FORMULATION AND EVALUATION OF EXTENDED RELEASE MICROCAPSULES OF LAMIVUDINE - OBJECTIVES

 

OBJECTIVES

 

            The main objective of any drug therapy is to achieve a desire concentration of drug in blood or tissue, which is therapeutically effective and non toxic for an extended period of time. This can be achieved by proper design of sustained release dosage regimen. The microencapsulation is one among these which can be utilized successesfully to design the oral sustained release dosage form^{1, 2}.

 

            Lamivudine (Epivir) is used along with other medications to treat human immunodeficiency virus(HIV) infection. Lamuvudine (Epivir-HBV) is ued to treat hepatitis B infection. Lamivudine is in a class of medications called nucleoside reverse transcriptase inhibitors (NRTIs)³.

 

            .Lamivudine is a pyrimidene analogue reverse tanscriptase enzyme inhibitors active against HIV virus. It is metabolized to actice triphosphate from by multiple kinase. The triphosphate form completes with deoxycytidine triphosphate for binding reverse transcriptase and incorporation of 3-tc from viral DNA results in chain termination. Lamivudine is rapidly absorbed orally with 85% bioavailability and distributed widely in the body. Lamivudine is primarily 70% of the drug excreted unchanged in urine with elimination half life of 5-7 hrs^3,4.

 

            As per the through literature survey it is confirmed that very little work on Lamivudine microcapsule is reported. There are no reports found on microencapsulation of Lamivudine. Hence, the present study is aiming to design the microencapsulation dosage form of the Lamivudine, by utilizing naturally occurring olibanum gum resin after its suitable extraction.

The present work was an attempt:

1.      To develop Sustained release matrix tablets contains Lamivudine by using special excipient like  HPMC, EC and Magnesium stearate.

2.      To evaluate for the pre-compression characteristics of powder mixture like bulk density, flow property, angle of repose, compressibility index etc.

3.      To evaluate the post-compression characteristics of the tablet like hardness, friability, disintegration time, dispersion time, wetting time and water absorption ratio etc.

4.      To carry out in vitro dissolution studies of the tablet formulations.

5.      To carry out stability studies according to ICH guidelines.

 

PLAN OF WORK

METHOD OF COLLECTION OF DATA:

1.      The selected drug was characterized and evaluated for its physicochemical properties like solubility and compatibility with excipients.

2.      To identify the suitable excipients alone or in combine for further processing.

3.      To carry out pre-formulation studies like organoleptic properties, Bulk density, tapped density, Angle of repose, Compressibility index of the powder mixture (drug and excipients).

4.      To formulate various formulations of the drug containing different ratio of the polymer or in combination.

5.      To evaluate the compressed tablet for hardness, friability, disintegration time, In-vitro dispersion time, wetting time and In-vitro dissolution time, etc.

6.      The optimized formulation will be subjected to stability studies according to ICH guidelines.

7.      The data so obtained will be subjected for statistical analysis.

8.      The selected drug shall be characterized and evaluated for its physicochemical properties like solubility and compatibility with excipients.

9.      To identify the suitable excipients alone or in combine for further processing.

10.  To carry out pre-formulation studies like organoleptic properties, Bulk density, tapped density, Angle of repose, Compressibility index of the powder mixture (drug and excipients).

11.  To formulate various formulations of the drug containing different ratio of the hydrophilic polymer or in combination.

12.  To evaluate the compressed tablet for hardness, friability, disintegration time, In-vitro dispersion time, wetting time and In-vitro dissolution time, etc.

13.  The optimized formulation will be subjected to stability studies according to ICH guidelines.

14.  The data so obtained will be subjected for statistical analysis.

The preliminary data required for the experimental study was obtained from

1.      CD-Rom search available at National Center for Scientific Information (NCSI), Indian institute of Sciences (IISc), Bangalore.

2.      Journals,

3.      Analytical chemistry Books ,

4.      Library,

5.      Relevant Books,

6.      Internet Sources ,

7.      Scientific abstracts.