Nasal & pulmonary drug delevary system & its application
Published on: Mar 3, 2016
Transcripts - Nasal & pulmonary drug delevary system & its application
NASAL & PULMONARY DRUG
DELEVARY SYSTEM & ITS
Under guidance of Prof. Sateesha. S.B
It is also a type of muco-adhesive drug delivery system.
Drugs are administered through nasal cavity by different
dosage forms like solutions , emulsions , gels etc.
Cytochrome p-450 dependent oxygenase , lactate
dehydrogenase , oxydoreductase , acid
hydrolases, esterases, lactic dehydrogenases, malic
enzymes, lysosomal proteinases, steroid hydroxylases
adult nasal secretion pH: 5.5-6.5
Infants & children : 5-6.7.
It becomes alkaline in conditions such as acute
rhinitis, acute sinusitis.
Lysosome in the nasal secretion helps as antibacterial &
its activity is diminished in alkaline pH.
The nasal mucosa has been considered as a
potential administration route to achieve faster and
higher level of drug absorption. This is due to the
large surface area & porous endothelial
The avoidance of first-pass metabolism, and ready
accessibility. Route of administration is the poor
contact of the formulations with the nasal mucosa.
Researchers became interested in the nasal route
for the systemic delivery of medication due to high
degree of vascularization and permeability of the
Pathologic conditions such as cold or allergies may alter
significantly the nasal bioavailability.
Low bio-availability for proteins and peptides and polar
Once administered, rapid removal of the therapeutic agent
from the site of absorption is difficult.
The histological toxicity of absorption enhancers used in
nasal drug delivery system is not yet clearly established.
Relatively inconvenient to patients when compare to oral
drug delivery systems since there is a possibility of nasal
Rapid muco ciliary clearance will occurs.
Chances of immunologic reactions
ANATOMY & PHYSIOLOGY OF NOSE
The nose is an important part of the face; it gives the individual his
The nose is divided into 2 parts:
1- The external nose.
2- The internal nose (nasal cavities)
1-The external nose:
It is the prominent part of the face, pyramidal in shape .the apex is the tip
of the nose; the base is the attached area to the forehead. The external
nose projecting downwards and is perforated by two apertures called the
nostrils separated by the columella.
The lateral surfaces joined along the dorsum of the nose where it meets
The external nose has a skeleton made up of bony and cartilaginous parts
The bony part is the two nasal bones, the nasal processes of the frontal
and maxillary bones .
The cartilaginous part is made up of 2 pairs of lateral
cartilages (upper lateral cartilages and lower lateral cartilages
) these cartilages are connected by fibrous tissue. The lower
lateral cartilages help in shaping the nostrils.
The outer surface is covered by skin which is thin and mobile
above and thick andadherent to the subcutaneous structures
near the tip.
2.The internal nose (the nasal cavity )
The nasal cavity is divided by midline partition (the nasal
septum) into right and left chambers,. It extends from the
nostrils in front into the choanae behind (where it opens into the
The entrance to the nasal cavity is called the nasal vestibule
which ends at themucocutaneous junction, it is lined by skin and
contains skin appendages.
the vestibule is a common site of boil development because it is
hair bearing area
The rest of nasal cavity lined by respiratory mucosa ( pseudo-
stratified columnar ciliate epithelium ), and small area lined by
Each cavity has a roof ,floor, medial and lateral walls .The
floor is formed by the palatine process of the maxilla and the
horizontal process of palatine bone.
The roof is narrow and is formed (from behind forward) by the
body of the sphenoid,cribriform plate of the ethmoid and the
Clinical point(4): cribriform plate is a thin plate of bone and
easily to be fractured in head injury and may associated with
CSF leak through the nose.
The medial wall (the nasal septum) is an osteocartilaginous
partition covered by adherent mucoperichondrium and
mucoperiostium .The upper part is formed by the
perpendicular plate of the ethmoid bone ,the posterior part by
the vomer and theanterior portion is formed by septal
The lateral wall is the most complex, it contains 3 shelf –like
projections into the nasal cavity called the turbinates ( the
superior, middle and the inferior turbinates )
The groove below each turbinate is referred to as a
meatus.There are 3 meati calledthe superior ,middle and
the inferior meatus) into these meati the paranasal sinuses
open and join the nasal cavity.The area above the superior
turbinate is called the sphenoethmoial recess.
The inferior meatus contain the opening of
The middle meatus contains the ostia (openings) of the
frontal ,maxillary and the anterior ethmoid sinuses.
3 The superior meatus receives the opening of the
posterior ethmoid sinus.
The sphenoethmoidal recees receives the opening of
the sphenoid sinus.
Blood supply of the nasal cavity
It supplied by branches of internal and external carotid
i branches of the internal carotid artery that supply the
nose are the anterior and posterior ethmoidal arteries
While the external carotid artery supplies the nose through it`s
maxillary branch and small contribution of the facial artery.
The internal carotid artery and external carotid artery branches
anastomose freely in the nose ,the common site of anastmosis
is in the antero-inferior part of the nasal septum (little`s area)
,the arteries that share in this anastmosis are the
sphenopalatine artery ,greater palatine artery, superior labial
artery and branch from the anterior ethmoidal artery .
The venous drainage
The nose characterized by rich submucosal plexus of venous
sinusoids ,these drained by veins that accompany the arteries.
NERVE SUPPLY OF THE NASAL CAVITY
1- Olfactory nerves: they arise from a specialized
olfactory epithelium in the olfactory
mucosa .they ascend through the cribriform plate to
reach the olfactory bulb.
2- Nerves of ordinary sensation: They are from the
ophthalmic and maxillary
divisions of the trigeminal nerve.
3-vasomotor nerve supply (the autonomic nerve
A-Parasympathetic when it is simulated it causes
vasodilatation. And stimulate
B- Sympathetic nerves it causes vasoconstriction
when stimulated and inhibit
THE PHYSIOLOGY OF THE NOSE
The nose has several functions
1- Respiratory function
a- It provides an airway for respiration.
b- Filtration of the inspired air.
c- Humidification of the inspired air.
d- Adjusts the temperature of he inspired air.
2- Olfactory function.
3- Phonatory function. It provides the voice with a resonant quality.
Approach to patient with nasal disease start from
2-Examination of the nose by anterior rhinoscopy using nasal speculum and
posterior rhinoscopy by post nasal mirror,and by edoscopic examination which can
done under local anaesthesia by using either fibro-optic endoscope(flexible)or rigid
the nasal bones usually demostated by plain lateral radiograph.
Radiography of the paranasal sinuses; there are several standard views of the sinuses
1-Occipitomental mental view it the most commonly requested view to demonstrate
the maxillary ,frontal and sphenoid sinuses
2-other views are occipittofrontal view, the lateral view and submentovertical view
2-Computerizd axial tomography (ct scan )
Advantages it delineates fine bony outline and soft tissue and is the preferred imaging
technique for detailed anatomy especially in relation to the skull base and the orbit
Disadvantage Is the ionizing radiation .
3-Magnaic resonanane imaging (MRI)
It delineate soft tissue better than ct scan and can distinguish between retained
secretion and soft tissue .It is an important investigation where the disease extends
outside the nose and sinuses for example into the anterior cranial fossa .
MECHANISM OF DRUG ABSORPTION
The first step in the absorption of drug from the nasal cavity is passage
through the mucus . Small, unchanged particles easily pass through
this layer. However, large or charged particles may find it more difficult
Mucin, the principle protein in the mucus, has the potential to bind
to solutes, hindering diffusion.
Structural changes in the mucus layer are possible as a result of
environmental changes (i.e. pH, température, etc.)subsequent to a
drug’s passage through the mucus.
There are several mechanisms for absorption through the mucosa.These
include transcellular or simple diffusion across the membrane, paracellular
transport via movement between cell and transcytosis by vesicle carriers .
Drug absorption are potential metabolism before reaching the systemic
circulation and limited residence time in the cavity.
Following mechanisms have been proposed :
I. The first mechanism involves an aqueous route of transport which is
also known as the paracellular route. This route is slow and passive.
There is an inverse log-log correlation between intranasal absorption
and the molecular weight of water-soluble compounds. Poor
bioavailability was observed for drugs with a molecular weight greater
than 1000 Daltons .
II. The second mechanism involves transport through a lipoidal route that
is also known as the transcellular process and is responsible for the
transport of lipophilic drugs that show a rate dependency on their
lipophilicity. Drugs also cross cell membranes by an active transport
route via carrier-mediated means or transport through the openingof
FACTORS INFLUENCING NASAL DRUG
Factors Related to Drug
On increasing lipophilicity, the permeation of the
compound normally increases through nasal mucosa
because of high lipophilicity though it has some
hydrophilic character.eg: alprenolol and propranolol.
b) Chemical Form
Its an important factor for absorption.
Conversion of the drug into a salt or ester form can alter
its absorption. eg: In-situ nasal absorption of carboxylic
acid esters of L-Tyrosine was significantly greater than
that of L-Tyrosine.
Polymorphism is known to affect the dissolution rate and
solubility of drugs and as well as their absorption through
It is therefore advisable to study the polymorphic stability
and purity of drugs for nasal powders or suspensions .
d) Molecular Weight
In the case of lipophilic compounds, a direct relationship
exists between the Molecular Weight and drug permeation
where as water soluble compounds depict an inverse
The permeation of drugs less than 300Da is not
significantly influenced by the physicochemical properties of
the drug, which will mostly permeate through aqueous
channels of the membrane. By contrast, the rate of
permeation is highly sensitive to molecular size for
compounds with MW = >300 Da.
e) Partition Coefficient and pKa
As per the pH partition theory, unionized species are absorbed
better compared with ionized species and the same holds true
in the case of nasal absorption.
Quantitative relationship between the physicochemical
properties of drugs and their nasal absorption, the results
showed that a quantitative relationship existed between the
partition coefficient and the nasal absorption constant .
The nasal absorption of weak electrolytes such as salicylic acid
and amino-pyrine was found to be highly dependent on their
degree of ionization.
Although for amino-pyrine, the absorption rate increased with
the increase in pH and was found to fit well to the theoretical
Substantial deviations were observed with salicylic acid. The
authors concluded that perhaps a different transport pathway,
along with the lipoidal pathway, eg:salicylic Acid pathways.
f) Solubility & Dissolution Rate
Drug solubility and dissolution rates are important factors
in determining nasal absorption from powders and
The particles deposited in the nasal cavity need to be dissolved
prior to absorption. If a drug remains as particles or is cleared,
no absorption takes place.
B) Factors Related to Formulation
1) Physicochemical Properties of the Formulation
a) pH and Mucosal Irritancy
The pH of the formulation, as well as that of nasal surface, can affect
a drug’s permeation. To avoid nasal irritation, the pH of the nasal
formulation should be adjusted to 4.5–6.5 . In addition to avoiding
irritation, it results in obtaining efficient drug permeation and prevents
the growth of bacteria.
Because of the effect of osmolarity on the absorption isotonic
solutions are usually preferred for administration for shrinkage of the
nasal epithelial mucosa.
This results in increased permeation of the compound resulting from
A higher viscosity of the formulation increases contact time between
the drug and the nasal mucosa there by increasing the time for
At the same time, highly viscous formulations interfere with the normal
functions like ciliary beating or mucociliary clearance and thus alter
the permeability of drugs.
POLYMERS FOR NASAL DDS:
DOSAGE FORM USED FOR DEVELOPING THE
Most simple and convenient systems developed for nasal
The main disadvantage of this system is the lack of dose
precision and therefore nasal drops may not be suitable for
prescription products .
It has been reported that nasal drops deposit human serum
albumin in the nostrils more efficiently than nasal sprays
Both solution and suspension formulations can be formulated
into nasal sprays.
Due to the availability of metered dose pumps and actuators,
a nasal spray can deliver an exact dose from 25 to 200 L.
The particle size and morphology(for suspensions) of the
drug and viscosity of the formulation determine the choice of
pump and actuator assembly.
Solution and suspension sprays are preferred over powder
sprays because powder results in mucosal irritation .
Nasal gels are high-viscosity thickened solutions or
Until the recent development of precise dosing devices, there
was not much interest in this system.
The advantages of a nasal gel include the reduction of post-
nasal drip due to high viscosity, reduction of taste impact due
to reduced swallowing, reduction of anterior leakage of the
formulation, reduction of irritation by using soothing/emollient
Excipients and target delivery to mucosa for better absorption
This dosage form may be developed if solution and suspension
dosage forms cannot be developed e.g.,due to lack of drug stability.
The advantages to the nasal powder dosage forms are the absence
of preservative and superior stability of the formulation. However, the
suitability of the powder formulation is dependent on the solubility,
particle size, aerodynamic properties and nasal irritancy of the active
drug and/or excipients.
Local application of drug is another advantageof this system but
nasal mucosa irritancy and metered dose delivery are some of the
challenges for formulation
Generally, the absorption enhancers act via one of the following
• Inhibit enzyme activity;
• Reduce mucus viscosity or elasticity;
• Decrease muco-ciliary clearance;
• Open tight junctions;
• Solubilize or stabilize the drug.
Absorption enhancers are generally classified as physical and
chemical enhancers. Chemical enhancers act by destroying
EVALUATION OF NASAL FORMULATIONS:-
In vitro diffusion studies:
The nasal diffusion cell is fabricated in glass.
The water jacketed recipient chamber has total capacity of
60 ml & a flanged top of about 3mm. the lid has 3
openings, each for sampling, thermometer, and a donor
tube has internal diameter of 1.13 cm.
The nasal mucosa of sheep was separated from sub layer
bony tissues & stoned in distilled water containing few
drops at gentamycin injection. After the complete removal
of blood from mucosal surface ,is attached to donor
The donor tube is placed such a way that it just touches
the diffusion medium in recipient chamber at
predetermined intervals, samples(0.5ml) from recipient
withdraw & transferred to amber colored ampoules .
The samples withdrawn is suitably replaced.
The samples are estimated for drug content by suitable
analytical technique, throughout the experiment temp is
maintained at 37˚c.
(B) In vivo nasal absorption studies:-
animal models for nasal absorption studies :
these models are 2 types.
a. Whole animal or in vivo model.
b. Isolated organ perfusion or ex vivo model.
(a) in vivo model:
1)e.g. Rat model:-
The rat is anesthetized by intra-peritoneal injection of sodium
pentobarbital. An incision is made in the neck & trachea is
cannulated with a polyethylene tube.
Another tube is inserted for through the oesophagus towards
the posterior region of the nasal cavity.
The passage of the naso palatine track is sealed so that the
the drug solution is not drained from nasal cavity through the
The drug solution is delivered to the nasal cavity through the
nostril or through the cannulating tubing.
The blood samples are collected from the only femoral vein.
As all the probable outlets are blocked, the drug can be only
absorbed and transported into the systemic circulation by
penetration or diffusion.
2) e.g.: rabbit model.
3)e.g.: dog model.
4)e.g.: monkey model.
Ex vivo nasal perfusion models:-
Surgical preparation is same that of in vivo rat model
During perfusion studies a funnel is placed between the
nose & reservoir to minimize the loss of drug solution.
The drug solution is placed in reservoir maintained at 37c
& is circulated through the nasal cavity of the rat with a
peristaltic pump the perfusion solution passes out from
nostrils &runs again into the reservoir, stirred continuously.
Amount of drug is absorbed is estimated by measuring the
residual drug concentration in the per fusing solution. the
drug activity due to stability problem may lost during the
This is especially for peptides & protein drugs that may
undergo proteolysis & aggregation.
Delivery of non-peptide pharmaceuticals
Delivery of diagnostic drugs
Delivery of peptide-based pharmaceuticals
1. Delivery of non-peptide pharmaceuticals
Drugs with extensive pre-systemic metabolism, such as
- sodium chromoglyate
can be rapidly absorbed through the nasal mucosa with a
systemic bioavailability of approximately 100%
2. Delivery of peptide-based pharmaceuticals
Peptides & proteins have a generally low oral bioavailability
because of their physico-chemical instability and susceptibility
to hepato-gastrointestinal first-pass elimination.
Eg. Insulin, Calcitonin, Pituitary hormones etc.
Nasal route is proving to be the best route for such
3. Delivery of diagnostic drugs
Diagnostic agents such as
Phenolsulfonphthalein – kidney function
Secretin – pancreatic disorders
Pentagastrin – secretory function of gastric acid
are administered through the nasal route.
1. CONTROLLED DRUG DELIVERY CONCEPTS
AND ADVANCES BY-S.P.VYAS & R.P.KHAR
2. MODERN PHARMACEUTICS FOURTH EDITION
BY- BANKER & RHODES
3. ADVANCE IN CONTROLLED AND NOVEL
DRUG DELIVERY BY-N.K. JAIN
Pulmonary route was use to treatment of different respiratory
diseases from the last decade. The inhalation therapies
involved the use of leaves from plants, vapors from aromatic
plants like balsams, and myhrr.
In the 1920 s adrenaline can introduce as a nebulizer solution,
in 1925 nebulizer porcine insulin was use in investigational
studies in diabetes, and in 1945 pulmonary delivery of the
newly revealed penicillin was investigated.
steroids had been introduced in between 1950s for the
treatment of asthma and nebulizers were enjoy widely use. In
1956 the pressured metered dose inhaler (pMDI) was placed.
lung associated bigger protein molecules may degrade into the
gastrointestinal situation and are excreted through the first
pass metabolism into the liver which can be transferred
through the pulmonary route if deposited in the respiratory
passage of the lungs .
FIG 1: DIFFERENT REGIONS OF THE HUMAN
ANATOMY AND PHYSIOLOGY OF
1) Lung regions:-
The respiratory tract starts at the nose and terminates deep
in the lung at an alveolar sac. There are a number of
schemes for categorizing the various regions of the
2) Nasopharyngeal region:-
This is also referred to as the “upper airways”, which
involves the respiratory airways from the nose down to the
3) Tracheo-bronchial region:-
This is also referred to as the “central” or “conducting
airways”, which starts at the larynx and extends via the
trachea, bronchi, and bronchioles and ends at the terminal
4) Alveolar region:-
This is also referred to as the “respiratory airways”,
“peripheral airways” or “pulmonary region”,Comprising the
respiratory bronchioles, alveolar ducts and alveoli.
The term “pulmonary” can be used to the alveolar region. The
use of “upper respiratory tract”
(i.e. NP plus trachea) and “lower respiratory tract”is also common
The lung contains more than 40 different cell types, of which
more than six line the airways.
The diversity of pulmonary epithelia can be illustrated by
examining its structure at three principal levels.
These are lined predominantly with ciliated and goblet cells.
Some serous cells, brush cells and Clara cells are also present
with few Kulchitsky cells.
These are primarily lined with ciliated cuboidal cells. The
frequency of goblet and serous cells decreases with progression
along the airways while thenumber of Clara
The alveolar region:-
This is devoid of mucus and has a much flatter epithelium,
which becomes the simple squamous type,0.1–0.5 μm thick.
Two principal epithelial cell types are present:
Type-I pneumocytes: Thin cells offering a very short airways-
blood path length for the diffusion of gasesand drug molecules.
Type-I pneumocytes occupy about 93% of the surface area of
the alveolar sacs.
• Type-II pneumocytes: Cuboidal cells that store and secrete
pulmonary surfactant. Alveolar macrophages account for ~ 3%
of cells in the alveolar region.
These phagocytic cells scavenge and transport particulate
matter to the lymph nodes and the mucociliary escalator.
In the trachea bronchial region, a high proportion of the
epithelial cells are ciliated such that there is a near complete
covering of the central airways by cilia.
Towards the periphery of the tracheobronchial region,the cilia
are less abundant and are absent in the alveolar region. The
ciliated cells each have about 200 cilia with numerous
interspersed microvilli, of about 1–2 μm in length. The cilia are
hair-like projections about 0.25 μm in diameter and 5 μm in
They are submersed in an epithelial lining fluid, secreted mainly
from the serous cells in the sub-mucosal glands.
The tips of the cilia project through the epithelial lining fluid into
a layer of mucus secreted from goblet cells.
The cilia beat in an planned fashion to propel mucus along the
airways to the throat.
MECHANISMS OF PARTICLE DEPOSITION IN THE
Effective resistance mechanisms may have involved may reduces
the burden of external particles enter the airways, and clearing
those it may achieve something in being stored.
Therapeutic aerosols are two-phase colloidal systems in that the
drug is contained in a dispersed phase they may have a solid,
liquid or combination of the two, based on themethod and
formulation of aerosol generation.
Evidently for effective therapy, the drug must have obtain able to
the lung in aerosol droplets or particles that deposit in the
specific lung region and insufficient quantity to be effective.
The respiratory resistance mechanisms of mucociliary clearance
and phagocytosis by macrophages may act upon insoluble
Aerosol particle dissolution they may slow and the drug may then
subsequently to be subject to enzymatic deprivation before it
reaches to its specific site of pharmacological action. Aerosols for
pulmonary drug delivery are transported from the mouth.
This is the main deposition mechanism forparticles >1 μm in the
A particle having a large momentum it may not able to follow the
altering direction of the inspired air as it transferred the bifurcations
and it will show result to collide with the airway walls as it
continues on its original course.
Description of particle deposition mechanisms at
an airway branching site
Impaction it mainly occurs near the bifurcations, certainly the
impaction of particles from tobacco smoke on the bifurcations may
be one cause whythese sites are often the foci for lung tumors.
The prospect of inertial impaction will be dependents upon particle
momentum, thus particles with higher densities or larger diameter
and those travelling in airstreams of higher velocity will show
By the settling under gravity the particles may deposited. It becomes highly important for
particles that reach airways where the airstream velocity is relatively low, e.g. the
bronchioles and alveolar region.
The fraction of particles depositing by this mechanism it may dependent upon the time the
particles use in these regions.
This is of minor significance for particles >1 μm.
Particles smaller than this size are displaced by a sequentially bombardment of gas
molecules, which may results in particle collision with the airway walls. The chances of
particle deposition by diffusion increases with the particle size decreases.
Brownian diffusion is also more common in regions where airflow is very low or absent,
e.g. in the alveoli.
Deposition: ie interception, is of important for fibers but it may not for drug
delivery.Generally Particles bigger than 10 μm will have impact in the upper airways and are
rapidly removed by swallowing, coughing and mucociliary processes.
The particles in the size range 0.5–5 μm may break away from impaction in the upper
airways and may
deposit by sedimentation and impaction in the lowerTB and A regions.
If the aerosol particle size is between the 3 and 5 μm then deposition it mainly occur in the
TB region. If the particles are smaller than the 3 μm then appreciable deposition in the A
region is likely to occur.
PHYSIOLOGICAL FACTORS AFFECTING PARTICLE
DEPOSITION IN THE AIRWAYS :
Each successful production of the tracheobronchial tree
produces airways of falling diameter and length.
Every bifurcation results in an increase possibility for impaction
and the decrease in airway diameter is associated with a
smaller displacement necessary a particle to make contact with
Inspiratory flow rate:-
When the inspiratory flow rate increases they enhance
deposition by impaction in the first few generations of the TB
region. The increase in flow not only increase particle
momentum but also result in an increase in turbulence, mostly
in the larynx and trachea, which itself will enhance impaction in
theproximal tracheo-bronchial region.
1) It is needle free pulmonary delivery.
2) It requires small and fraction of oral dose.
3) Low concentration in the systemic circulation are
associated with reduced systemic side effects.
4) Rapid Onset of action
5) Avoidance of gastrointestinal upset
6) Degradation of drug by liver is avoided in
pulmonary drug delivery .
1) Oropharyngeal deposition gives local side effect.
2) Patient may have difficulty using the pulmonary drug devices
1)In Asthma and COPD:
Asthma is a chronic lung that disease is characterized by
inflammation and narrowing of airways & it causes recurring
period so wheezing, shortness of breath, chest tightness and
coughing. For treatment of asthma for ex-levosalbutamo
linhalers which showgreater efficacy as compare tosalbutamol.
COPD means chronic obstructive pulmonary diseases. For the
treatment of COPD titropium inhalers are present in market.
2) pulmonary delivery inpatients on ventilators:
Now a days Baby mask is used aspatient device &. is attached
to spacer for small tidal volumes and low inspiratory flow rates
infant and young Childers.
We can easily give medication to child up to 2 years by using
baby mask .
3)In cystic fibrosis
Now a days cystic fibrosis is very common disease pulmonary
delivery played an important role in the treatment of CF for
decades. The main aim of aerosol system is to deliver drugs to
infants and children’s.
Ex:N-Acetylcysteine, Tobramycin-spray dried.
Diabetes is deficiency of insulin secretion or resistance. Insulin
inhalers would work much like asthma inhalers.
The products fall into two main groups the dry powder
formulations and solution, which are delivered through different
patented inhaler systems. E.g. Novel pMDI formulations for
pulmonary delivery of proteins
Ergotamine is the drug of choice of migraine & earlier it has been used
through inhalation (pulmonary route).
6)In Angina Pectoris:
Nitroglycerine is drug of choice for angina pectoris has been given
generally by sublingual route .
Isosorbide aerosol has also been reported useful in hypertensive crisis.
In United States inhalation therapy for angina-pectoris is very well
7) Role in vaccination :
Nearly 100 vaccines are approved in the U. S. About half of these
prevent respiratory infections, yet all are currently injected
Recently inhaled measles vaccine given by nebulizer.
As far back as the 1960, influenza experts tested aerosol flu vaccines.
RECENT TECHNOLOGIES OF
PULMONARY DRUG DELIVERY:
In jet nebulizers, an aerosol is prepared by a high velocity
air stream from a pressurized source directed against a thin layer
of liquid solution. Ultrasonic nebulizers include the vibration of a
piezoelectric crystal aerosolizing the solution.
The nebulizer can transport more drugs to the lungs than MDI
The most common disadvantage of nebulizer are lack of
possibility, higher costs of drug delivery as a result of the larger
need for assistance from healthcare professionals.
METERED DOSE INHALER (MDI):
These are the most common device for administration of
In this technique, a medication is mixed in a canister with
a propellant, and the preformed mixture is expelled in
exact measured amounts upon actuation of the device.
EX: Drugs which are administered through this device
1. CONTROLLED DRUG DELIVERY CONCEPTS
AND ADVANCES BY-S.P.VYAS & R.P.KHAR
2. MODERNPHARMACEUTICS FOUTH EDITION
BY- BANKER & RHODES
3. ADVANCE IN CONTROLLED AND NOVEL
DRUG DELIVERY BY-N.K. JAIN