Oral Drug Delivery System

References

• Oral Controlled Release Formulation design

Oral delivery

• Both conventional and new drug deliverysystem:

• More flexibility in dosage forms• No sterility• Minimized damage at administration site

METHODS USED TO ACHIEVE

CONTROLLED RELEASE OF

ORALLY ADMINISTERED

DRUGS:

Ref:Oral controlled release formulation design

Ref:Oral controlled release formulation design

Bioerodable and Combination of Diffusion and Dissolution Systems

• It is characterized by a homogeneousdispersion of drug in an erodible matrix

DRUG DELIVERY FROM COMBINATION OF

DIFFUSION AND DISSOLUTION SYSTEM

Insoluble membrane

Entry of dissolution fluid

Diffusion of dissolved drug

Pore created by dissolution

of soluble fraction membrane

FIRST OSMOTIC PUMP (THREE CHAMBER ROSE-NELSON OSMOTIC PUMP)

Drug Chamber

Elastic Diaphragm

Salt Chamber

Rigid Semi permeable membrane

Water Chamber

Delivery orifice

A. Elementary osmotic pump

16/60

Semi permeable membraneCore

Delivery Orifice

• Major method of achieving controlled drug release • The EOP was developed by Alza under the name OROS forcontrolled release oral drug delivery formulations

MECHANISM OF EOP

17/60

MECHANISM OF PPOP (push pull osmotic pressure)

20/60

Modification in elementary osmotic pumps

Delivery orifice

Drug chamberInner microporous

membrane

Outer semi permeable

membrane

COMPOSITE MEMBRANE COATING USED TO DELIVER MODERATELY SOLUBLE DRUGS

• Another type of L-OROS consists of a hard gelatin capsulecontaining a liquid drug layer, a barrier layer and a pushlayer surrounded by a semipermeable membrane. The L-OROS hardcap system was designed to accommodate moreviscous suspensions with higher drug loading than would bepossible using softcap design.

Rate controlling membrane

Push layer

Inner Capsule

Delivery orifice

Inner Compartment

Barrier layer

Marketed productsELEMENTARY OSMOTIC PUMP

BRAND NAME APIEfidac 24® ChlorpheniramineAcutrim ® Phenylpropanolamine

Sudafed 24®, Efidac 24® Pseudoephedrine

Volmax ® AlbuterolMinipress XL® Prazosin

PUSH-PULL OSMOTIC SYSTEMS

Ditropan XL ® Oxybutynin chlorideProcardia XL® Nifedipine

Glucotrol ® GlipizideCovera HS ® Verapamil HCl

DynaCirc CR® IsradipineInvega® Paliperidone

Alpress LP® Prazosin

Fig.no-1

Fig.no-4

1- GAS GENERATING SYSTEMS

30

Cont…

Fig.no-6

FDDS: A review

High density systems • Barium sulphate , zinc oxide, iron powder, and

titanium dioxide are examples for excipients used.

Fig.no-8