Loratadine (LOR) is a second generation antihistamine used to treat allergies without causing drowsiness. The activity mechanism of LOR is a competitive-reversible inhibitor of the histamine receptor tissue, and therefore, this prevents histamine binding and receptor activation [1]. LOR is a drug belonging to a class II in the biopharmaceutics classification system (BCS), which it has low solubility in water and high permeability [2]. Moreover, LOR is a weak base with a pKa of 5.0 and its solubility is affected by pH media [3]. Accordingly, LOR has the lowest solubility at pH 7.5 and the highest at pH 1.2 [2]. It is known that a drug with either poor solubility in water or low permeability often causes low bioavailability. The efforts to
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Co-crystal is a new solid form consists of a single crystalline phase of several components in a certain stoichiometric ratio, where different types of molecules that interact with hydrogen bonds or other non-covalent bonds [12]. The pyridine ring in their chemical structure LOR as shown in Fig. 1a allows the proton transfer with carboxylic acids to form a salt. Furthermore, N of the pyridine ring may also act as a hydrogen bond acceptor, allowing the formation of co-crystal when it binds to the hydroxyl group of carboxylic acids. Fumaric acid (FUM) is a dicarboxylic acid that is safe to use orally, and it’s widely employed as an excipient in salt or co-crystal formation. FUM (Fig. 1b) can improve the solubility of several drugs through the formation of salt [13,14] and co-crystals [15–18]. Provision of mechanical energy such as grinding in a solid binary mixture with or without the addition of solvents can lead to interactions, among others, an eutectic mixture, salt or co-crystal formation. The purpose of this research was mainly to prepare a binary mixture of loratadine-fumaric acid and to investigate its effect on the solubility and dissolution rate of
Co-crystal is a new solid form consists of a single crystalline phase of several components in a certain stoichiometric ratio, where different types of molecules that interact with hydrogen bonds or other non-covalent bonds [12]. The pyridine ring in their chemical structure LOR as shown in Fig. 1a allows the proton transfer with carboxylic acids to form a salt. Furthermore, N of the pyridine ring may also act as a hydrogen bond acceptor, allowing the formation of co-crystal when it binds to the hydroxyl group of carboxylic acids. Fumaric acid (FUM) is a dicarboxylic acid that is safe to use orally, and it’s widely employed as an excipient in salt or co-crystal formation. FUM (Fig. 1b) can improve the solubility of several drugs through the formation of salt [13,14] and co-crystals [15–18]. Provision of mechanical energy such as grinding in a solid binary mixture with or without the addition of solvents can lead to interactions, among others, an eutectic mixture, salt or co-crystal formation. The purpose of this research was mainly to prepare a binary mixture of loratadine-fumaric acid and to investigate its effect on the solubility and dissolution rate of