about imipenem

[amrit]

hi everybody,
I need information regarding the suitable HPLC conditions and commercially available column for Imipenem and Cilastatin and 'll be highly obliged to get the answer from the experts of the same

[zokitano]

Dear Amrit,

there are many different HPLC methods for imipenem and cilastatin

Methods for imipenem assay use different columns (also avaliable and common):
Examples:
1)
RP-8 150x4.6 mm (Microsorb)
Mobile phase: 1 mM KH2PO4 adjusted to pH 6.8 with 500mM NaOH
Flow rate: 1.5 mL/ min
Detection: UV, 300nm

2)
RP18 Hypersil ODS 100x4, 5 microns
Mobile phase: ACN: 10 mM ammonium acetate = 20: 80
Flow rate: 2 mL/min
Detection: UV, 300 nm

For cilastatin:
1)
RP-8 150x4.6mm, 5 micron
mobile phase: MeOH:water:100 mM pH 7 3-[morpholino]propanesulfonic acid buffer = 4:86:10
Detector: UV, 245nm

2)
C18 column (Bondapack)
mobile phase: isopropanol:water = 7:93 , adjusted to pH 3 with H3PO4
Flow rate: 1.5 mL/min
Detection: UV, 210 nm

Best regards

[amrit]

dear zokitano,
thank you for your answer. actually i was asking for those in combination. would it be same means trying as for individual or there is specific reported for combination of imipenem and cialstatin

[amrit]

what is specific advantage in working with morpholino]propanesulfonic acid as buffer for HPLC, could it be repalced by other one?

whtat abt sodium hexane sulfonate?

[zokitano]

Dear Amrit,

3-[morpholino]propanesulfonic acid and sodium hexane sulfonate are ion-pairing agents. I haven't so far worked with morpholino-agent.
I found these HPLC methods for this purpose, I haven't tried running them on HPLC. I am familiar with hexane sulfoniate, and it can be replaced with heptane sulfonate or other hydrocarbon-sulfonate, but with the change of the ion-pairing agent you'll observe retention time shift of your analytes (compared with the parent method).
If you use heptane or other higher alkane-sulfonate with C18 RP retention times will become greater and vice versa.

Best regards

[amrit]

Dear zokitano,
would you please like to provide the references where from you have provide the methods for imipenem and cilastatin?

[zokitano]

Dear Amrit,

those methods can be found in the book: HPLC methods for Pharmaceutical Analysis by George Lunn.

Best regards,
Zoran

[Mark Tracy]

Morpholinopropanesulfonate is a zwitterionic buffer for pH 6.5--8.0, and not a very good ion pairing agent. It is well liked because of its low temperature coefficient, low UV absorbance, and low biological activity.

[Kamal Bhati]

The method for Imipenem and Cilastatin can be found in the USP 29 and 30 volumes. The drug is now pharmacopoeial with the name Imipenem and Cilastatin for Injection and the method is quiet specific for both the analytes. There is no need to deviate from the chromatographic parameters and column type since you will find the desired separation easily with the USP method.

Kamal Bhati

[Uwe Neue]

To be specific: the column used is a microBondapak C18 column. Other columns will not give you the same results.

[amrit]

i am using supelco discovery C-18 column.