation.
E.g. Mannitol, Glycerol, lactulose, sorbitol, or polyethylene glycol.

13. Semipermeable membrane:-
 An important part of the osmotic drug delivery system is the
semipermeable membrane housing. Therefore, the polymeric membrane
selection is key to the osmotic delivery formulation.
 The membrane should possess certain characteristics, such as
impermeability to the passage of drug and other ingredients present in the
compartments.
 The membrane should be inert and maintain its dimensional integrity to
provide a constant osmotic driving force during drug delivery.
 e.g. Cellulose esters like cellulose acetate, cellulose acetate butyrate,
cellulose triacetate and ethyl cellulose and Eudragits

14. Pore forming agent
 A microporous membrane forms due to the presence of pore-forming agents.
Alkaline metal salts such as potassium chloride, sodium chloride, and others may
be used as pore-forming agents.
Plasticizers
They can change visco-elastic behavior of polymers and these changes may affect
the permeability of the polymeric films.
E.g. Polyethylene glycols, Ethylene glycol monoacetate, Diacetate- for low
permeability, Tri ethyl citrate etc.

15. .
Classification of osmotic DDS
Single chamber
Osmotic Pump
Multi Chamber
Osmotic Pump
Oral Osmotic
Capsule
Implantable
Osmotic System
Elementary
Osmotic Pump
Controlled
porosity
Osmotic Pump
Osmotic
busting
Osmotic Pump
Sandwich
Osmotic tablet
OROS-CT
Push pull
Osmotic Pump
L-OROS
Rose &
Nelson
Osmotic Pump
Alzet Osmotic
Pump
Higuchi Leeper
Pump
Oral osmotic system

16. A.) Single chamber osmotic pump:
1.) Elementary osmotic pump (EOP):
 which made osmotic delivery as a major method of achieving
controlled drug release.
 Composition-
osmotic core coated with a semipermeable membrane and a
small orifice is created in the membrane

17. . 2.)Controlled Porosity Osmotic Pump(CPOP):
 The delivery orifice is formed by incorporation of a leachable water-soluble
component in the coating material
 Drug release from the whole surface of device rather than from a single
hole which may reduce stomach irritation problem

18. .  The semi permeable coating membrane contains water-soluble pore
forming agents like NaCl, KCl and Urea.
 Such formed pores becomes permeable for both water and solutes.
 The release rate from these types of systems has been reported to be
dependent on:
the coating thickness (20-500 µm)
level of soluble components in the coating solubility of the
drug in the tablet core
osmotic pressure difference across the membrane (8-500 atm)
but independent of the pH and agitation of the release media.
 E.g. Chitosan-based controlled porosity osmotic pump (Citric Acid as pore
forming) for colon-specific delivery system: screening of formulation
variables and in vitro investigation

19. . 3.) Osmotic bursting osmotic pump:
 Core: API + osmogenes
 Coat: Semi permeable membrane without delivery
orifice.
 When placed in aqueous environment, water is
imbibed and hydraulic pressure is built up inside the
system, then wall ruptures and the contents are
released.
 It is used for pulsated release.

20. B.)Multichamber osmotic pump:
1.) Push Pull Osmotic System (PPOP):
 They contain two or three compartment separated by elastic diaphragm
 Upper compartment contain drug with or without osmogen (drug
compartment nearly 60-80 %) and lower compartment (Push
compartment) contain Osmogen at 20-40%.
 It is a bilayer tablet coated with semi permeable membrane.
 E.g. Procardia XL for Nifedipine
Mechanism of PPOP

21. . 2.) Sandwiched Osmotic tablets (SOTS)
 It is composed of polymeric push layer sandwiched between two drug layers
with two delivery orifices.
 When placed in the aqueous environment the middle push layer containing the
swelling agents, swells and the drug is released from the delivery orifices.
 Advantage: the drug is released from the two orifices situated on opposite sides
of the tablet

22. C.)Oral osmatic capsule:
1.)OROS-CT
 It is developed by Alza co-operation.
 It is used as a once or twice a day
formulation for targeted delivery of drugs
to the colon.
 It consist of an enteric coat, SPM & core.
 Core consist of two compartments-
one compartment consist of drug near to
orifice, Second compartment consist of
osmopolymer.
 The OROS-CT can be a single osmotic
agent or it can be comprise of as many as
five to six push pull osmotic unit filled in
a hard gelatin capsule.

23. 2.)L-OROS
 Liquid OROS controlled release systems are designed to continuous drugs as
liquid.
 A liquid formulation is used for delivering insoluble drugs and
macromolecules.
 It combines the benefits of extended-release with high bioavailability.
 These are two types :
1.)L-OROS HARD CAP 2.)L-OROS SOFT CAP

24. A.)Implantable osmotic
system:
1.)ALZET osmotic pump:
 Mechanism: Water enters into the
salt chamber through semipermeable
membrane and causes compression
of flexible reservoir and delivery of
drug solution
 Application: To deliver drugs,
hormones, and other test agents
continuously at controlled rates from
one day to six weeks.

25. .
2.)Rose and nelson osmotic pump:
Composition: This pump is composed of three chambers: drug chamber, salt
chamber, holding solid salt and water chamber.
Mechanism: A semipermeable membrane separates the salt from water
chamber. The movement of water from water chamber towards the salt
chamber is influenced by difference in osmotic pressure membrane.
Conceivably volume of salt chamber increase due to water flow which
descends the latex diaphragm the salt and drug chambers, eventually the drug
is pumped out of device.

26. .
3.) Higuchi Leeper pump:
Composition:-This pump is made by the Alza
corporation Higuchi Leeper pump has no water
chamber, this pump contains a rigid housing, and a
semipermeable membrane supported on a perforated
frame. A salt chamber containing a fluid solution with
an excess of solid salt is usually present in this type of
pump.
Mechanism: Higuchi Leeper pump has no water
chamber, and activation of the device occurs after
imbibition of water from the surrounding environment.
This variation allows the device to be prepared loaded
with drug and can be stored for long prior to use.
Application: - Higuchi-Leeper pump is widely
employed for veterinary use.(To deliver hormone)

27. .
 Advantages of
ODDS:
 High release rate
 Deliver zero order
 Highly predictable
 Independent of gastric pH
& hydrodynamic condition
 High degree of IVIVC
 Release of large amount of
water-soluble drug
 Disadvantage Of ODDS:
 Expensive
 Change of toxicity due to dumping
 Rapid development of tolerance
 Hypersensitivity reaction may occur
 Integrity and consistency are difficult
 Release of drug depends on:-
size of hole/aperture
surface area
Thickness And
Composition Of membrane

28. .
Newer technology in ODDS:-
Osmodex® Technology - The Osmodex® family of proprietary
technologies combines laser drilled tablet technology with variety of single
active and multiple active drug delivery devices. Osmodex systems simplify
dosing and aid in patient compliance. It includes –
 Osmodex® ID delivery for insoluble drugs:-This platform provides
flexible delivery options for insoluble drugs. It can accommodate first
order, zero order or delayed release options while assuring full release
over the targeted time frame. This technology has been used to solve
multiple challenging insoluble drug delivery problems (Example -
Osmotica Nifedipine Extended release Tablets).

29. .
 Osmodex® SD delivery for soluble drugs:-This platform technology can be
used to resolve delivery challenges of soluble low-bioavailability drugs or
drugs requiring targeted delivery.
 Osmodex® Double CR combination:-This dual controlled release platform
allows delivery of two drugs from a single osmotic tablet where each drug
release pattern can be independently tailored to the desired release profile.
 Osmodex® Triple combination tablet:-This delivery system incorporates
compressed drug layers around an osmotic core. This combination provides
the benefits of immediate release and controlled release delivery, along with
the unique benefits of an osmotic controlled release to achieve three different
release rates in the same tablet

30. . Evaluation Parameter:
 In vitro evaluation:-The in vitro release of drugs from oral osmotic systems
has been evaluated by the dissolution apparatus. The dissolution medium is
generally distilled water as well as simulated gastric fluid (for first 2-4 h) and
intestinal fluids (for subsequent hours) have been used. The standard
specifications, which are followed for the oral controlled drug delivery
systems are equivalently applicable for oral osmotic pumps
 Effect of pH:-These are done to see the effect of pH on developed
formulations, so in-vitro study is carried out in different medias.
 Effect of osmotic pressure:- Release mechanism study is carried out at
different osmotic pressure to see its effect on the formulation.
 Effect of osmotic agent
 Swelling properties
 Membrane stability, thickness &Orifice diameter and drug release

31. Marketed Formulation:
Brand Name DRUG USED
Alpress LP Prazosin For the treatment of hypertension
Cardura XL Doxazosin mesylate For the treatment of hypertension
Concerta Methphenidate HCL Attention deficit hyperactivity disorder
Covera-HS Verapamil Management of hypertension and angina pectoris
Ditropan XL Oxybutynin chloride Overactive bladder. Symptom of urge urinary incontinence, urgency and
frequency
DynaCirc CR Isradipine For the treatment of hypertension
Efidac 24 Chlorpheniramine Allergy symptom and nasal congestion
Glucotrol XL Glipizide For control of hyperglycaemia in patient with non insulin dependent
diabetes
Sudafed 24 Hour Pseudoephedrine Nasal decongestant
Procardia XL nifedipine For the treatment of angina &hypertension
Volmax Albuterol Bronchospasm in patient with reversible obstructive airway disease

32. .

33. .
Case study:
Objective: The aim was to develop
osmotic tablets of nateglinide by two
methods namely elementary osmotic
pump (EOP) and push-pull osmotic pump
(PPOP) method for controlled drug
release.
Methods: The tablets were prepared by
the wet granulation and were evaluated for
various physicochemical parameters, in-
vitro dissolution and in-vitro dissolution.
The optimized formulation obtained in
both methods was further characterized
for FTIR, stability studies and
pharmacokinetic studies

34. .
Results: In EOP method coated tablet F14(Nateglinide-60mg,fructose-
160mg,polyvinylpyrrolidoneK30-30mg,MCC-140mg,talc-4mg,Mg.sterate-
6mg=400mg) showing highest drug release of 98.82%. In PPOP formulation FF14(
was optimized with highest drug release of 99.97% and also its granules were having
better flow property. Both F14 and FF14 were further characterized for FTIR, which
showed no significant interaction and the accelerated studies indicated formulations
were stable for 3months. The in-vivo studies in rabbits revealed Cmax of the
optimized formulation (FF14) was 469.67±0.034 ng/ml, and the Cmax of the
marketed product was 401.27±0.08 ng/ml. The Tmax of the formulation and the pure
drug were 6.0±0.07 h and 1.5±0.04 h, respectively.
Conclusion: A better improvement in-vitro dissolution profile and bioavailability of
the osmotic tablet of nateglinide was observed using
PPOP method.

35. . Reference
 Shireen F, Ajitha M, Roshan S. Nateglinide Modified Release Dosage Form Using Elementary
Osmotic Pump and Push Pull Osmotic Pump: Formulation and In-vivo Evaluation. Journal of
Pharmaceutical Negative Results. 2022;13(4):214. DOI: 10.47750/pnr.2022.13.04.214.
 Gupta BP, Thakur N, Jain NP, Banweer J, Jain S. Osmotically Controlled Drug Delivery System
with Associated Drugs. Journal Applied Pharmaceutical Sci. 2010;13(3):571-588.
 Keraliya RA, Patel C, Patel P, Keraliya V, Soni TG, Patel RC, Patel MM. Osmotic Drug Delivery
System as a Part of Modified Release Dosage Form. Journal Pharmaceutical Sci. 2012;15(1):1-10.
 Ghosh T, Ghosh A. Drug Delivery Through Osmotic Systems - An Overview. Journal Applied
Pharmaceutical Sci. 2011;01(02):38-49.
 Syed SM, Farooqui Z, Mohammed M, Dureshahwar K, Farooqui M. Osmotic Drug Delivery
System: An Overview. International Journal Of Pharmaceutical research and Allied Sci.
2015;4(3):10-20.
 Dhage CM, Shinkar DM, Pathan VT, Jadhav AG. A Review on Osmotic Drug Delivery System.
International Journal Of Pharmaceutical Science review and research. 2020;62(1):160-167.
 https://www.mdpi.com/1424-8247/15/11/1430
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3407637/

36. .
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