VIn nn pyrazinamid

Tabellae Pyrazinamidi

 

L vin nn cha pyrazinamid.

Ch phm phi p ng cc yu cu trong chuyn lun Thuc vin nn (Ph lc 1.20) v cc yu cu sau y:

 

Hm lng pyrazinamid, C5H5N3O, phi t 95,0 n 105,0% so vi hm lng ghi trn nhn.

 

Tnh cht

Vin mu trng.

 

nh tnh

A. Lc mt lng bt tng ng vi khong 0,25 g pyrazinamid vi 20 ml ethanol (TT), lc, bc hi dch lc ti kh v sy cn 105 oC trong 30 pht. Ph hng ngoi (Ph lc 4.2) ca cn phi ph hp vi ph hng ngoi i chiu ca pyrazinamid.

B. Lc mt lng bt vin tng ng vi khong 50 mg pyrazinamid vi 50 ml nc v lc. Pha long 1 ml dch lc thnh 100 ml vi nc. Ph hp th (Ph lc 4.1) ca dung dch thu c trong khong t 230 n 350 nm phi c 2 cc i bc sng 268 nm v 310 nm.

C. un si mt lng bt vin tng ng vi khong 20 mg pyrazinamid vi 5 ml dung dch natri hydroxyd 5 M (TT), s c mi amoniac bay ra.

 

ho tan (Ph lc 11.4)

Thit b: Kiu cnh khuy.

Mi trng ho tan: 900 ml nc.

Tc quay: 50 vng/pht.

Thi gian: 45 pht.

Cch tin hnh: Ly mt phn dung dch mi trng ho tan mu th, lc. Pha long dch lc vi nc c nng khong khong 10 mg pyrazinamid trong 1 ml. o hp th (Ph lc 4.1) ca dung dch thu c bc sng cc i 268 nm, dng nc lm mu trng. So snh vi dung dch pyrazinamid chun c nng tng ng pha trong nc. Tnh lng pyrazinamid, C5H5N3O, c ho tan t cc hp th ca dung dch th, dung dch chun v hm lng C5H5N3O trong pyrazinamid chun.

Yu cu: Khng c t hn 75% lng pyrazinamid so vi lng ghi trn nhn c ho tan trong 45 pht.

 

Tp cht lin quan

Khng c qu 0,2%.

Xc nh bng phng php sc k lp mng (Ph lc 5.4).

Bn mng: Silica gel GF 254.

Dung mi khai trin: Acid acetic bng - nc - n-butanol (20 : 20 : 60).

Dung dch th: Lc k mt lng bt vin tng ng vi 0,1 g pyrazinamid vi 50 ml hn hp cloroform - methanol (9 : 1), lc, bc hi trn cch thu n kh v ho tan cn trong hn hp dung mi trn thnh 10 ml.

Dung dch i chiu: Pha long 1 th tch dung dch th thnh 500 th tch bng hn hp cloroform - methanol (9 : 1).

Cch tin hnh: Chm ring bit ln bn mng 20 ml mi dung dch trn. Trin khai sc k n khi dung mi i c khong 15 cm. Ly bn mng ra kh ngoi khng kh v quan st ngay di nh sng t ngoi bc sng 254 nm. Bt k vt ph no trn sc k ca dung dch th cng khng c m mu hn vt chnh trn sc k ca dung dch i chiu.

 

nh lng

Cn 20 vin, tnh khi lng trung bnh vin v nghin thnh bt mn. Cn chnh xc mt lng bt vin tng ng vi khong 0,1 g pyrazinamid cho vo bnh nh mc 500 ml, thm 200 ml nc, yn 10 pht, thnh thong lc, sau lc siu m trong 10 pht ri thm nc n nh mc. Lc u, lc, b 20 ml dch lc u. Pha long 5,0 ml dch lc vi nc thnh 100,0 ml, trn u. o hp th (Ph lc 4.1) ca dung dch thu c bc sng cc i 268 nm, dng nc lm mu trng. So snh vi dung dch pyrazinamid chun c nng tng ng pha trong cng dung mi. Tnh hm lng pyrazinamid, C5H5N3O, trong vin t cc hp th ca dung dch th, dung dch chun v hm lng C5H5N3O trong pyrazinamid chun.

 

Bo qun

ng trong l nt kn, nhit khng qu 30 oC.

 

Loi thuc

Thuc chng lao.

 

Hm lng thng dng

500 mg.