Stability studies on penicillin derivatives
Current analytical assay methods for ampicillin sodium and cloxacillin
sodium are discussed and compared, High Performance Liquid
Chromatography (H.P.L.C.) being chosen as the most accurate, specific
New H.P.L.C. methods for the analysis of benzathine cloxacillin~
benzathine penicillin V; procaine penicillin injection B.P.;
benethamine penicillin injection; fortified B.P.C.; benzathine
penicillin injection; benzathine penicillin injection, fortified
B.P.C.; benzath ine penicillin susp2nsion; ampicillin syrups and
penicillin syrups are described.
Mechanical or chen ical damage to COlUITU1 packings is often associated
with H.P.L.C. analysis. One type, that of channel formation, is
investigated. The high linear velocity of solvent and solvent pulsing
during the pumping cycle were found to be the cause of this damage.
The applicability of nonisotherrnal kinetic experiments to penicillin V
prep3.rations, including formulated p3.ediatric syrufS, is evaluated. A
new tyt::e of nonisotherrnal analysis, based on slope estimation and using
a "4K Random Access Memory (R..A.M.) microcanputer is described. The name
of the program written for this analysis is NJNISO.
The distribution of active penicillin in granules for reconstitution
into ampicillin and penicillin V syrups, and its effect on the
stability of the reconstituted products, are investigated. Changing the
dil uent used to reconsti tue the syrups was found to affect the
stability of the product.
Dissolution and stability of benzathine cloxacillin at pH2, pH6 and pH9
is described, wi th proposed dissolution mechanisms and kinetic
analysis to suppJrt these mechanisms. Benzathine and cloxacillin were
found to react in solution at pH9, producing an insoluble amide.