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Crystal modifications and dissolution rate of piroxicam
Lim Yee Lyn1, Huan Wen Sze, Adhiyaman Rajendran
1School of Pharmacy and Health Sciences, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia.
Acta Pharmaceutica (Zagreb, Croatia)
|December 29, 2011
Summary
Developing new piroxicam crystal forms with PEG 4000 and PVP K30 improved drug dissolution and solubility. Cubic crystals enhanced solubility, while needle forms improved dissolution rates for this nonsteroidal anti-inflammatory drug.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Physical Chemistry
Background:
- Piroxicam, a nonsteroidal anti-inflammatory drug (NSAID), suffers from poor aqueous solubility and exhibits polymorphism.
- Polymorphism can significantly impact a drug's bioavailability, affecting its therapeutic efficacy.
Purpose of the Study:
- To develop novel polymorphs of piroxicam with enhanced solubility and dissolution rates.
- To investigate the effect of crystal modification using polyethylene glycol 4000 (PEG 4000) and polyvinylpyrrolidone K30 (PVP K30).
Main Methods:
- Crystal modification techniques including solvent evaporation (method I) and slow crystallization (method II) using various solvent mixtures.
- Characterization of modified piroxicam crystals using X-ray powder diffractometry (XRPD), FT-IR spectrophotometry, and differential scanning calorimetry (DSC).
- Evaluation of dissolution and solubility profiles of modified crystals compared to pure piroxicam.
Main Results:
- Method I yielded both needle and cubic piroxicam crystals. Needle forms enhanced dissolution but not solubility; cubic forms showed improved solubility with similar dissolution to untreated piroxicam.
- Method II produced cubic crystals with improved dissolution rates and no significant change in solubility.
- XRPD and FTIR analyses indicated structural differences in modified crystal forms, correlating crystal shape with physicochemical properties.
Conclusions:
- Crystal modification of piroxicam using PEG 4000 and PVP K30 can yield polymorphs with improved dissolution and solubility characteristics.
- The shape of the piroxicam crystals (needle vs. cubic) and the crystallization method significantly influence their dissolution and solubility profiles.
- These findings offer a promising approach for enhancing the bioavailability of piroxicam through solid-state modifications.
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