Study on Preformulation Parameters of Losartan Potassium

1. Study on Preformulation
Parameters of Losartan Potassium
And abide in your houses and do not display
yourselves as [was] the display of the former times
of ignorance. And establish prayer and give zakah
and obey Allah and His Messenger. Allah intends
only to remove from you the impurity [of sin], O
people of the [Prophet's] household, and to purify
you with [extensive] purification [33. Al-Ahzab:33].

2. Preformulation
Preformulation--
 is the first step in the rational development of dosage
forms
 can be defined as an investigation of physical and
chemical properties of a drug substance alone and when
combined with excipients

3. Objectives and Goals
Objectives:
 to develop most stable and bioavailable dosage forms
 creates useful information to the formulator to design
optimum drug delivery system
Goals:
 to determine the kinetic rate profile of drug substance
 to establish the compatibility of a drug with excipients

4. Preformulation Parameters
 organoleptic properties
 crystallinity
 powder flow property
 bulk density
 solubilization
 compressibility
 drug excipient compatibility
 partition co- efficient
 ionization constant
 dissolution

5. Losartan
Losartan is-
 a non peptide angiotensin II receptor antagonist
 used as an anti hypertensive drug
Figure : structure of losartan potassium

6. Mechanism of Losartan
inhibits the binding of Angiotensin II to AT I in many tissues
causes prevention of vasoconstrictive , asoconstrictive and
aldosterone secreting effects
results in decreased vascular resistance and blood pressure

7. Preformulation parameters of Losartan
 Color : White crystalline powder
 Angle of repose : showed a range of angle of repose from
24.75o to 28.30o
 Solubility: Freely soluble in water and
methanol
Soluble in iso propyl alcohol
Slightly soluble in acetonitrile
 Flow ability : Good to excellent flow ability

8. Continued…
 Hygroscopicity : Highly higroscopic and should keep
below 50% RH
 Melting point : 183.5- 184.5˚ C
 Drug polymer interaction : showed no interaction with
polymer
 Drug excipient interaction : no incompatibility with
excipients

9. Continued…
 Drug interaction :
i. Losartan + potassium supplements = Hyperkalemia
ii. Losartan + Lithium = Lithium toxicity
iii. Losartan + NSAID = Decreases effect of Losartan
iv. showed incompatibility with Amlodipine

10. Conclusion
Preformulation studies have a significant part to play in
removing formulation problems. It gives directions for
development of formulation in choice of drug form,
excipients, composition, etc. Hopefully, this present study of
losartan will be helpful for researchers for the development
of different dosage form of losartan potassium.