bioavailability values in dogs of novel zoledronic acid complexes prepared by the method of invention delivered in gelatin capsules compared with the orally delivered parent compound another aspect of the invention provides modified oral bioavailability values in dogs of novel zoledronic acid complexes prepared by the method of invention delivered in enteric coated gel capsules compared with that of the parent compound another aspect of the invention provides substantial improvement in oral bioavailability values in dogs of novel zoledronic acid complexes with excess cocrystal formers prepared by the method of invention delivered in hard gelatin capsules another aspect of the invention provides slight improvement in oral bioavailability values for zoledronic acid in dogs via zoledronic acid and novel zoledronic acid complexes orally delivered through enteric coated capsules another aspect of the invention provides a reduced oral bioavailability values for zoledronic acid in dogs via novel zoledronic acid complexes with excess physical mix of coformer another aspect of the invention provides a molecular complex comprising a bisphosphonic acid or salt thereof and at least one coformer wherein the bioavailability of the bisphosphonic acid or salt thereof from the molecular complex is greater than the bioavailability of the bisphosphonic acid or salt thereof without the coformer the bisphosphonic acid may be for example zoledronic acid clodronic acid tiludronic acid pamidronic acid alendronic acid residronic acid ibandronic acid or other bisphosphonic acids known in the art another aspect of the invention provides a method for enhancing the bioavailabilty or permeability of a bisphosphonic acid comprising the step of administering to a patient.