in an embodiment of the present invention , the granules of lamivudine and zidovudine may be prepared by a separate granulation involving granulation of lamivudine and zidovudine separately or granulating lamivudine and zidovudine in a single granulation process . in another embodiment of the present invention , the granules of lamivudine , zidovudine and nevirapine further comprise one or more pharmaceutical excipients . in another embodiment of the present invention , the pharmaceutical excipients selected from diluents , binders , disintegrants , glidants and lubricants . suitable diluents used according to the present invention are selected from mannitol , lactose , microcrystalline cellulose , maltitol , maltodextrin , maltose , starch , calcium carbonate , calcium phosphate dibasic , calcium sulfate , and dextrates or a combination thereof . suitable binders used according to the present invention are selected from hydroxy propyl cellulose , hydroxypropyl methylcellulose , gelatin , hydroxy ethyl cellulose , povidone , starch and methylcellulose or a combination thereof . suitable disintegrants used according to the present invention are selected from sodium starch glycolate , croscarmellose sodium , crospovidone , hydroxypropyl cellulose , magnesium aluminum silicate , pregelatinized starch , cornstarch , sodium carboxymethyl cellulose , or a combination thereof . suitable glidants used according to the present invention are selected from magnesium trisilicate , talc , tribasic calcium phosphate , glyceryl monostearate , glyceryl stearate and silica dioxide or a combination thereof . suitable lubricants used according to the present invention are selected from calcium stearate , magnesium stearate , hydrogenated vegetable oil , stearic acid , magnesium aluminum silicate or a combination thereof . the granules according to the present invention may be prepared by wet granulation or dry granulation such as compaction / slugging . the wet granulation process according to the present invention comprises the steps of a ) granulating lamivudine and zidovudine or nveirapine and optionally filler , disintegrant , with solvent alone or a solution of binder , c ) sieving the dried granules to obtain uniform granules of lamivudine and zidovudine or nveirapine . the solvents used according to the present invention may be selected from water , isopropyl alcohol , acetone or combination thereof . the tablets according to present invention may optionally be coated to prevent the degradation of lamivudine from light . the polymers used for coating selected from hydroxypropyl methylcellulose , hydroxypropyl cellulose , xanthan gum or a combination there of . in another embodiment of the present invention , the solid dosage from may be in the form of tablets , bilayered tablets , and capsules . the following examples further exemplify the invention and are not intended to limit the scope of the invention . it is obvious to those skilled in the art to find out the composition for other dosage forms and substitute the equivalent excipients as described in this specification or with the one known to the industry . s . no . ingredients quantity per unit ( mg ) 1 lamivudine 150 . 00 2 zidovudine 300 . 00 3 nevirapine anhydrous 200 . 00 4 microcrystalline cellulose 192 . 00 5 sodium starch glycolate 4 . 00 6 lactose monohydrate 120 . 00 7 povidone 3 . 00 extragranular ingredients 8 sodium starch glycolate 15 . 00 9 colloidal silicone dioxide 8 . 00 10 magnesium stearate 8 . 00 tablet weight 1000 film coating 11 opadry 13b58802 30 . 00 i ) sifted and blended nevirapine , sodium starch glycolate , microcrystalline cellulose and lactose monohydrate , i ) sifted and blended sodium starch glycolate , magnesium stearate , colloidal silicone dioxide , ii ) blended the granules of lamivudine plus zidovudine obtained in step ( a ) and granules of nevirapine obtained in step ( b ) with the blend of step ( i ), iii ) lubricated the blend of step ( ii ) with magnesium stearate and compressed into tablets or filled into capsules and s . no ingredients quantity per unit ( mg ) 1 lamivudine 150 . 0 2 zidovudine 300 . 0 3 microcrystalline cellulose 250 . 0 4 nevirapine 200 . 0 5 lactose monohydrate 47 . 0 6 povidone k30 3 . 0 8 purified water qs extragranular stage 10 sodium starch glycolate 30 . 0 11 colloidal silicon dioxide 12 . 5 12 magnesium stearate 7 . 5 tablet weight ( mg ) 1000 . 0 coating 13 opadry 13b58802 white ih 30 . 00 14 purified water usp q . s . coated tablet weight 1030 . 00 i ) sifted and blended sodium starch glycolate , magnesium stearate , colloidal silicone dioxide , ii ) blended the granules of lamivudine plus zidovudine obtained in step ( a ) and granules of nevirapine obtained in step ( b ) with the blend of step ( i ), iii ) lubricated the blend of step ( ii ) with magnesium stearate and compressed into tablets or filled into capsules and s . no . ingredients quantity per unit ( mg ) granulation i intragranular stage 1 lamivudine 150 . 0 2 zidovudine 300 . 0 3 microcrystalline cellulose 114 . 5 4 sodium starch glycolate 10 . 0 5 purified water qs extragranular stage 6 sodium starch glycolate 11 . 0 7 colloidal silicon dioxide 5 . 0 8 magnesium stearate 5 . 0 granulation ii intragranular stage 9 nevirapine 200 . 0 10 lactose monohydrate 100 . 0 11 microcrystalline cellulose 86 . 5 12 povidone k30 3 . 0 13 quinoline yellow 0 . 5 14 purified water qs extragranular stage 15 sodium starch glycolate 8 . 0 16 colloidal silicon dioxide 3 . 5 17 magnesium stearate 3 . 0 i ) sifted and blended lamivudine , zidovudine , sodium starch glycolate microcrystalline cellulose , iv ) dried granules were blended with sodium starch glycolate , colloidal silicon dioxide , iv ) dried granules were blended with sodium starch glycolate , colloidal silicon dioxide , i ) blend ( a ) and ( b ) are filled into capsules or compressed into bilayered tablets . s . no . ingredients quantity per unit ( mg ) 1 lamivudine 150 . 00 2 zidovudine 300 . 00 3 nevirapine anhydrous 200 . 00 4 microcrystalline cellulose 184 . 00 5 sodium strach glycollate 4 . 00 6 lactose monohydrate 120 . 00 7 povidone 3 . 00 8 hypromellose 8 . 00 extragranular ingredients 9 sodium starch glycolate 15 . 00 10 colloidal silicone dioxide 8 . 00 11 magnesium stearate 8 . 00 tablet weight 1000 film coating 12 opadry 13b58802 30 . 00 [ a ] microcrystalline cellulose was sifted through a suitable mesh and divided into 3 equal parts , i ) sifted and blended nevirapine , sodium starch glycolate , lactose monohydrate and microcrystalline cellulose , i ) sifted and blended sodium starch glycolate , magnesium stearate , colloidal silicon dioxide , ii ) blended the granules of lamivudine obtained in step ( b ), zidovudine obtained in step ( c ) and nevirapine obtained in step ( d ) with blend of step ( i ), iii ) lubricated the blend of step ( ii ) with magnesium stearate and compressed into tablets or filled into capsules and the tablets were subjected to an in vitro dissolution method to determine the rate at which the lamivudine , zidovudine and nevirapine was released from the tablets . the tablets were placed into a dissolution medium of 0 . 01 n hcl and stirred with paddles at 50 rpm ( usp 2 apparatus ). the dissolution profile is given in table 1 .
the present invention relates to the stable pharmaceutical dosage forms of combination of antiretroviral agents . more particularly , the present invention relates to stable pharmaceutical dosage forms of lamivudine , zidovudine and nevirapine , prepared by granulation technology .