Influence of storage conditions on the physical and release properties of piroxicam suppositories formulated with lipophilic bases
Abstract
This study investigated the effect of storage conditions on physical and release properties of lipophilic-based piroxicam suppositories with a view to determining the most desirable conditions for their storage. Piroxicam 20 mg suppositories were prepared by fusion method using cocoa butter, Witepsol H15® and Witepsol W35® to which 2 %w/w Tween 20® was added. Physical and dissolution properties of the suppositories were determined by established methods after preparation and at 4-month intervals for 12-month storage on the shelf (27.5 ± 0.9 °C to 32.5 ±0.8 °C) and in the refrigerator (4 ± 1 °C). The suppositories stored in the refrigerator hardened at the fourth month, with fat “blooming” observed on cocoa butter-based suppositories at 8th month. Melting points of cocoa butter-based suppositories remained below 37.5 °C on storage, while those formulated with Witepsol H15® and Witepsol W35® increased to 42.1 °C and 44.0 °C, respectively. Cocoa butter-based suppositories stored on the shelf showed decrease in melting range and mechanical strength compared with those stored in the refrigerator. There was increase in mechanical strength and disintegration time of the witepsol-based suppositories on aging. Release of piroxicam from witepsol bases decreased significantly (P < 0.05) on storage either in the refrigerator or on the shelf, while those formulated with cocoa butter base increased. In conclusion, piroxicam suppositories formulated with cocoa butter would require storage in the refrigerator, while long-term storage of those formulated with Witepsol H15® and Witepsol W35® in the refrigerator might not be desirable.
Keywords: Piroxicam suppositories; Lipophilic bases; Storage conditions; Physical properties; Release properties
Copyright of articles published shall reside exclusively with the Faculty of Pharmaceutical Sciences, University of Jos.
DECLARATION & COPYRIGHT TRANSFER
I/We the undersigned author(s) of article entitled
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………
Declare as follows:
- The manuscript submitted to Journal of Pharmacy & Bioresources is original and has not been and will be published, whole or in part, in print or electronic format, in any other journal. It is also not being currently considered for publication in any journal.
- The submitted manuscript is a joint decision of all the coauthors.
- Each author has participated sufficiently in the work to warrant his or her inclusion in the list of authors. To this end, each author takes responsibility for appropriate portions of the manuscript.
- Authors have obtained necessary approval to carry out the experiments on animals and human subjects. Approval certificates will be furnished, if required by publishers or editors of the journal.
- Authors do not have any conflict of interest (financial or otherwise) other than those declared.
- If the manuscript is accepted for publication, the authors transfer and assign copyright of the article referenced above to Journal of Pharmacy and Bioresources.
Name & Signature of authors
1. 2.
- 4.
- 6.
- 8.
Corresponding authors name address, affiliation and email: