DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Bayrho-D (Rho-D Immune Globulin Human) - Description and Clinical Pharmacology

 
 



DESCRIPTION

Rho(D) Immune Globulin (Human) -- BayRho-D® Full Dose treated with solvent/detergent is a sterile solution of immune globulin containing antibodies to Rho(D) for intramuscular administration; it contains no preservative. BayRho-D Full Dose is prepared by cold ethanol fractionation from human plasma. The immune globulin is isolated from solubilized Cohn fraction II. The fraction II solution is adjusted to a final concentration of 0.3% tri-n-butyl phosphate (TNBP) and 0.2% sodium cholate. After the addition of solvent (TNBP) and detergent (sodium cholate), the solution is heated to 30°C and maintained at that temperature for not less than 6 hours. After the viral inactivation step, the reactants are removed by precipitation, filtration and finally ultrafiltration and diafiltration. BayRho-D Full Dose is formulated as a 15-18% protein solution at a pH of 6.4-7.2 in 0.21-0.32 M glycine. BayRho-D Full Dose is then incubated in the final container for 21-28 days at 20-27°C.

The potency is equal to or greater than that of the U.S. Food and Drug Administration Reference Rho(D) Immune Globulin. Each single dose vial or syringe contains sufficient anti-Rho(D) (approximately 300 µg *) to effectively suppress the immunizing potential of 15 mL of Rho(D) positive red blood cells. 2-4

The removal and inactivation of spiked model enveloped and non-enveloped viruses during the manufacturing process for BayRho-D Full Dose has been validated in laboratory studies. Human Immunodeficiency Virus, Type 1 (HIV-1), was chosen as the relevant virus for blood products; Bovine Viral Diarrhea Virus (BVDV) was chosen to model Hepatitis C virus; Pseudorabies virus (PRV) was chosen to model Hepatitis B virus and the Herpes viruses; and Reo virus type 3 (Reo) was chosen to model non-enveloped viruses and for its resistance to physical and chemical inactivation. Significant removal of model enveloped and non-enveloped viruses is achieved at two steps in the Cohn fractionation process leading to the collection of Cohn Fraction II: the precipitation and removal of Fraction III in the processing of Fraction II + IIIW suspension to Effluent III and the filtration step in the processing of Effluent III to Filtrate III. Significant inactivation of enveloped viruses is achieved at the time of treatment of solubilized Cohn Fraction II with TNBP/sodium cholate.


*A full dose of Rho(D) Immune Globulin (Human) has traditionally been referred to as a "300 µg" dose and this usage is employed here for convenience in terminology. It should not be construed as the actual anti-D content. Each full dose of Rho(D) Immune Globulin (Human) must contain at least as much anti-D as 1 mL of the U.S. Reference Rho(D) Immune Globulin. Studies performed at the FDA have shown that the U.S. Reference contains 820 international units (IU) of anti-D per mL. When the conversion factor determined for the International (WHO) Reference Preparation1 is used, 820 IU per mL is equivalent to 164 µg per mL of anti-D.

CLINICAL PHARMACOLOGY

BayRho-D Full Dose is used to prevent isoimmunization in the Rho(D) negative individual exposed to Rho(D) positive blood as a result of a fetomaternal hemorrhage occurring during a delivery of an Rho(D) positive infant, abortion (either spontaneous or induced), or following amniocentesis or abdominal trauma. Similarly, immunization resulting in the production of anti-Rho(D) following transfusion of Rh positive red cells to an Rho(D) negative recipient may be prevented by administering Rho(D) Immune Globulin (Human). 5,6

Rh hemolytic disease of the newborn is the result of the active immunization of an Rho(D) negative mother by Rho(D) positive red cells entering the maternal circulation during a previous delivery, abortion, amniocentesis, abdominal trauma, or as a result of red cell transfusion.7,8 BayRho-D Full Dose acts by suppressing the immune response of Rho(D) negative individuals to Rho(D) positive red blood cells. The mechanism of action of BayRho-D Full Dose is not fully understood.

The administration of Rho(D) Immune Globulin (Human) within 72 hours of a full-term delivery of an Rho(D) positive infant by an Rho(D) negative mother reduces the incidence of Rh isoimmunization from 12%-13% to 1%-2%. 9

The 1%-2% treatment failures are probably due to isoimmunization occurring during the latter part of pregnancy or following delivery.10 Bowman and Pollock11 have reported that the incidence of isoimmunization can be further reduced from approximately 1.6% to less than 0.1% by administering Rho(D) Immune Globulin (Human) in two doses, one antenatal at 28 weeks' gestation and another following delivery.

In a clinical study in eight healthy human adults receiving another hyperimmune immune globulin product treated with solvent/detergent, Rabies Immune Globulin (Human), BayRab®, prepared by the same manufacturing process, detectable passive antibody titers were observed in the serum of all subjects by 24 hours post injection and persisted through the 21 day study period. These results suggest that passive immunization with immune globulin products is not affected by the solvent/detergent treatment.

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017