Formulation Development of Efavirenz TabletsEmploying β Cyclodextrin- PVP K30- SLS: AFactorial Study

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.