Open Access Original Research Article

Toxicity Studies of the Extracts of Parkia biglobosa Stem Bark in Rats

M. I. Builders, C. O. Isichie, J. C. Aguiyi

Journal of Pharmaceutical Research International, Page 1-16
DOI: 10.9734/BJPR/2012/906

Extracts of Parkia biglobosa stem bark is used in Nigerian traditional medicine (NTM) to treat malaria, diarrhea and pains. To establish the toxicity profile of the medicine such parameters as the lethal dose (LD50) as well as effects on body functions and organs were evaluated in albino Wistar rats. The bioactive constituents of the water and methanol extracts were also evaluated as a link to toxicity. The LD50 was greater than 5000mg/kg per oral (p.o) for both extracts. No significant (P<0.05) changes in body weights and vital organs of treated animals. However, at 5000mg/kg of water extract, a significant increase in relative weight of the kidneys and hyper -cholesterolemic effects were observed. The extract also elicited significant increase in blood glucose level. The kidneys and livers of animals treated with P. biglobosa water extract for 14 days revealed histopathological evidence of pathological lesions. The methanol extract did not show any changes in the levels of hepatic and hematological parameters, histopathological evidence of pathological lesions, and serum level of urea, uric acid, bilirubin, creatinine and total protein concentrations. Treatment elicited hypo -cholesterolemic effects and significant reduction in blood glucose level occurred in all the groups. The phytochemical screening revealed the presence of tannins, flavonoids, saponins, terpenes, cardiac glycosides, phenols and reducing sugars in the methanol extract, the water extract showed the presence of similar constituents with the absence of flavonoids and cardiac glycosides. This study has shown the toxicity characteristics of the methanol and water extracts of the stem bark P. biglobosa in short time treatment with the extracts.

Open Access Original Research Article

Formulation and In-Vivo Study of Diltiazem Hydrochloride Tablets Prepared Using Interpolymer Complexes

Abd EL – Gawad H. Abd EL – Gawad, Esmail M. Ramadan, Osama A. Soliman, Rehab M. Yusif

Journal of Pharmaceutical Research International, Page 17-40
DOI: 10.9734/BJPR/2012/1049

Aim: To investigate interpolymer complexes (IPCs) formation between carbopol and cationic polymers such as chitosan and Eudragit E for oral controlled drug delivery systems.
Methodology: The prepared IPCs were investigated using Fourier transform infra-red spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Chitosan-carbopol and Eudragit E-carbopol IPCs loaded with diltiazem hydrochloride (DTZ HCl) with different drug:polymer ratios were also prepared. Diltiazem hydrochloride tablets were prepared using polymers alone, physical mixtures of chitosan or Eudragit E with carbopol and the corresponding drug loaded IPCs. In-vitro release studies were carried out in two dissolution media; 0.1 NHCl of pH 1.2 and phosphate buffer of pH 7.4.
Results: The dissolution rate of DTZ HCl from the prepared tablets were found to be dependant on the interaction between chitosan or Eudragit E with carbopol in the physical mixture, drug:polymer ratio and pH of the dissolution medium. Tablets prepared using chitosan – carbopol IPC, Eudragit E – carbopol IPC, and Eudragit E – carbopol physical mixture of drug:polymer ratio 1:5 were selected for the in-vivo study using rabbits. The results showed a lower peak plasma concentration and marked prolonged release effect of tablets containing Eudragit E – carbopol IPC and the corresponding physical mixture compared to that of commercial Altiazem tablets.
Conclusion: Tablets containing Eudragit E – carbopol or chitosan – carbopol physical mixtures showed prolonged drug release compared to that containing the corresponding IPCs, Furthermore, Eudragit E- carbopol matrix tablets showed slower drug release than that of chitosan – carbopol.

Open Access Original Research Article

Effect of Acarbose on the Bioavailability and Pharmacokinetics of Metronidazole in Healthy and Diabetic Subjects

Saad A. Hussain, Haydar A. H. Kurji, Mowafaq M. Ghareeb, Munaf H. Abdulrazzaq

Journal of Pharmaceutical Research International, Page 41-49
DOI: 10.9734/BJPR/2012/1109

Although drug interactions with Acarbose are uncommon, there is a possibility for interference with the pharmacokinetic behaviors of concomitantly administered drugs. The present study was designed to evaluate the possible drug interactions between Acarbose and orally administered MTZ. Twelve healthy volunteers and twelve diabetic patients were enrolled in a randomized controlled crossover study. The effect of Acarbose (single 100mg dose) on the pharmacokinetics of MTZ was evaluated, while the effect of multiple doses was evaluated only in diabetic patients. In both groups, 5ml blood samples were collected into plane tubes at 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 6.0, 8.0, 12.0, 24.0 and 48.0 hrs; serum levels of MTZ were evaluated using HPLC technique. The results showed that diabetes mellitus significantly altered the pharmacokinetic parameters of orally administered MTZ compared to healthy subjects. Moreover, both single and multiple doses of Acarbose significantly changed the pharmacokinetic parameters of MTZ when used concomitantly. The pharmacokinetics of orally administered MTZ was significantly affected by both diabetes mellitus and concomitant use of single or multiple doses of Acarbose.

Open Access Original Research Article

Intrinsic and Functional Properties of a Gelling Gum from Dioclea reflexa: A Potential Pharmaceutical Excipient

Philip F. Builders, Chukwuemeka C. Mbah, Anthony A. Attama

Journal of Pharmaceutical Research International, Page 50-68
DOI: 10.9734/BJPR/2012/971

Aims: Dioclea reflexa Hook F., is a woody vine widely distributed within tropical Africa and South America, in Nigeria flour prepared from the seeds is used as a soup thickener. The objectives of this study were to extract and modify the native gum from the seeds of D. reflexa, and evaluate their physicochemical and functional properties as a potential pharmaceutical excipient.
Place and Duration of Study: Department of Pharmaceutical Technology and Raw Materials Development, National Institute for Pharmaceutical Research and Development, Abuja, Nigeria. Between January 2009 and October 2010. And Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Nigeria. Between June 2010 and October 2011.
Methodology: Native D. reflexa gum (DR-gum) was extracted from the seeds of D. reflexa and modified by ionotropic gelation in calcium chloride solution. The gum’s gel clarity and swelling in buffer solutions of different pH (4, 7, and 9.2), as well as the moisture sorption characteristics at different relative humidity (RH) were determined in relation to guar gum (G-gum). Also, the Fourier transform infrared (FT-IR) and Differential scanning calorimetry (DSC) analysis as well as the powders’ flow properties were evaluated.
Results: DR-gum, XDR-gum and G-gum are typical hydrogels showing considerable responsiveness in swelling and gel clarity to changes in pH. The DSC thermographs of DR-gum and G-gum were similarly characterized by a glass transition and a cold crystallization transitions peaks as compared to the glass transition and melting transition peak of XDR-gum. The moisture sorption profile indicated that DR-gum and G-gum are moderately hygroscopic while XDR-gum is slightly hydroscopic. The FT-IR of the gums showed the basic differences in the functional groups of the respective polymer chain network. The bulk particles of the three gums showed comparative good flow.
Conclusion: The basic similarities and differences in the physicochemical and functional properties of DR-gum and XDR-gum, and G-gum indicate their potential as a pharmaceutical excipient.