Application of the Gurnham Equation in Characterizing the Compressibility of Fonio and Sweet Potato Starches and their Paracetamol Tablet Formulations

Background: A number of empirical relationships have been proposed to describe the compaction of pharmaceutical materials, among them are the Heckel, Kawakita and Gurnham equations.Objective: To characterize the compressibility of fonio, sweet potato and corn starches and their paracetamol formulations using the Gurnham and Kawakita equations, and to determine the complementarity of these equations.Materials and Methods: Starches were extracted from fonio (Digitaria exilis) grains and sweet potato (Ipomea batatas) tubers and modified by acid hydrolysis for 96 h. Paracetamol formulations containing 2.5–10.0 %w/w starch binders were prepared by wet granulation. Packing and compaction properties of native and modified starches and their formulations were determined using tapping procedures. The data obtained was analyzed using the Gurnham and Kawakita equations.Results: The ranking for Gurnham compressibility, c, for the starches was sweet potato>corn>fonio, which was inversely related to the ranking for Kawakita maximum volume reduction, a and angle of internal flow, θ. There was no clear-cut pattern in the Gurnham compressibility of paracetamol formulation probably due to its multicomponent nature. There was correlation between c, a and θ for all the starches with the modified starches exhibiting higher compressibility than native starches. There appeared to be no correlation between c and Kawakita compressibility index, b.Conclusion: The Gurnham equation appeared useful in characterising compressibility in single component systems and could be used along with Kawakita functions, to gain a better understanding of the deformation of powdered materials under pressure.Keywords: Compressibility, Gurnham equation, Kawakita function, Fonio starch, sweet potato starc

Formulation and Antimicrobial Evaluation of Isopropyl Hand Sanitizer using Co-processed Excipients

Background: In response to the Ebola virus outbreak in West Africa in the year 2014, which caused the Ebola haemorrhagic fever, the WHO alcohol-based hand rub formulation was adopted in addition to regular hand washing to prevent the spread. However, other formulation factors rather than alcohol concentration alone can greatly influence the overall antimicrobial efficacy of hand disinfectants.Objective: To formulate an antimicrobial hand sanitizer using co-processed carriers.Methodology: Carbopol (F), HPMC (G) and co-processed forms of both polymers in batches- 1:1(A), 1:2(B), 1:4(C), 2:1(D) and 4:1(E) respectively were used. The polymers were characterized, and used as carriers in formulating hand sanitizers (A to G). The formulated hand sanitizers were evaluated for physical appearance, pH, clarity, viscosity, drying time and antimicrobial activity, in comparison to a commercially available hand sanitizer (CAHS).Results: Co-processing significantly (p0.05) improved both hydration capacity of carbopol and viscosity of HPMC. The physical appearance, pH and opacity were maintained throughout the study. All the formulations showed dilatant rheological behaviour while the CAHS exhibited plastic flow. The drying times for the formulated hand sanitizers were comparable to CAHS but longer than isopropyl alcohol implying prolonged action at application site. The antimicrobial activity of the formulations was of the rank order isopropyl alcohol>B>F>CAHS>D>E>C>G>A.Conclusion: Co-processing of excipients improved the pharmaceutical properties of the hand sanitizers with antimicrobial activity that was comparable to CAHS but lower than isopropyl alcohol. The hand sanitizer formulated with polymer batch B, demonstrated optimum antimicrobial and pharmaceutical properties and may be developed for commercial use. Keywords: Hand sanitizer formulation, Isopropyl alcohol, Carbopol, Hydroxypropyl MethylCellulose, Co-processed excipient