Osmotic Drug Delivery System

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Osmotic tablet:

Osmotic tablet AND RECENT ADVANCEMENT IN IT Presented by: Nidhi Lathia, Atmiya Institute of Pharmacy, Rajkot

Introduction:

Introduction Osmosis can be defined as the net movement of water across a selectively permeable membrane driven by a difference in osmotic pressure across the membrane. It is driven by a difference in solute concentrations across the membrane that allows passage of water, but rejects most solute molecules or ions. Osmotic pressure is the pressure which, if applied to the more concentrated solution, would prevent transport of water across the semipermeable membrane. 2 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction The first osmotic effect was reported by Abbe Nollet in 1748. Later in 1877, Pfeffer performed an experiment using semi-permeable membrane to separate sugar solution from pure water. He showed that the osmotic pressure of the sugar solution is directly proportional to the solution concentration and the absolute temperature. In 1886, Vant Hoff identified an underlying proportionality between osmotic pressure, concentration and temperature. He revealed that osmotic pressure is proportional to concentration and temperature and the relationship can be described by following equation. 3 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction Π = p c RT Where, p = Osmotic pressure Π = osmotic coefficient c = molar concentration R = gas constant T = Absolute temperature 4 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction Solutions of different concentrations having the same solute and solvent system exhibit an osmotic pressure proportional to their concentrations. Thus a constant osmotic pressure, and thereby a constant influx of water can be achieved by an osmotic delivery system that results in a constant zero order release rate of drug. Osmotic pressure is used as driving force for these systems to release the drug in controlled manner. These systems can be used for both route of administration i.e. oral and parenterals . Oral osmotic systems are known as gastro-intestinal therapeutic systems (GITS). Parenteral osmotic drug delivery includes implantable pumps. 5 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction About 75 years after discovery of osmosis principle Rose and Nelson, the Australian scientists, initiated the osmotic drug delivery system. They developed an implantable pump, which consisted of three chambers: a drug chamber, a salt chamber contains excess solid salt, and a water chamber. The design and mechanism of this pump is comparable to modern push-pull osmotic pump. The major disadvantage of this pump was the water chamber , which must be charged before use of the pump. 6 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction 7 Osmotic tablet and recent advancement in it- Nidhi Lathia Modified version of Rose Nelson Pump Higuchi Leeper Pump Higuchi-Leeper pump

Introduction:

Introduction It has no water chamber , and the device is activated by water imbibed from the surrounding environment. The pump is activated when it is swallowed or implanted in the body. This pump consists of a rigid housing, and the semipermeable membrane is supported on a perforated frame. It has a salt chamber containing a fluid solution with excess solid salt. Recent modification in Higuchi-Leeper pump accommodated pulsatile drug delivery. Further simplified variant of Rose-Nelson pump was developed by Higuchi and Theeuwes. 8 Osmotic tablet and recent advancement in it- Nidhi Lathia

Introduction:

Introduction This pump comprises a rigid, rate controlling outer semipermeable membrane surrounding a solid layer of salt coated on the inside by an elastic diaphragm and on the outside by the membrane. In use, water is osmotically drawn by the salt chamber, forcing drug from the drug chamber. 9 Osmotic tablet and recent advancement in it- Nidhi Lathia

Advantages:

Advantages The delivery rate of zero-order is achievable with osmotic systems. Delivery may be delayed or pulsed, if desired. Higher release rates are possible with osmotic systems compared with conventional diffusion-controlled drug delivery systems . The release rate of osmotic systems is highly predictable and can be programmed by modulating the release control parameters. For oral osmotic systems, drug release is independent of gastric pH and hydrodynamic conditions. The release from osmotic systems is minimally affected by the presence of food in gastrointestinal tract. A high degree of in vivo- in vitro correlation (IVIVC) is obtained in osmotic systems. 10 Osmotic tablet and recent advancement in it- Nidhi Lathia

disadvantages:

disadvantages 11 Osmotic tablet and recent advancement in it- Nidhi Lathia Osmotic system

Classification:

Classification 12 Osmotic tablet and recent advancement in it- Nidhi Lathia Oral osmotic tablet

Criteria for selection of a drug :

Criteria for selection of a drug Short biological Half-life (2- 6 hrs) High potency Required for prolonged treatment (e.g: Nifedipine, Glipizide, Verapamil and Chlorpromazine hydrochloride). 13 Osmotic tablet and recent advancement in it- Nidhi Lathia

Basic components:

Basic components Drug Osmotic agent Semipermeable membrane Coating material Hyrophilic and hydrophobic polymers Wicking agents Solubilizing agents Surfactant Plasticizers Flux regulators Pore forming agents 14 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic agents:

Osmotic agents Polymeric osmogents are mainly used in the fabrication of osmotically controlled drug delivery systems and other modified devices for controlled release of relatively insoluble drugs. Osmotic pressures for concentrated solution of soluble solutes commonly used in controlled release formulations are extremely high, ranging from 30 atm for sodium phosphate up to 500 atm for a lactose-fructose mixture. These osmotic pressures can produce high water flows across semipermeable membranes . 15 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic agents:

Osmotic agents The osmotic water flow across a membrane is given by the equation, dv/dt = A θ∆π l Where, dv/dt, is the rate of water flow across the membrane of area A, thickness l, permeability θ in cm 3 , and ∆π . 16 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic pressure of saturated solutions of commonly used pharmaceutical solutes:

Osmotic pressure of saturated solutions of commonly used pharmaceutical solutes 17 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic pressure of saturated solutions of commonly used pharmaceutical solutes:

Osmotic pressure of saturated solutions of commonly used pharmaceutical solutes 18 Osmotic tablet and recent advancement in it- Nidhi Lathia

Semipermeable membrane:

Semipermeable membrane The membrane must possess certain performance criteria such as: Sufficient wet strength and water permeability Should be biocompatible Rigid and non-swelling Should be sufficient thick to withstand the pressure within the device. Any polymer that is permeable to water but impermeable to solute can be used as a coating material in osmotic devices. e.g. Cellulose esters like cellulose acetate, cellulose acetate butyrate, cellulose triacetate and ethyl cellulose and Eudragits. 19 Osmotic tablet and recent advancement in it- Nidhi Lathia

Coating material:

Coating material Different types and amount of plasticizers used in coating membrane also have a significant importance in the formulation of osmotic systems. They can change visco-elastic behavior of polymers and these changes may affect the permeability of the polymeric films. Some of the plasticizers used are as below: Polyethylene glycols Ethylene glycol monoacetate; and diacetate- for low permeability Triethyl citrate Diethyl tartarate or Diacetin- for more permeable films 20 Osmotic tablet and recent advancement in it- Nidhi Lathia

HYDROPHILIC AND HYDROPHOBIC POLYMERS:

HYDROPHILIC AND HYDROPHOBIC POLYMERS These polymers are used in the formulation development of osmotic systems containing matrix core. The selection of polymer is based on the solubility of drug as well as the amount and rate of drug to be released from the pump. The highly water soluble compounds can be co-entrapped in hydrophobic matrices and moderately water soluble compounds can be co-entrapped in hydrophilic matrices to obtain more controlled release. Examples of hydrophilic polymers are hydroxy ethyl cellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, etc. Examples of hydrophobic polymers are ethyl cellulose, wax materials, etc. 21 Osmotic tablet and recent advancement in it- Nidhi Lathia

WICKING AGENTS:

WICKING AGENTS It is defined as a material with the ability to draw water into the porous network of a delivery device. The function of the wicking agent is to draw water to surfaces inside the core of the tablet, thereby creating channels or a network of increased surface area. Examples are colloidon silicon dioxide, kaolin, titanium dioxide, alumina, niacinamide , sodium lauryl sulphate (SLS), low molecular weight polyvinyl pyrrolidone (PVP), bentonite , magnesium aluminium silicate, polyester and polyethylene, etc. 22 Osmotic tablet and recent advancement in it- Nidhi Lathia

SOLUBILIZING AGENTS:

SOLUBILIZING AGENTS Non swellable solubilizing agents are classified into three groups Agents that inhibits crystal formation of the drugs or otherwise act by complexation of drug (e.g., PVP, PEG, and Cyclodextrine ) A high HLB micelle forming surfactant, particularly anionic surfactants (e.g., Tween 20, 60, 80, poly oxy ethylene or polyethylene containing surfactants and other long chain anionic surfactants such as SLS). Citrate esters and their combinations with anionic surfactants (e.g., alkyl esters particularly triethyl citrate). 23 Osmotic tablet and recent advancement in it- Nidhi Lathia

SURFACTANT:

SURFACTANT They are added to wall forming agents. They act by regulating the surface energy of materials to improve their blending in to the composite and maintain their integrity in the environment of use during the drug release period. Examples: polyoxyethylenated glyceryl recinoleate, polyoxyethylenated castor oil having ethylene oxide, glyceryl laurates, etc. 24 Osmotic tablet and recent advancement in it- Nidhi Lathia

PLASTICIZERS:

PLASTICIZERS Permeability of membranes can be increased by adding plasticizer, which increases the water diffusion coefficient. Examples: dialkyl phthalates, trioctyl phosphates, alkyl adipates, triethyl citrate and other citrates, propionates, glycolates, glycerolates, myristates, benzoates, sulphonamides and halogenated phenyls. 25 Osmotic tablet and recent advancement in it- Nidhi Lathia

FLUX REGULATORS:

FLUX REGULATORS Flux regulating agents or flux enhancing agent or flux decreasing agent are added to the wall forming material; it assist in regulating the fluid permeability through membrane. Polyhydric alcohols such as poly alkylene glycols and low molecular weight glycols such as poly propylene, poly butylene and poly amylene,etc. can be added as flux regulators. 26 Osmotic tablet and recent advancement in it- Nidhi Lathia

PORE FORMING AGENT:

PORE FORMING AGENT These agents are particularly used in the pumps developed for poorly water soluble drug and in the development of controlled porosity or multiparticulate osmotic pumps. The pore formers can be inorganic or organic and solid or liquid in nature. Like, Alkaline metal salts such as sodium chloride, sodium bromide, potassium chloride, etc. Alkaline earth metals such as calcium chloride and calcium nitrate Carbohydrates such as glucose, fructose, mannose, etc. 27 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic pump & its component:

Osmotic pump & its component 28 Osmotic tablet and recent advancement in it- Nidhi Lathia

Recently in use osmotic pump :

Recently in use osmotic pump 29 Osmotic tablet and recent advancement in it- Nidhi Lathia Drug solution leaving via delivery portal Removable cap Flow moderator Semipermeable membrane Osmotic agent Flexible impermeable reservoir wall Reservoir

Elementry osmotic pump (EOP):

Elementry osmotic pump (EOP) EOP is the most basic device made up of a compressed tablet. The EOP consists of an osmotic core with the drug, surrounded by a semipermeable membrane . The semipermeable membrane is provided with a hole for the controlled delivery of the saturated solution of the drug formed as a result of imbibition of water whose rate is determined by the fluid permeability of the membrane and the osmotic pressure of the compressed tablet when the dosage form is placed in the aqueous environment. Application : Moderately soluble drug. Normally EOP deliver 60 – 80 % of its content at constant rate. It has short lag time of 30 – 60 minute. 30 Osmotic tablet and recent advancement in it- Nidhi Lathia

Slide 31:

Osmotic tablet and recent advancement in it- Nidhi Lathia 31 Fig. : EOP Limitations: SPM should be 200-300 μ m thick to withstand pressure Thick coatings lowers the water permeation rate Applicable mostly for water soluble drugs

Controlled porosity osmotic pump:

Controlled porosity osmotic pump 32 Osmotic tablet and recent advancement in it- Nidhi Lathia It is laser or micro driven orifice. When Controlled Porosity Osmotic pump is placed in aqueous environment the water soluble component of coating dissolves and forms micropores in membrane and water diffuses inside the core through microporous membrane, setting up an osmotic gradiant and thereby controlling the release of drug.

Controlled porosity osmotic pump:

Controlled porosity osmotic pump A controlled porosity wall can be described as having a sponge .like appearance. Generally, materials producing from 5 to 95% pores with a pore size from 10A - 100µm can be used . The resulting membrane is substantially permeable to both water and dissolved solute. Water-soluble additives used for this purpose are dimethyl sulfone, saccharides, amino acids, sorbotil, etc. Core: API ± osmogents Coat: Semi permeable membrane with water soluble additives 33 Osmotic tablet and recent advancement in it- Nidhi Lathia

Osmotic bursting osmotic pump:

Osmotic bursting osmotic pump Core: API ± osmogents 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. 34 Osmotic tablet and recent advancement in it- Nidhi Lathia

Push-pull osmotic pump (PPOP):

Push-pull osmotic pump (PPOP) Core Tablet: Layer 1:  API ± osmogents Layer 2: Polymeric osmotic agents Coat: Semi permeable membrane with delivery orifice. It is a bilayer tablet coated with semi permeable membrane. The PPOP system consists of two compartments separated usually by an elastic diaphragm. The upper compartment contains the drug and is connected to the outside environment via a small delivery orifice. It is used for delivery of APIs having extremes of water solubility . Modifications can be done: - delayed push-pull - multi-layer push-pull - push-stick system 35 Osmotic tablet and recent advancement in it- Nidhi Lathia

Push-pull osmotic pump (PPOP):

Push-pull osmotic pump (PPOP) 36 Osmotic tablet and recent advancement in it- Nidhi Lathia

Push-pull osmotic pump (PPOP):

Push-pull osmotic pump (PPOP) 37 Osmotic tablet and recent advancement in it- Nidhi Lathia

Sandwiched Osmotic tablets (SOTS):

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 38 Osmotic tablet and recent advancement in it- Nidhi Lathia

Sandwiched Osmotic tablets (SOTS):

Sandwiched Osmotic tablets (SOTS) 39 Osmotic tablet and recent advancement in it- Nidhi Lathia

Duros osmotic pump:

Duros osmotic pump 40 Osmotic tablet and recent advancement in it- Nidhi Lathia

Duros osmotic pump:

Duros osmotic pump 41 Osmotic tablet and recent advancement in it- Nidhi Lathia Design : Implantable drug-dispensing osmotic pump, shaped as a small rod with titanium housing. Mechanism : Through osmosis, water from the body is slowly drawn through the semi-permeable membrane into the pump by osmotic agent residing in the engine compartment, which expands the osmotic agent and displaces a piston to dispense small amounts of drug formulation from the drug reservoir through the orifice. Application: Systemic or site-specific administration of a drug

Duros osmotic pump:

Duros osmotic pump 42 Osmotic tablet and recent advancement in it- Nidhi Lathia

duros osmotic pump:

Osmotic tablet and recent advancement in it- Nidhi Lathia 43 duros osmotic pump

Duros osmotic pump:

Duros osmotic pump 44 Osmotic tablet and recent advancement in it- Nidhi Lathia

Duros osmotic pump:

Duros osmotic pump 45 Osmotic tablet and recent advancement in it- Nidhi Lathia

Duros osmotic pump:

Duros osmotic pump 46 Osmotic tablet and recent advancement in it- Nidhi Lathia

alzet osmotic pump:

alzet osmotic pump 47 Osmotic tablet and recent advancement in it- Nidhi Lathia

alzet osmotic pump:

alzet osmotic pump 48 Osmotic tablet and recent advancement in it- Nidhi Lathia Design: Empty reservoir within the core of the pump is filled with the drug or hormone solution to be delivered and is surrounded by salt chamber with impermeable layer between them. 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.

alzet osmotic pump:

alzet osmotic pump 49 Osmotic tablet and recent advancement in it- Nidhi Lathia

alzet osmotic pump:

alzet osmotic pump 50 Osmotic tablet and recent advancement in it- Nidhi Lathia

Marketed formulations:

Marketed formulations 51 Osmotic tablet and recent advancement in it- Nidhi Lathia

Marketed formulations:

Marketed formulations 52 Osmotic tablet and recent advancement in it- Nidhi Lathia

Question bank:

Question bank What is ODDS? Why it is required? Enumerate recent advance in controlled osmotic drug delivery system with their approaches. What are ideal properties of semi permeable membrane? Suggest few materials for this. Wright note on evaluation of osmotic pump. Write a note on principle of osmotic drug delivery system. Give advantage and disadvantage of osmotic drug delivery system. Give name of osmotic pumps. Give detail on elementary osmotic pump. 53 Osmotic tablet and recent advancement in it- Nidhi Lathia

References:

References 54 Osmotic tablet and recent advancement in it- Nidhi Lathia Gupta Roop, Gupta Rakesh, Basniwal Pawan k, Rathore Garvendras, Osmotically controlled oral drug delivery systems: a review, int. J. Ph. Sci., 2009, 1(2), 269-275. Gohel M.C Parikh .R.K , Shah. N.Y Osmotic drug delivery- an update, pharmainfo.net, 2009, 7(2). Lachman L., Liberman H. A., Kanig J. L., The theory and practise of industrial pharmacy. 2 nd Edition 1991, Varghese publishing house, Pg. 455. Aulton M. E., pharmaceutics the science of dosage form design. 2 nd Edition 2002, Churchill livingstone, Pg. 38, 39, 74, 304, 417. Ajay Babu, M. Prasada Rao, Vijaya Ratna J, Controlled-porosity osmotic pump tablets-an overview, jprhc. Shailesh Sharma. Osmotic controlled drug delivery. Pharmainfo.net. 2008; 6(3).

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Osmotic tablet and recent advancement in it- Nidhi Lathia 55

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Osmotic tablet and recent advancement in it- Nidhi Lathia 56 THANK YOU

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