Propranolol Hydrochloride Buccoadhesive Tablet: Development and In-vitro Evaluation

Abstract

Propranolol HCl is a beta blocker commonly used worldwide; however, it shows a low bioavailability due to its extensive first-pass metabolism. To overcome this problem, a novel drug delivery system such as buccoadhesive system might be helpful. The aim of the present investigation is to prepare the buccoadhesive tablet of propranolol HCl using different mucoadhesive polymers. Buccoadhesive tablets containing drug, lactose, and polymers such as HPMC K4M, carbomer 934P, PEO 8000000 and PEG 6000, in various concentrations, were prepared. The tablets were evaluated in terms of weight variation, thickness, hardness, friability, and mucoadhesive strength. Among thirteen prepared formulations, seven of them which had better physicochemical properties and mucoadhesive strength were undergone the release and swelling tests. Finally, two formulations were selected and uniformity, drug content, duration of mucoadhesion, and kinetic studies were performed for them. All polymers except PEG 6000 were appropriate for being used in buccal mucoadhesive systems. Formulation F₁ was considered as the most desirable formulation as it exhibited appropriate mucoadhesive strength (43.93 ± 12.4 g), extended duration of mucoadhesion (19.15 ± 0.29 h) and suitable swelling ability while having a prolonged drug release over 12 h. Although the efficiency and mucosal irritation of propranolol HCl buccoadhesive tablets should be monitored under the in-vivo conditions, however, based on the results, it seems that such tablets can be considered as an alternative route to bypass the first pass metabolism of propranolol HCl.

Keywords: Buccoadhesive tablet; Duration of mucoadhesion; Mucoadhesive polymers; Mucoadhesive strength; Propranolol HCl.

Figure 1

A schematic drawing of the apparatus used for measuring the in-vitro mucoadhesive strength of propranolol HCl formulations

Figure 2

Schematic drawing of one compartment of the apparatus used for assessing the duration of mucoadhesion

Figure 3

In-vitro release profiles of propranolol HCl buccoadhesive tablet formulations F₁, F₂, F₄, F₅, F₇, F₁₁ and F₁₃ (n = 3, mean ± SD).

Figure 4

In-vitro swelling profiles of propranolol HCl buccoadhesive tablet formulations F₁, F₂, F₄, F₅, F₇, F₁₁ and F₁₃ (n = 3, mean ± SD).

Figure 5

Duration of mucoadhesion of propranolol HCl buccoadhesive tablet formulations F₁ and F₂ (containing 40% and 30% HPMC K4M respectively) (n = 3, mean ± SD).