ABSTRACT
Efavirenz, a widely prescribed anti retroviral drug belongs to class IΙ under BCS and exhibit low and variable oral bioavailability due to its poor aqueous solubility. Its oral absorption is dissolution rate limited and it requires enhancement in the solubility and dissolution rate for increasing its oral bioavailability. The objective of the study is to evaluate the feasibility of formulating efavirenz –βCD– PVP K30/SLS inclusion complexes into tablets and to evaluate the effects of βCD, PVP K30and SLS on the dissolution rate and dissolution efficiency of efavirenz tablets in a 23 factorial study. A comparative evaluation of wet granulation and direct compression methods was made for the preparation of tablets employing drug – βCD – PVP K30/ SLS inclusion complexes. Drug – βCD- PVP K30/ SLS inclusion complexes were prepared by kneading method. Tablets each containing 50 mg of efavirenz were prepared by wet granulation and direct compression methods employing various βCD complexes as per 23 factorial design and the tablets were evaluated for dissolution rate and other physical properties. Efavirenz tablets formulated employing dug – βCD – PVP K30/ SLS inclusion complexes and prepared by direct compression method disintegrated rapidly when compared to those made by wet granulation method. Efavirenz dissolution was rapid and higher from the tablets formulated employing drug- βCD- PVP K30 /or SLS inclusion complexes when compared to the tablets containing efavirenz alone in both wet granulation and direct compression methods. The individual as well as combined effects of the three factors involved i.e., βCD ( factor A), PVP K30( factor B) and SLS( factor C) were highly significant (P< 0.01) in enhancing the dissolution rate (K1) and dissolution efficiency (DE 30) of efavirenz in both wet granulation and direct compression methods. Among the three factors βCD (factor A) gave highest enhancement in the dissolution rate (K1) and dissolution efficiency (DE 30) of efavirenz tablets in both wet granulation and direct compression methods. SLS (factor C) alone gave low dissolution rate in both wet granulation and direct compression methods .Overall direct compression method gave higher dissolution rates (K1) and dissolution efficiency (DE 30) values than the wet granulation method in all the cases. Combination of βCD with either PVP K30 or SLS or both gave a significantly higher dissolution rate (K1) of efavirenz in both wet granulation and direct compression methods. Hence a combination of βCD with either PVP K30 or SLS or both is recommended to enhance the dissolution rate and efficiency of efavirenz tablets.
ABSTRACT
The objective of the study is to evaluate the individual main effects and combined (or interaction) effects of Hydroxy propyl β cyclodextrin (HPβCD), poly vinyl pyrrolidone (PVP K30) and sodium lauryl sulphate (SLS) on the solubility and dissolution rate of efavirenz in a series of 23 factorial experiments. The solubility of efavirenz in eight selected fluids containing HPβCD, PVP K30 and SLS as per 23 factorial study was determined. The solubility of efavirenz was markedly enhanced by HPβCD (2.95 fold), PVP K30 (2.49 fold) and SLS (226.96 fold) individually. Combination of HPβCD with PVP K30 and SLS gave a markedly higher enhancement in the solubility of efavirenz than is possible with them individually. HPβCD in combination with PVP K30 and SLS gave respectively 4.05 and 387.63 fold increase in the solubility of efavirenz. Solid inclusion complexes of efavirenz - HPβCD were prepared with and without PVP K30 and SLS as per 23- factorial design by kneading method and were evaluated. ANOVA indicated that the individual main effects of HPβCD, PVP K30 and SLS and their combined effects in enhancing the solubility and dissolution rate (K1 )and dissolution efficiency (DE30 ) were highly significant (P < 0.01).HPβCD alone gave a 16.74 fold increase in the dissolution rate of efavirenz. HPβCD in combination with PVP K30 and SLS gave respectively 19.98 and 25.13 fold increase in the dissolution rate of efavirenz. HPβCD in combination with both PVP K30 and SLS gave highest enhancement (41.61 fold) in the dissolution rate of efavirenz. Combination of HPβCD with PVP K30 and SLS has markedly enhanced the solubility as well as dissolution rate of efavirenz than is possible with them individually. Hence a combination of HPβCD with PVP K30 and / or SLS is recommended to enhance the solubility and dissolution rate of efavirenz, a BCS class II drug.
ABSTRACT
Anti-VP7 bluetongue virus (BTV) antibodies were detected in sera of ruminant livestock using competitive enzyme linked immunosorbent assay (c-ELISA). The per cent positivity for BTV antibodies recorded in sheep was 34.61% in Haryana, 7.14% in Himachal Pradesh and 28.88% in Punjab. Goat showed 64% positivity in Haryana, 67.34% in Himachal Pradesh and 88.33% in Rajasthan whereas cattle showed 67.44% positivity in Haryana, 52.17% in Punjab and 59.15% in Rajasthan for BTV antibodies. The percent positivity recorded for buffalo was 54.05% in Punjab. A comparison of c-ELISA with dot-ELISA for a total of 181 serum samples of sheep and cattle was also done. The performance of c-ELISA relative to dot-ELISA was found to have a sensitivity of 84.61% and specificity of 89.32%.