PHENOBARBITAL

Phenobarbitalum

 

 

 

 

 

 

 

C12H12N2O3 P.t.l: 232,2

 

Phenobarbital la acid 5-ethyl-5-phenylbarbituric, phai cha t 99,0 en 101,0% C12H12N2O3, tnh theo che pham a lam kho.

Tnh chat

Tinh the khong mau hay bot ket tinh trang, khong mui.

Rat kho tan trong nc, hi tan trong cloroform, tan trong ether, de tan trong ethanol 96%. Tao thanh hp chat tan trong nc vi hydroxyd, carbonat kiem va vi amoniac.

nh tnh

Co the chon mot trong hai nhom nh tnh sau:

Nhom I: A, B.

Nhom II: B, C, D.

A. Xac nh iem chay (Phu luc 6.7) cua che pham va cua hon hp ong lng che pham vi phenobarbital chuan (C). iem chay cua che pham va cua hon hp phai khoang 176 oC. S khac biet ve iem chay cua 2 mau tren khong c qua 2 oC.

B. Pho hong ngoai (Phu luc 4.2) cua che pham phai phu hp vi pho hong ngoai cua phenobarbital chuan (C).

C. Phng phap sac ky lp mong (Phu luc 5.4).

Ban mong: Silica gel GF254 (TT).

Dung moi khai trien: la lp di cua hon hp gom Amoniac am ac - ethanol 96% - cloroform (5 : 15 : 80).

Dung dch th: Hoa tan 0,1 g che pham trong ethanol 96% (TT) va pha loang thanh 100 ml vi cung dung moi.

Dung dch oi chieu: Hoa tan 0,1 g phenobarbital chuan (C) trong ethanol 96% (TT) pha loang thanh 100 ml vi cung dung moi.

Cach tien hanh: Cham rieng biet len ban mong 10 l moi dung dch tren. Trien khai sac ky ti khi dung moi i c khoang 18 cm. Quan sat ngay ban mong di anh sang t ngoai bc song 254 nm. Vet chnh cua sac ky o thu c t dung dch th phai gion ve v tr va kch thc vi vet chnh cua sac ky o thu c t dung dch oi chieu.

D. Phan ng ac trng cua barbiturat co hydro nhom NH khong b thay the (Phu luc 8.1).

o trong va mau sac cua dung dch

Hoa tan 1,0 g che pham trong hon hp gom 4 ml dung dch natri hydroxyd 2 M ( TT) va 6 ml nc. Dung dch phai trong (Phu luc 9.2) va mau khong c am hn mau mau V6 (Phu luc 9.3 phng phap 2).

Gii han acid

un soi 1,0 g che pham vi 50 ml nc trong 2 phut, e nguoi roi loc. Them 0,15 ml dung dch o methyl (TT) vao 10,0 ml dch loc, dung dch co mau vang cam. e chuyen sang mau vang, the tch dung dch natri hydroxyd 0,1 N (C) s dung khong c qua 0,1 ml.

Tap chat lien quan

Khong c qua 0,5%.

Xac nh bang phng phap sac ky lp mong (Phu luc 5.4).

Ban mong: Silica gel GF254 (TT).

Dung moi khai trien: La lp di cua hon hp amoniac am ac - ethanol 96% - cloroform (5 : 15 : 80).

Dung dch th: Hoa tan 1,0 g che pham trong ethanol 96% (TT) va pha loang thanh 100 ml vi cung dung moi.

Dung dch oi chieu: Pha loang 0,5 ml dung dch th thanh 100 ml bang ethanol 96% (TT).

Cach tien hanh: Cham rieng biet len ban mong 20 l moi dung dch tren. Trien khai sac ky ti khi dung moi i c khoang 15 cm. Quan sat ngay ban mong di anh sang t ngoai bc song 254 nm, phun thuoc th diphenylcarbazon thuy ngan (TT). e kho ban mong ngoai khong kh, phun dung dch kali hydroxyd trong ethanol (TT) va mi pha. Say ban mong 100 105 oC trong 5 phut, quan sat ngay tc khac. Khi quan sat di anh sang t ngoai hoac sau khi phun thuoc th, bat c vet phu nao tren sac ky o thu c t dung dch th khong c am mau hn vet tren sac ky o thu c t dung dch oi chieu.

Mat khoi lng do lam kho

Khong c qua 0,5% (Phu luc 9.6).

(1,000 g; 100 105 oC; 2 gi).

Tro sulfat

Khong c qua 0,1% (Phu luc 9.9, phng phap 2).

Dung 1,0 g che pham.

nh lng

Hoa tan 0,100 g che pham trong 5 ml pyridin (TT), them 0,5 ml dung dch thymolphtalein (TT) va 10 ml dung dch bac nitrat 8,5% trong pyridin (TT). Chuan o bang dung dch natri hydroxyd 0,1 N trong ethanol ( C) en khi co mau xanh lam hoan toan . Song song lam mau trang.

1 ml dung dch natri hydroxyd 0,1 N trong ethanol (C) tng ng vi 11,61 mg C12H12N2O3.

Bao quan

Trong chai lo kn.

Loại thuốc

An than, chong co giat.

Che pham

Con thuoc, vien nen.