Vin nn betamethason

Tabellae Betamethasoni

 

L vin nn cha betamethason.

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 betamethason, C22H29FO5, t 90,0 n 110,0% so vi hm lng ghi trn nhn.

 

Tnh cht

Vin mu trng hoc trng ng.

 

nh tnh

A. Lc mt lng bt vin nghin mn tng ng khong 25 mg betamethason vi 150 ml dicloromethan (TT) trong 30 pht, lc, ra dch lc bng 20 ml nc, cho dch lc qua phu cha natri sulfat khan (TT). Bc hi dch lc n kh v sy kh cn thu c 105 OC trong 2 gi. Ph hp th hng ngoi ca cn (Ph lc 4.2) phi tng ng vi ph hp th hng ngoi ca betamethason chun.

B. Trong phn nh lng, trn sc k t c dung dch th (1) phi c mt pic c thi gian lu tng ng vi thi gian lu ca pic betamethason trn sc k ca dung dch chun.

 

ng u hm lng

Cc vin nn c cha di 2mg betamethason phi p ng yu cu trong chuyn lun Th ng u hm lng (Ph lc 11.2).

Tin hnh bng phng php sc k lng (Ph lc 5.3) trong iu kin trnh nh sng.

Pha ng v thc hin cc iu kin sc k ging nh trong phn nh lng.

Dung dch chun: L dung dch c cha betamethason chun 0,0025% v hydrocortison 0,002% (cht chun ni) pha trong methanol 50% (TT).

Dung dch th : Nghin mt vin ch phm thm 20 ml hydrocortison 0,002% (cht chun ni) pha trong methanol 50% (TT, lc k trong 10 pht vi methanol 50% (TT) ri thm methanol 50% (TT) va 20 ml, lc qua mng lc 0,45 mm.

Tnh hm lng betamethason, C22H29FO5 , trong vin da theo din tch pic trn sc k thu c ca dung dch chun, dung dch th (2) v hm lng C22H29FO5 trong betamethason cht chun

nh lng

Tin hnh bng phng php sc k lng (Ph lc 5.3) trong iu kin trnh nh sng.

Pha ng: Nc - methanol (53: 47).

Dung dch chun: L dung dch c cha betamethason chun 0,0125% v hydrocortison 0,010% (cht chun ni) pha trong methanol 50% (TT).

Dung dch chun ni: Hydrocortison 0,010% pha trong methanol 50% (TT).

Dung dch th (1): Cn 20 vin xc nh khi lng trung bnh ca vin, nghin thnh bt mn. Cn chnh xc mt lng bt vin tng ng vi khong 2,5 mg betamethason, lc k trong 10 pht vi methanol 50% (TT) ri thm methanol 50% (TT) va 20 ml, lc qua mng lc 0,45 mm.

Dung dch th (2): Lm nh dung dch th (1) nhng thay dung mi methanol 50% (TT) bng dung dch chun ni .

iu kin sc k:

Ct thp khng g (20 cm 5 mm) c nhi pha tnh C (10 mm) (Spherisorb ODS 1 l thch hp).

Detector quang ph t ngoi, t bc sng 238 nm.

Tc dng: 1,4 ml/pht.

Th tch tim: 20 ml.

Cch tin hnh:

Tim ring bit dung dch chun v dung dch th .

Tnh hm lng betamethason, C22H29FO5 , trong vin da theo din tch pic trn sc k thu c ca dung dch chun, dung dch th (2) v hm lng C22H29FO5 trong betamethason cht chun.

Bo qun

Trong ng kn, trnh nh sng, nhit khng qu 30OC.

Hm lng thng dng

0,5 mg v 0,6 mg.