Comparative analysis of eight brands of sulfadoxine-pyrimethamine tablets

Purpose: The aim of the present study is to investigate the physicochemical equivalence of eight brands of tablets containing sulfadoxine-pyrimethamine (antimalarial drug combination) sourced from different retail Pharmacy outlets in the Nigerian market. Method: The quality and physicochemical equivalence of eight different brands of sulfadoxine-pyrimethamine combination tablets were assessed. The assessment included the evaluation of uniformity of weight, friability, crushing strength, disintegration and dissolution tests as well as chemical assay of the tablets. Results: All the eight brands of the tablets passed the British Pharmacopoeia (BP) standards for uniformity of weight, disintegration and crushing strength. Three of the eight brands failed the friability test. One of the brands did not comply with the standard assay of content of active ingredients while another brand did not comply with the USP specifications for dissolution test for sulfadoxine-pyrimethamine tablets. There were no significant differences in the amounts of pyrimethamine and sulfadoxine released from the different brands (P>0.05). Conclusion: Only three brands (registered by NAFDAC) out of the eight brands of sulfadoxine-pyrimethamine tablets that were analysed passed all the BP quality specifications and were physically and chemically equivalent. This study highlights the need for constant market monitoring of new products to ascertain their equivalency to the innovator product. Keywords: Chemical equivalence, comparative study, pyrimethamine-sulfadoxine tablets Tropical Journal of Pharmaceutical Research 2003; 2(1): 161-16

Solid state characterization and rheological properties of native and modified Bambara groundnut (Vigna subterranean) starches

This study was designed to determine the suitability of native, pregelatinized and carboxymethylated Vigna subterranean (Bambara nut) starches for pharmaceutical applications, through their characterization by means of physicochemical, rheological, thermal, morphological and instrumental spectroscopic methods. The native starch was extracted from Bambara nut, after which it was used to prepare both pregelatinized and carboxymethylated forms. Microscopy revealed increased in granular size on modification. Both pregelatinized and carboxymethylated Bambara starches had better flow properties and swellability compared to the native starch. Native Bambara starch had greater tendency to retrogradation, was more sensitive to heat and heat change, these were alleviated by both pregelatinization and carboxymethylation. DSC confirmed that carboxymethylated Bambara starch was the most thermally stable starch. Presence of functional groups and crystallinity were established by FTIR and XRD, respectively. Native and modified Bambara starches can be used as locally and readily available alternative excipients in pharmaceutical formulations

The effect of thermal and chemical modifications of excipients on the compressional properties of paracetamol tablet formulations including maize, cassava and sweet potato starches as filler-binders

The effects of thermal and chemical modifications on the properties of directly compressed paracetamol tablets containing cassava and sweet potato starches were compared with official maize starch. Fresh tubers of the cassava plant, Manihot esculenta Crantz (family Euphorbiaceae) and the sweet potato plant Ipomoea batatas L. Lam (family Convolvulaceae) were obtained and the acetylated and pregelatinized forms of these were prepared using Maize Starch BP as the standard. Paracetamol tablet formulations (500mg) were prepared by direct compression including the starches at various amounts. The compressional properties of the tablets were evaluated using the Heckel, Kawakita and Gurnham equations. Modifications of the starches decreased the Pk (an inverse measure of plasticity) values in the paracetamol formulations at low starch concentrations (10.0% to 25.0%), indicating an increase in the total amount of plastic flow. The Pk values increased at higher starch concentrations (> 50.0%). Tablets containing maize starch showed higher c values when using the Gurnham equation suggesting greater densification. The thermal and chemical modification of the experimental starches improved the compressional properties of the directly compressed paracetamol tablet suggesting that they could be developed for use as pharmaceutical excipients

Consensus molecular subtype differences linking colon adenocarcinoma and obesity revealed by a cohort transcriptomic analysis

Colorectal cancer (CRC) is the third-leading cause of cancer-related deaths in the United States and worldwide. Obesity—a worldwide public health concern—is a known risk factor for cancer including CRC. However, the mechanisms underlying the link between CRC and obesity have yet to be fully elucidated in part because of the molecular heterogeneity of CRC. We hypothesized that obesity modulates CRC in a consensus molecular subtype (CMS)-dependent manner. RNA-seq data and associated tumor and patient characteristics including body weight and height data for 232 patients were obtained from The Cancer Genomic Atlas–Colon Adenocarcinoma (TCGA-COAD) database. Tumor samples were classified into the four CMSs with the CMScaller R package; body mass index (BMI) was calculated and categorized as normal, overweight, and obese. We observed a significant difference in CMS categorization between BMI categories. Differentially expressed genes (DEGs) between obese and overweight samples and normal samples differed across the CMSs, and associated prognostic analyses indicated that the DEGs had differing associations on survival. Using Gene Set Enrichment Analysis, we found differences in Hallmark gene set enrichment between obese and overweight samples and normal samples across the CMSs. We constructed Protein-Protein Interaction networks and observed differences in obesity-regulated hub genes for each CMS. Finally, we analyzed and found differences in predicted drug sensitivity between obese and overweight samples and normal samples across the CMSs. Our findings support that obesity impacts the CRC tumor transcriptome in a CMS-specific manner. The possible associations reported here are preliminary and will require validation using in vitro and animal models to examine the CMS-dependence of the genes and pathways. Once validated the obesity-linked genes and pathways may represent new therapeutic targets to treat colon cancer in a CMS-dependent manner

APOE E4 is associated with impaired self-declared cognition but not disease risk or age of onset in Nigerians with Parkinson's disease

The relationship between APOE polymorphisms and Parkinson's disease (PD) in black Africans has not been previously investigated. We evaluated the association between APOE polymorphic variability and self-declared cognition in 1100 Nigerians with PD and 1097 age-matched healthy controls. Cognition in PD was assessed using the single item cognition question (item 1.1) of the MDS-UPDRS. APOE genotype and allele frequencies did not differ between PD and controls (p > 0.05). No allelic or genotypic association was observed between APOE and age at onset of PD. In PD, APOE ε4/ε4 conferred a two-fold risk of cognitive impairment compared to one or no ε4 (HR: 2.09 (95% CI: 1.13-3.89; p = 0.02)), while APOE ε2 was associated with modest protection against cognitive impairment (HR: 0.41 (95% CI 0.19-0.99, p = 0.02)). Of 773 PD with motor phenotype and APOE characterized, tremor-dominant (TD) phenotype predominated significantly in ε2 carriers (87/135, 64.4%) compared to 22.2% in persons with postural instability/gait difficulty (PIGD) (30/135) and 13.3% in indeterminate (ID) (18/135, 13.3%) (p = 0.037). Although the frequency of the TD phenotype was highest in homozygous ε2 carriers (85.7%), the distribution of motor phenotypes across the six genotypes did not differ significantly (p = 0.18). Altogether, our findings support previous studies in other ethnicities, implying a role for APOE ε4 and ε2 as risk and protective factors, respectively, for cognitive impairment in PD

Opinion Article - Effects of interacting variables on the release properties of chloroquine and aminophylline suppositories

Purpose: The individual and interaction effects of formulation variables on the release of suppositories were investigated using a 23 factorial experimental design. The variables studied were nature of base (B), type of drug (D), and presence of surfactant (S). Method: Suppositories were formulated with theobroma oil and Witepsol H15 as bases at 'low' and 'high' levels respectively. Chloroquine and aminophylline, both water-soluble drugs, were incorporated as active constituents at 'low' and 'high'levels respectively while Tween 80 was incorporated as surfactant in some of the formulations. Disintegration time and time taken for 50% of the drug to dissolve were used as assessment parameters. Results: The inclusion of surfactant in the suppository formulation proved to be the most significant variable in the formulation. The ranking for the individual coefficient values for the formulations was S> >B>D for disintegration time DT and S > > >D >B for the dissolution parameter t50. While the ranking for the interaction effects was B-D>B-S>S-D on DT and on t50 S-D>B-S>B-D. Conclusion: The results suggest that in formulating water-soluble drugs such as chloroquine and aminophylline as suppositories in a hydrophobic base, the presence of a surfactant is the most influential variable

Solid state characterization and rheological properties of native and modified Bambara groundnut (Vigna subterranean) starches

This study was designed to determine the suitability of native, pregelatinized and carboxymethylated Vigna subterranean (Bambara nut) starches for pharmaceutical applications, through their characterization by means of physicochemical, rheological, thermal, morphological and instrumental spectroscopic methods. The native starch was extracted from Bambara nut, after which it was used to prepare both pregelatinized and carboxymethylated forms. Microscopy revealed increased in granular size on modification. Both pregelatinized and carboxymethylated Bambara starches had better flow properties and swellability compared to the native starch. Native Bambara starch had greater tendency to retrogradation, was more sensitive to heat and heat change, these were alleviated by both pregelatinization and carboxymethylation. DSC confirmed that carboxymethylated Bambara starch was the most thermally stable starch. Presence of functional groups and crystallinity were established by FTIR and XRD, respectively. Native and modified Bambara starches can be used as locally and readily available alternative excipients in pharmaceutical formulations

Solid state characterization and rheological properties of native and modified Bambara groundnut (Vigna subterranean) starches

This study was designed to determine the suitability of native, pregelatinized and carboxymethylated Vigna subterranean (Bambara nut) starches for pharmaceutical applications, through their characterization by means of physicochemical, rheological, thermal, morphological and instrumental spectroscopic methods. The native starch was extracted from Bambara nut, after which it was used to prepare both pregelatinized and carboxymethylated forms. Microscopy revealed increased in granular size on modification. Both pregelatinized and carboxymethylated Bambara starches had better flow properties and swellability compared to the native starch. Native Bambara starch had greater tendency to retrogradation, was more sensitive to heat and heat change, these were alleviated by both pregelatinization and carboxymethylation. DSC confirmed that carboxymethylated Bambara starch was the most thermally stable starch. Presence of functional groups and crystallinity were established by FTIR and XRD, respectively. Native and modified Bambara starches can be used as locally and readily available alternative excipients in pharmaceutical formulations