Abstract: The present invention relates to effervescent compositions which are resistant to water vapor in the atmosphere and to methods of preparing such compositions. In particular, the invention relates to an effervescent composition comprising a co-crystal. The co-crystal comprises an acidic component and a basic component is separate. The co-crystal comprising the acidic component is resistant to water uptake avoiding initiating the effervescence prematurely. Upon dissolution of the co-crystal and the basic component effervescence occurs.

Abstract: The present invention relates to effervescent compositions which are resistant to water vapour in the atmosphere and to methods of preparing such compositions. In particular, the invention relates to an effervescent composition comprising a co-crystal. The co-crystal comprises an acidic component and a basic component is separate. The co-crystal comprising the acidic component is resistant to water uptake avoiding initiating the effervescence prematurely. Upon dissolution of the co-crystal and the basic component effervescence occurs.

Abstract: The present invention relates to a method useful for forming products which are useful in a pharmaceutical context, and products formed by such a method. The invention relates particularly, but not exclusively, to methods of forming a metastable polymorph using screw extrusion, whereby temperature and shear induce transformational changes, and products obtained or obtainable via such methods.

Abstract: The present invention provides a method of producing a co-crystal, the method comprising the steps of providing a first substance and a second substance, wherein the first and second substances are compatible to form a co-crystal, mixing said first and second substances together, and exposing the mixture of said first and second substances to prolonged and sustained conditions of pressure and shear, sufficient to form a co-crystal of said first and second substance. The prolonged and sustained conditions of pressure and shear are preferably applied in an extrusion process. Associated compositions and uses thereof are also provided.