Oludele A. Itiola

Compressional Characteristics of Native and Pregelatinized Forms of Sorghum, Plantain, and Corn Starches and the Mechanical Properties of Their Tablets

ABSTRACT A study was made of the compressional characteristics of native and pregelatinized forms of sorghum, plantain, and corn starches and the mechanical properties of their tablets. Compressional characteristics were analyzed using density measurements and the Heckel and Kawakita plots. Pregelatinized starches exhibited more densification than native starches during die filling and at low pressures. The ranking for the mean yield pressure (Py) values for the starches was plantain<corn<sorghum, with the pregelatinized starches having lower values than the native starches. The ranking for the values of another pressure term, Pk—an inverse measure of plasticity, was corn<plantain<sorghum, but with the native starches having the lower values. For the tablets, the ranking for values of tensile strength (T) was corn>plantain>sorghum, while the ranking for the brittle fracture index (BFI) was plantain>corn>sorghum. Tablets made from pregelatinized starches had lower T and BFI values than those made from native starches. The results suggest that pregelatinization of the starches facilitated faster onset of plastic deformation but reduced the amount of plastic deformation which occurred during the compression process.

Evaluation of the Effects of Khaya Gum on the Mechanical and Release Properties of Paracetamol Tablets

Abstract A study of the comparative effects of khaya gum and two standard binding agents––polyvinylpyrrolidone (PVP) and gelatin––on crushing strength and friability, and the disintegration and dissolution characteristics of paracetamol tablets was made. The crushing strength-friability ratio (CSFR), the disintegration times, D, and the dissolution times t50, t90, and t1 (derived from the equation of Noyes and Whitney), all increased with an increase in binder concentration; however, the dissolution rate constants, k1 and k2, decreased. The ranking for the values of CSFR for tablets containing the different binders was PVP>gelatin>khaya gum. The ranking for D and the dissolution times was gelatin>khaya gum>PVP, whereas the ranking for the dissolution rate constants was PVP>khaya gum>gelatin. There were significant linear correlations between CSFR, D, t50, t90, and t1 for the tablets. There were also significant correlations between k1 and D, t50, t90, and t1, and between k2 and t90. The results suggest that khaya gum could be useful as an alternative binding agent to produce tablets with particular mechanical strength and drug release profiles.

Cultural categorization of febrile illnesses in correlation with herbal remedies used for treatment in Southwestern Nigeria

The ethnographic study was conducted in two communities in Oyo State in Southwestern Nigeria. The study sites consisted of a rural and an urban local government area located in the tropical rain forest zone of Nigeria. The study was designed to obtain information on febrile illnesses and herbal remedies for treatment with the aim of identifying potential antimalarial drugs. The study revealed that fever is a general term for describing illnesses associated with elevated body temperature. The indigenous Yoruba ethnic population has categorized fever based on symptoms and causes. The present communication is the result of focus group discussion and semi-structured questionnaire administered to traditional healers, herb sellers, elders and mothers. This was on types of fevers, symptoms and causes of febrile illnesses. The investigation also included use of traditional herbs in the prevention and treatment of the illnesses in the two communities.A total of 514 respondents were interviewed. This was made up of 266 (51.8%) from Atiba local government area (LGA), an urban centre while 248 (48.2%) respondents were interviewed from Itesiwaju LGA, a rural community. The LGAs are located in Oyo State of Nigeria. The respondents proffered 12 types of febrile illnesses in a multiple response answering system in Yoruba language. The most common ones (direct translation into English) were: yellow fever (39.1%), typhoid (34.8%), ordinary (28.8%), rainy season (20.8%) and headache (10.5%) fevers, respectively. Perceived causes of each of the febrile illnesses included stress, mosquito bites, unclean water, rains and over exposure to the sun. Methods of fever prevention were mainly with the use of herbal decoctions, powdered herbs, orthodox medications and maintenance of proper hygiene. Of a total of 112 different herbal remedies used in the treatment of the febrile illnesses compiled from the study, 25 recipes are presented. Recipes consisted of 2-7 ingredients. Oral decoctions (84%), oral powders (63%), use as soaps and creams (40%) in a multiple response system, were the most prevalent routes of administration of prepared herbs used in the treatment of the fevers. Boiling in water or alcohol was the most common method used in the preparation of the remedies. The four most frequently mentioned (multiple response system) plants in the Southwest ethnobotany for fevers were Azadirachta indica (87.5%), Mangifera indica (75.0%), Morinda lucida (68.8%) and Citrus medica (68.8%).

Formulation Effects on the Mechanical Properties of Metronidazole Tablets

Abstract— The individual and interaction effects of nature of binder (N), concentration of binder (C) and the physical form of the formulation (P) on the tensile strengths (T—a measure of the bond strength of tablets) and the brittle fracture index values (BFI—a measure of the lamination tendency of tablets) of metronidazole tablets have been studied using a 23 factorial experimental design in each case. Changing binder concentration from a ‘low’ to a ‘high’ level increased T and reduced the BFI of the tablets. Methylcellulose 20 exhibited stronger binding effect and greater ability to reduce the lamination tendency of the tablets than polyvinylpyrrolidone of molecular weight 44000. Granular formulations produced tablets with lower T values but also with lower BFI values than tablets produced from powdered formulations. The ranking of these individual effects on tensile strength was P > C > N while the ranking for the BFI was P > N > C. For the interaction effects, the ranking for tensile strength was P—N ≫ N—C > P—C while the ranking for the BFI was N—C ≫ P—C > P—N.

Antimalarial Ethnobotany: In Vitro. Antiplasmodial Activity of Seven Plants Identified in the Nigerian Middle Belt

Abstract Seven methanol extracts of seven plants from seven plant families were screened for antimalarial properties. The plants were identified and selected from Gboko and Kastina-Ala local government areas in the Tivland ethnobotany in the Middle Belt Zone of Nigeria. Methanol plant extracts were evaluated for in vitro. antimalarial properties using the lactate dehydrogenase technique, with a multiresistant strain of Plasmodium falciparum. K1. Quantification of activity was by estimation of the concentration of extracts that inhibited 50% growth of parasite (IC50) in µg/ml. Of the seven plants screened, Erythrina senegalensis. DC (Leguminosae), Pericopsis elata. Harms (Papilionaceae), and Bridelia micrantha. Benth (Fabaceae) had IC50 values of 99.7, 124.8, and 158.7 µg/ml, respectively. Nauclea latifolia. SM (Rubiaceae) extract exhibited the least activity in the assay with an IC50 value of 478.9 µg/ml.

Characterization of Khaya Gum as a Binder in a Paracetamol Tablet Formulation

ABSTRACT The influence of khaya gum, a binding agent obtained from Khaya grandifolia (Meliaceae family), on the bulk, compressional, and tabletting characteristics of a paracetamol tablet formulation was studied in comparison with the effects of two standard binders: polyvinylpyrrolidone (PVP; molecular weight 40,000) and gelatin. The relative ability of khaya gum to destroy any residual microbial contamination in the binder or in the formulation during tabletting was also studied using Bacillus subtilis spores as a model. Formulations containing khaya gum exhibited more densification than formulations containing PVP and gelatin during die filling, but less densification due to rearrangement at low pressures. The mean yield pressure of the formulation particles obtained from Heckel plots, and another pressure term, also inversely related to plasticity, obtained from Kawakita plots, showed dependence on the nature and concentration of the binder, with formulations containing khaya gum exhibiting the lowest and highest values respectively. The values of the pressure terms suggest that the yield pressure relates to the onset of plastic deformation during compression, while the Kawakita pressure relates to the total amount of plastic deformation occurring during the compression process. Tablets made from formulations containing khaya gum had the lowest tensile strength values but also the lowest tendency to laminate or cap, as indicated by their lowest brittleness. All the tablets had friability values <1% at higher concentrations of the three binders. In addition, khaya gum demonstrated a comparable ability to destroy microorganisms in the formulation during tabletting as the two binders. The characterization of the formulations suggests that khaya gum can be developed into a commercial binding agent for particular tablets.

Effects of plantain and corn starches on the mechanical and disintegration properties of paracetamol tablets

The effects of plantain starch obtained from the unripe fruit of the plantMusa paradisiaca L. (Musaceae) on the mechanical and disintegration properties of paracetamol tablets have been investigated in comparison with the effects of corn starch BP using a 23 factorial experimental design. The individual and combined effects of nature of starch binder (N), concentration of starch binder (C), and the relative density of tablet (RD) on the tensile strength (TS), brittle fracture index (BFI), and disintegration time (DT) of the tablets were investigated. The ranking of the individual effects on TS was RD>C≫N, on BFI was C≫RD>N and on DT was N>C>RD. The ranking for the interaction effects on TS and DT was N-C≫N-RD>C-RD, while that on BFI was N-C≫C-RD>N-RD. Changing nature of starch from a “low” (plantain starch) to a “high” (corn starch) level, increasing the concentration of starch binding agent from 2.5% to 10.0% wt/wt, and increasing relative density of the tablet from 0.80 to 0.90, led to increase in the values of TS and DT, but a decrease in BFI. Thus, tablets containing plantain starch had lower tensile strength and disintegration time values than those containing corn starch, but showed better ability to reduce the lamination and capping tendency in paracetamol tablet formulation. The interaction between N and C was significantly (P<.001) higher than those between N and RD and between C and RD. There is therefore the need to carefully choose the nature (N) and concentration (C) of starch used as binding agent in tablet formulations to obtain tablets of desired bond strength and disintegration properties. Furthermore, plantain starch could be useful as an alternative binding agent to cornstarch, especially where faster disintegration is required and the problems of lamination and capping are of particular concern.

Effects of Pigeon Pea and Plantain Starches on the Compressional, Mechanical, and Disintegration Properties of Paracetamol Tablets

ABSTRACT A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T-a measure of bond strength) and brittle fracture index (BFI-a measure of lamination tendency). The ranking for the mean yield pressure, Py, for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for Pk, an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.

Individual and interacting effects of formulation variables on the tensile strength and microbial survival in diclofenac tablets

A work has been done to study the individual and interacting effects of formulation variables, using a 23 fractional factorial design. The effects of five variables, namely, relative density of tablets, nature and concentration of binder, compression process, and compression speed on the tensile strength and percent survival of Bacillus subtilis spores in Diclofenac tablet formulations were determined. The effects of these variables were studied both singly and when they interact with each other in two fractional designs (Woolfall, 1964). The first fraction comprised of Nature (N) and Concentration (C) of binder, and Relative density of tablets (D) while in the second fraction, Compression speed (S), Compression process (P) and Relative density of tablets (D) were studied. In the first fraction, concentration of binder had the highest effect on tensile strength with the ranking C > D > N for both DCS (formulation containing Corn starch) and DDCP (formulation containing DCP), and C > N > D for DL (formulation containing Lactose). On the percent survival of Bacillus subtilis, relative density of tablets showed the highest effect with the ranking D > C > N for both DCS and DL, and D > N > C for DDCP. In the second fraction, compression speed generally had a great effect on both tensile strength and percent survival in all the formulations. The results of interactions among the variables showed the highest effect on tensile strength from interaction between concentration of binder and relative density of tablets (C-D) while interaction between compression speed and relative density of tablets (S-D) had the highest effect on percent survival in all the formulations. A fractional factorial design proved suitable in determining the magnitude of both the individual and interacting effects of the variables. The study showed that each of these variables has to be properly considered in producing tablets of satisfactory strength and reduced microbial survival.

Comparative Evaluation of the Binding Properties of Two Species of Khaya Gum Polymer in a Paracetamol Tablet Formulation

A study was made of the comparative effects of polymers obtained from two species of khaya tree – Khaya senegalensis and Khaya grandifoliola – as binding agents in a paracetamol tablet formulation. The mechanical properties of the tablets were assessed using the tensile strength (T), brittle fracture index (BFI) and friability (F) of the tablets while the drug release properties of the tablets were assessed using disintegration and dissolution times. The tensile strength, disintegration and the dissolution times of tablets increased with the increase in binder concentration while F and BFI decreased. K. senegalensis gum produced tablets with stronger mechanical properties with less tendency to laminate, and longer disintegration and dissolution times than K. grandifoliola gum. The results suggest that the polymer gum from K. senegalensis will be more appropriate as a binding agent than the gum from K. grandifoliola when higher mechanical strength and slower release profiles of tablets are desired.