Date post: | 17-Jan-2017 |
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PREPARED BY:BHAVI GANDHI
LOCAL DRUG DELIVERY
GUIDED BY : DR.MAYANK PARAMAR DR.BANSARI SHAH DR.MAYUR PARAMAR
Content:IntroductionHistorical perspectiveObjectivesIndicationsContraindicationsAdvantagesDisadvantagesClassificationLocal drug delivery agentsConclusion
Introduction:Periodontal disease is associated with bacteria &
treatment by chemotherapeutic agents appears to be appropriate
Chemotherapeutic agents may be administered –systemically or delivered locally.
The term drug delivery covers a broad range of techniques used to get therapeutic agents into the human body.
When drug is delivered as a conventional dosage form such as a tablets, the dosing interval is much shorter than half life of the drug resulting in a no. of limitations associated with such a conventional dosage forms.
Historical perspective:W.D.Miller in the 1880 suggested the use of an
antimicrobial mouthrinse to aid in fighting what was then known as ‘pyorrhea alveolaris’
The concept of targeted drug delivery had its origin in the 1970’s based on the theory that if one could substantially improve the cellular specificity of a drug there would be an accompanying significant improvement in the therapeutic index;I,e,efficacy to side effects.
Dr.Max Goodson (1979) first proposed the concept of controlled release local delivery of therapeutic agents for the treatment of periodontitis.
Objective:The use of a local antimicrobial is to
prevent or control microbial induced inflammation in an effective concentration & be maintained there long enough for the desired effect to be accomplished without causing any side effect.
The limited efficacy of mouth rinsing & irrigation in deep periodontal pocket led to the development of alternative delivery systems.
The main aim of the drug delivery system is to direct antimicrobials to the infection sites & main effective level of drugs for sufficient period of time without eliciting any major side effects.
LOCAL DRUG DELIVERY SYSTEM:
Indications:As an adjunct in the treatment of few localized
non responding sites in an otherwise controlled patient.
In ailing & failing implant cases.In medically compromised patients where
surgical procedures are not recommended.Periodontal abscess.Periodontal maintenance therapy.Patient with gastrointestinal intolerance to
systemic drug medication.
Contraindications:Patients with history of allergy to a particular
antimicrobial agentsIn pregnancy & lactating periods.Children under the age of 12 years.Patients with complete renal failure.Patients susceptible to infective endocarditis.
Advantages:High concentration in subgingival sites.Independent of patient complianceDoes not harm the symbolic useful
microflora of gastrointestinal tract.Systemic intolerance is bypassed.
Disadvantages:Difficulty in placing of therapeutic
concentrations of the antimicrobial agents in deeper sites.
Has to be professionally placed or if manually placed, requires manual dexterity & patient compliance.
Complete drug penetration is not possible & extra pocket sites are unaffected.
Classification of local antimicrobial therapy in periodontics
• LANGER & PEPPAS (1988) Based on their mechanism of action1.Diffusion controlled systems -reservoirs (membrane devices) -matrices (monolithic device)2.Chemically controlled systems -bio-erodible systems -pendant chain systems3.Swelling controlled systems4.Magnetically controlled systems
LOCAL DELIVERY AGENTSLocally delivered antimicrobial agents are available
adjuncts to scaling & root planing & as aid in the control of bacterial growth on barrier membrane.
When placed into periodontal pockets, they reduced the subgingival microflora, probing depths & clinical sign of inflammation.
A report on locally delivered agents prepared by the American Academy of Periodontology stated “the clinician’s decision to use locally delivered agents should be based upon a consideration of clinical findings, the patient’s dental & medical history, scientific evidence, patient preference & advantages & disadvantages of alternative therapies.”
Subgingival chlorhexidine:A resorable delivery system has been tested for
subgingival placement of chlorhexidine gluconate with positive clinical results.
Periochip is a small chip (4.0×5.0×0.35mm) composed of a biodegradable hydrolyzed gelatin matrix, cross-linked with glutaraldehyde & also containing glycerin & water, into which 2.5mg of chlorhexidine gluconate has been incorporated per chip.
This delivery system releases chlorhexidine & maintains drug concentrations in the GCF greater than 100µg/ml for at least 7 days, concentrations well above the tolerance of most oral bacteria.
Chips were placed in target sites with probing depth of 5 to 8 mm at baseline that bled on probing & again at 3 & 6 months if probing depth remained at 5mm or greater.
Sites in control subjects received either a placebo chip(inactive) with scaling & root planing alone.
Sites in test subject received either a chlorhexidine chip (active) with scaling & root planing or scaling & root planing alone.
Advantages of periochip:Very easy & convenient to use. Takes second to place in
any pocket.Highly effective, safe , well tolerated.Painless to the patient. In some instances there may be
minor discomfort in the first 24 hrs.No restrictions on eating or oral hygiene after chip
insertion.All quadrants can be treated at the some visit.Does not affect taste or stain teeth.Maintain effective- concentration of chlorhexidine in the
pocket up to 10 days-125µg/ml.Delivers effective dosage even to the base of the
pocket.
Subgingival doxycycline:A gel system using syringe with 10%
doxycycline (atridox) is available.
Tetracycline (Actisite)Fiber of 23 cm in length that has 12.7 mg
tetracycline hydrochloride.Pocket measuring ≥5 mm that bleed on
probing.Fiber is inserted into the pocket.Some control saliva is needed.Should contact the pocket base.Surgical dressing is not necessary.Removed 7-1o days after placement.
Subgingival minocycline:A locally delivered, sustained release form of
minocycline is available.The 2%minocycline is encapsulated into
bioresorable microspheres in gel carrier.
Subgingival metronidazole:A topical medication containing an oil-based
metronidazole 25% dental gel.It is applied in viscous consistency to the
pocket , where it is liquidized by the body heat & then hardens again, forming crystals in contact with water.
As a precursor, the preparation contains metronidazole-benzoate, which is converted into the active substance by esterase in GCF.
Two 25% gel application at a 1 week interval has been used.
Antimicrobial agent
Product name nature Dosage form
Doxycycline Atridox Biodegradable Mixture in syringe
Tetracycline Actisite Nonresorable Fibers
Metronidazole Elyzol Biodegradable Mixture in syringe
Minocycline ArestinDentamycinPeriocline
Biodegradable Mixture in syringe
Chlorhexidine Periochip Biodegradable Chip device
Local drug delivery system in periodontal
therapy
Frequently used local Antimicrobials with dosage specificationDrug Dosage Release periods in
daysActisite 12.7 mg/9 inch fiber
of diameter 5mm10
Atridox 10%Periochip 2.5 mg of
chlorhexidine gluconate
7
Conclusion:Considering various factors of cost
effectiveness , efficacy, potential advantages & disadvantages it can be concluded that local drug delivery could serve as a potent in periodontal chemotherapy & at the same time a valuable adjunct to mechanotherapy , but its use as a monotherapy agent.