An innovative development in the delivery of medication to the eyes
One example of such device is the ocuset system alzaInc
The insert unit is designed to provide for the release of medication at predetermined & predictable rates permitting the elimination of frequent dosing by patient ,ensuring night time medication , & providing a better means of patient compliance
The ensert is elliptical with dimentions of 13.4, 5.7 mm & 0.3 mm in thickness
The insert is flexible & multilayered structure consisting of a drug containing core surrounded on each side by a layer of copolymer memberanes through which the drug diffuses at constant rate
The rate of drug diffusion is controlled by the polymer composition , the memberane thickness , & the solubility of the drug
The devices & sterile & donot contain preservatives
Inserts containing pilocarpine are widely used in glucoma therapy
After placement in cinjunctival sac , the inserts are designed to release medication at the desired rates over a 7 days period at which time they are removed & replaced with new one
LACRISERT
mercK is another example of an opthalmic insert ; asteril translusent rod shaped , water soluble form of hydroxypropyl cellulose . the product is inserted into the inferior cul-de-sac of the eye of patients with dry eye states . The insert acts to stabilize & hicken the pre corneal tear film to delay its breakup ..Use of the insert once or twice daily is recommended . following administration ,the inserts soften & sllowly dissolve
types of ocular inserts
1.Erodible ocular insers :
Are soluble films containing the drug dispersed in a polymeric matrix
They are inserted in the cul-du-sac beneath the eyelid where they will slowly dissolve & release the drug
They increase the ocular contact time of the drug leading to increase un its absorption & prolongation in its activity
Several water soluble polymers have been used in these inserts such as sodium alginate , gelatin , polyvinyl pyrrolidine
Example of drug incorporated in these inserts are pilocarpine & antibiotic
Since these inserts are unit dose system , they contain no preservative
2. Non-erodible ocular inserts
Are soft flexible elliptical-shaped disks which are designed to be inserted in the cul-du-sac bebeath the eyelid to continuously release the drug for prolonged period of time which may reach up to 7 days
After the insert becomes exhausted of its content , it must be removed from the eye
The non-erodible insert is composed of 3 component :
a) Drug reservoir containing the drug dispersed in alginic acid matrix
b) Apolymer memberan to control the drug release & made of ethylene\vinyl acetate copolymer which is a hydrophobic polymer non irritant to the eye
c) An annular ring surrounding the drug reservoir & made of ethylene\vinyl acetate copolymer memberane impregnated with titanium dioxide to form a white border to allow visibility during handling & insertion
Pilocarpine is an example of non-erodible ocularinsert ,they have 2 forms : pilo -20 & pilo-40 ocuset which designed to release pilocarpine in the range of 20 &40 microgram\hour
التعليقات
To apply the system, wash hands first.
Tilt your head back, gaze upward and pull down the lower eyelid to make a pouch.
Place the system into the pouch.
Blink a few times and roll your eye to move the insert into place.
Practice inserting and removing the system in the doctor s office where you can be shown the proper technique.
Damaged or deformed systems should not be used or kept in the eye.
Replace with a new system.
Side Effects
Headache, brow ache, temporary burning or stinging, or increased mucus production may occur initially.
These effects should disappear as your body adjusts to the medication.
Inform your doctor if you develop: changes in vision, eye pain, nausea, vomiting, sweating, increased salivation, diarrhea.
Also contact your doctor if blurred vision persists more than several hours in the morning after bedtime use.
If you notice other effects not listed above, contact your doctor or pharmacist.
Precautions
Before using Ocusert Pilo-20, tell your doctor if you have: other eye problems, asthma, intestinal disease, ulcers, low or high blood pressure, heart disease, an overactive thyroid gland, seizures, Parkinson s disease.
Before having surgery with a general anesthetic, tell the doctor or dentist that you use Ocusert Pilo-20.
Use caution if driving or performing duties requiring clear vision.
Ocusert Pilo-20 may cause vision problems in poor light.
Use caution especially when driving at night.
Ocusert Pilo-20 should be used during pregnancy only if clearly needed.
It is not known if Ocusert Pilo-20 appears in breast milk.
Consult with your doctor before breast-feeding.
Do not allow anyone else to use Ocusert Pilo-20.
Missed Dose
If you should miss a dose, apply as soon as remembered unless it is almost time for the next dose.
In that case, skip the missed dose and resume your usual dosing schedule.
Do not double-up the dose to catch up.
Drug Interactions
Ocusert Pilo-20 can affect the way your body responds to other drugs.
Tell your doctor what prescription and nonprescription drugs you are taking.
Do not start or stop any medicine without doctor or pharmacist approval
.
The ocusert provide a continious control of the intra-ocular pressure
The ocusert is adminstered only once per week & this will imporve patient compliance
The ocusert contain no preservative so they will be suitable for patients sensitive to preservatives in opthalmic solutions
It may be inconvenient for the patient to retain the ocusert in the eye for the full 7 days
The ocusert must be checked periodically by the patient to see that the unit is still in place
و بالنسبة لهل الشكل الصيدلاني لحد الآن للأسف مانزل عننا ...على حسب علمي ..
شكرا لك موضوع مميز