Pre-Formulation Studies Essay

8. Pre-formulation Studies.
Preformulation studies are the first step in rational development of a dosage forms. It is the process of optimizing a drug through determination or definition of the physical and chemical properties are important in the formation of a stable, effective and safe dosage form. Preformulation studies start from the identification of active drug to the characterization of physical properties necessary for the designing of effective, safe and stable dosage form.
8.1 MOXIFLOXACIN
8.1.1.Appearance:
Light yellow or yellow powder, slightly hygroscopic
Slightly yellow to yellow powder
8.1.2.Drug Identification
Following tests are performed to identifyMoxifloxacin
A. Determination of wavelengthmaxima (λmax)
The ultraviolet

These studies indicate the polar and non-polar nature of the drug that is responsible for its in-vivo performance.The drug solution 10 µg/mL of Moxifloxacinadded in a mixture of distilled water (10 mL) and then n-octanol (10 mL) in a glass stopperd test tube. Test tube was gently shaken for 4 hr. After shaking, the aqueous phase was separated using a separating funnel and Moxifloxacin content was estimated UV-spectrophotometrically at 293 nm. The content of NMD in n-octanol layer was calculated using the initial content taken and content in distilled water. The partition coefficient of Moxifloxacin was calculated as follows-
Po/w = Co/Caq
8.1.5 Preparation of Calibration Curve
Calibration curve was prepared spectrophotometrically based on UV absorption at λmax 238 nm in PBS pH 6.8 for the quantitative estimation of Moxifloxacin.
A. Stock solution
An amount equivalent to 10 mg Moxifloxacin was accuratelyweighd and placed in a 10mL volumetric flask.10mL of phosphate buffer pH 6.8 and 0.5mL of 0.05% w/v solution of SLS added to prepare a 1000µg/mLstock solution of

9. Formulation and Product Development
MoxifloxacinHCl tablets were prepared by wet granulation method.
Step 1: Weighing and Blending - the active ingredient, gas generation agents, polymers, are Weighed and mixed.
Step 2: The wet granulate is prepared by adding the liquid binder/lubricant. The liquid solution can be either aqueous based or solvent based. In this formulation the binding solution is PVP solution is made.
Step 3: Screening the damp mass into granules.
Step 4: Drying the granules (in hot air oven at 600c for one hour).
Step 5: Dry screening: After the granules are dried, pass through a screen of smaller size than the one used for thewet mass to select granules of uniform size to allow even fill in the diecavity.
Step 6: Lubrication- A dry lubricant, gliding is added to the granules either by dusting over the spread-out granulesor by blending with the granules. It reduces the friction between the tablet and the walls of the die