The Effect of Polymer Blends on the Formulation of Sustained Release Ciprofloxacin Matrix Tablets

Background: The application of polymers to sustain drug release is increasingly becoming popular and the use of polymer blends provides an alternative method to developing new pharmaceutical raw materials.Objective: This work aims to study the effect of polymer blends of xanthan gum (X), hydroxypropylmethyl cellulose (HPMC) and Chrysophyllum albidum gum (CAG) on the mechanical properties and release rate of ciprofloxacin tablet.Method: Ciprofloxacin tablets prepared by direct compression was evaluated for weight uniformity, friability and hardness. The time taken for 50 % (T50) and 75 % (T75) drug release were obtained and the in vitro release data were fitted into drug kinetics models to determine the mechanism of drug release.Result: The tablets showed satisfactory mechanical strength. The rank order of tablet strength for the various blends is CAG-HPMC > CAG-X-HPMC > CAG-X. All the formulations with polymer blends had higher values of T50 and T75 than formulations containing single polymers. An increase in the proportion of CAG in formulation containing CAG-X (in ratio 2:1) resulted in almost a two- fold sustained drug release with T50 and T75 values of 4.4 and 7.1 hrs respectively. Generally, a blend of the three polymers resulted in a slower drug release. The proportion of polymers in the blend had no significant (p>0.05) effect on drug release rate in formulations containing the three polymers. Higuchi model was the most prominent model while the mechanism for drug release was super case II transport.Conclusion: This study highlights the potentials of polymer blends in the design and formulation of sustained release ciprofloxacin matrix tablets.Keywords: Polymer blend, Sustained release, Ciprofloxacin, Xanthan gum, Chrysophyllum albidum gu

In Vivo Anti-Inflammatory Assessment of a Topical Formulation Containing Ehretia Cymosa Extract Mediated-Silver Nanoparticles

Background: Silver nanoparticles (SNP) are the most preferred and most often used metallic nanoparticles in biomedical studies. However, there are only few studies on its application in topical drug delivery design. Objectives: This study was carried out to design topical ointments containing n-hexane and methanol Ehretia cymosa leaf extracts mediated-silver nanoparticles for the treatment of inflammation.Methods: Silver nitrate was reacted with n-hexane and methanol extracts of Ehretia cymosa leaf to synthesize SNP  used in the formulation of an ointment. The SNP was characterized by visual observation, UV–visible spectroscopy,  atomic absorption spectroscopy and FTIR spectroscopy. The physical characteristics of the ointment and  spreadability were evaluated. Inflammation was inflicted by carrageenan-induced paw acute edema  method in albino  rats. The linear paw circumference was measured hourly after application of the ointment.Results: There was colour change as the synthesis progresses. The absorption peak of n-hexane SNP (N-SNP) and methanol SNP (M-SNP) was 450 nm and 430 nm respectively. The ointments were easy to administer with satisfactory spreadability but difficult to wash off. Ointments containing SNP had significantly higher activity (p < 0.05) than the crude extract and ointments containing M-SNP had significantly higher activity (p < 0.05) than ointments containing N-SNP.Conclusion: The anti-inflammatory activity of ointment containing SNP synthesized with methanol extract is significantly higher compared to ointment formulations containing silver nanoparticle synthesized with n-hexane extract and the reference drug (diclofenac)