An investigative study of Diffusion of Commercial Aspirin (Acetylsalicylic acid) in Sodium Hydroxide Solution at 25oC

Diffusion is a macroscopic motion of components of a system that arises from concentration difference. Reaction diffusion is widely used to model developmental process. This project considers effective mechanism leading to effective diffusion coefficient. A mathematical formalism for transforming local transport law into diffusive terms is developed. The diffusion coefficient of drug aspirin was studied in basic NaOH of concentration range 0.01 to 0.1M at 25oC. The rate of diffusion was monitored by observing the boundary conditions of the indicator between the drug and solution. In the study five (5) aspirin tablets collected from a local pharmacy in Eldoret town were used for the study. From the profile it was observed that as the time progressed the boundary increased fast for non-coated tablets compared to the coated ones. All the aspirin were found to give values according to underlying mechanism. For the drug A (600mg) of aspirin the best value of diffusion coefficient of 1.69 x 10-4 cm2 sec-1 was observed while the values for coated drug E with 75 mg aspirin was found to be slightly lower. Fickian mechanism is believed to be the consequence of drug molecule small size.  First of all fractional drug uptake is linear and independent of the sample of thickness when In [NaOH] is plotted against square distance. A graph of x2 against In [NaOH] was plotted which was used to calculate the diffusion coefficient. The experimental values of diffusion coefficient D were within the experimental error to those of (4Dt)-1. The study also adopted a descriptive case study; it was conducted at Kimumu municipality, Eldoret town. The target population consisted of 25 respondents. Data was collected using self-administered questionnaires and interview schedules, coded and analysed using SPSS version 16.0. Systematic quantitative review data was analysed using means and frequency tables and percentages while qualitative data was analyzed using inferential statistics chi-square. Data was presented using table, pie charts and graphs.  The study found that most of the individuals preferred drug B. Keywords:  Diffusion, Aspirin, Acetylsalicylic acid, Diffusion Coefficient, Sodium Hydroxide, Fickian Mechanism, Systematic Revie

Diffusion of Aspirin (ASA) Based Drugs in Sodium Hydroxide Solution at Ambient Temperature.

Diffusion is a macroscopic motion of components of a system that arises from concentration difference and plays a vital role in drug migration in the body governed by Fickian diffusion laws. This project considers effective mechanism leading to effective diffusion coefficient. The diffusion coefficient of aspirin based drugs was studied in basic NaOH of concentration range 0.01M to 0.1M and a relatively more concentrated set ranging from 0.1M to 1.0M were studied at 25oC. The study looks into the rate of diffusion of coated and non-coated aspirin drugs in aqueous NaOH solution designated different letter heads A, B, C, D, and E. The objective of this work was to determine the diffusion coefficients of aspirin drugs at different concentrations range at 25oC and to compare with those calculated from limiting ionic conductance at infinite dilution. The rate of diffusion was monitored by observing the boundary conditions of the indicator between the drug and solution. The problem statement is that there are various aspirin based drugs in the market and all have different amount of aspirin in them. The research sought to find out the rate of diffusion of the drugs and conclude if at all their values relate to their masses as per the diffusion law. In the study five (5) aspirin tablets collected from a local pharmacy in Eldoret town were used for the study. From the profile it was observed that as the time progressed the boundary increased fast for noncoated tablets compared to the coated ones. The boundary heights (x) at a time t and concentration are also recorded. The moving boundary method coefficients ranged from 2.780 x 10-6 cm2 sec-1 to 6.995 x 10-6 cm2 sec- 1, 2.196 x 10-6 cm2 sec-1 to 6.092 x 10-6 cm2 sec-1, 2.138 x 10-7 cm2 sec-1 to 6.576 x 10-7 cm2 sec-1 , 3.241 x 10-10 cm2 sec-1 to 1.617 x 10-10 cm2 sec-1 and 1.378 x 10-10 cm2 sec-1 to 2.172x 10-10 cm2 sec-1 for drugs aspirin A , B, C. D and E respectively. All the aspirin were found to give values according to Fickian mechanism. For the drug A (600mg) of aspirin the best value of diffusion coefficient of 6.995 x 10-6 cm2 sec-1 at concentrated solution and 2.780 x 10-6 cm2 sec-1 was observed at dilute range solutions while the values for coated drug E with 75 mg aspirin was found to be slightly lower. The fractional drug uptake is linear and independent of the sample of thickness when distance is plotted against time. A graph of x2 against time was plotted which was used to calculate the diffusion coefficient. The experimental values of diffusion coefficient Do were in close agreement with the expected value from infinite dilution which was a general estimation of diffusion coefficients. Quantitative data was analysed using analysis of variance and chi-square statistical. Data was presented using table and graphs. The study found that the aspirin drug with the highest diffusion coefficient is drug A. In addition, conductometric technique was recommended to give more accurate results and similar method should be constituted with the use of other techniques such as TLC and spectrophotometric method for comparison purposes with the free diffusion and it is important for manufacturers to revalidate steps in the production process, for any critical control point in the production process leads to hydrolysis of aspirin. Key words: Diffusion, Aspirin, Acetylsalicylic acid, Diffusion Coefficient, Sodium Hydroxide, Fickia

Two new structures of 5-nitrouracil

The structure of monoclinic anhydrous 5-nitrouracil, C4H3N304, and of the solvate 5-nitrouracil dimethyl sulfoxide, C4H3N304.C2H6OS, are presented and compared with the previously known structures of the orthorhombic anhydrous form and the monohydrate

5,7,7,12,14,14-Hexamethyl-4,8-diaza-1,11-diazoniocyclotetradeca-4,11-diene diiodide dihydrate

The asymmetric unit of the title compound, C16H34N42+ center dot- 2I(-) center dot 2H(2)O, contains one half-cation, one iodide anion and one water molecule. The cation has crystallographically imposed centrosymmetric symmetry. Despite some differences in the unit-cell dimensions, packing analysis on a cluster of 15 cations and a comparison of the hydrogen bonding suggests that this compound is isostructural with its bromide analogue. Intermolecular hydrogen bonding forms eight-membered [H-OH center dot center dot center dot I](2) and [H-N-H center dot center dot center dot I](2) rings and creates a sheet structure

Cephalexin: a channel hydrate

The antibiotic cephalexin [systematic name: d-7-(2-amino-2-phenyl­acet­amido)-3-methyl-8-oxo-5-thia-1-aza­bi­cyclo­[4.2.0]oct-2-ene-2-carboxyl­ic acid] forms a range of isomorphic solvates, with the maximum hydration state of two water mol­ecules formed only at high relative humidities. The water content of the structure reported here (C16H17N3O4S·1.9H2O) falls just short of this configuration, having three independent cephalexin mol­ecules, one of which is disordered, and 5.72 observed water mol­ecules in the asymmetric unit. The facile nature of the cephalexin solvation/desolvation process is found to be facilitated by a complex channel structure, which allows free movement of solvent in the crystallographic a and b directions

Assessing the productivity of indigenous chickens in an extensive management system in southern Nyanza, Kenya

Edward Okoth is ILRI authorThe present study was conducted to assess the performance of indigenous chickens under extensive system in southern Nyanza, Kenya. The study was carried out in two phases in Komolorume and Kawere villages in Rongo and Rachuonyo districts, respectively. The first phase was a cross-sectional study in 81 farms selected by cluster sampling to get the overview of the indigenous chicken production. A four-month prospective longitudinal study in 60 farms randomly selected from the previous 81 farms followed. Mean flock sizes per household were 20 and 18 birds in Komolorume and Kawere, respectively. Overall mean flock size was 19 birds ranging from 1to 64. The mean clutch size, egg weight and hatchability were 12 eggs, 48 g and 81% respectively in Komolorume and 10 eggs, 45 g and 70%, respectively, in Kawere. The chick survival rates to the age of eight weeks were 13% and 10% in Komolorume and Kawere, respectively. Mean live weights for cocks and hens were 2096 g and 1599 g in Komolorume and 2071 g and 1482 g in Kawere, respectively. The mean household cock to hen ratio was 2:5 and 2:4 for Komolorume and Kawere, respectively. The mean chick to grower to adult ratio per household was 8: 6:6 in Komolorume and 8:4:6 in Kawere. Clutch sizes and hatchability rates were significantly higher in Komolorume village (P < 0.5). The productivity of the indigenous chickens was shown to be low compared to that of the improved chickens in other parts of the world

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort