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.